[From the U.S. Government Printing Office, www.gpo.gov]
uoy3npay 'PisvsX7 jvinjvNiof dpvi.-a A ?qifo zoumailling u! pdnssl Z66t 9 Sa9ri 9L9 LGI4 J661 U.Ivj@poojj dqj -lof (CIDWzans f dwnloA 410dq Juawssassv uv :S0104S pap A qqj Ul 4UOWOODUDVV UlDIdpoolj The Federal Interagency Floodplain Management Task Force was established in 1975 to carry out the responsibility of the President to prepare for the Con- gress a Unified National Program for Floodplain Management. Since 1982 the Task Force has been chaired by the Federal Emergency Management Agency. Membership of the Task Force consists of the Departments of Agriculture, Army, Commerce, Energy, Housing and Urban Development, Interior, and Transportation; the Environmental Protection Agency; and the Tennessee Valley Authority. -7- Design: Mike Campbell, Publications Department, Unzversi@y of Colorado. Coverphoto: Bob Cox, Floodplain Management Section, Louisiana Department of Transportation and Development. FLoODPLAIN MANAGEMENT IN THE UNITED STATES: ANAsSESSMENTREPORT Volume 1 SUMMARY Prepared for The Federal Interagency Floodplain Management Task Force Prepared by The Natural Hazards Research and Applications Information Center, University of Colorado at Boulder (Contract No. TV-72105A) 1992 VzWerty of CSC Librmy J US Department of commerce NOAA Coastal Services Center Library 2234 South Hobson Avenue Charleston, SC 29405-2413 ca Contents Preface ......................................................... 4 Acknowledgments ................................................ 5 Part 1: The Nation's Floodplains, Their Value, and Their Floods Floodplains ...................................................... 8 The Value of Floodplains .......................................... 8 Water Resources ............................................... 9 Flood and Erosion Control .................................... 9 Surface Water Quality Maintenance ............................ 10 Groundwater Supply and Quality .............................. 10 Living Resources .............................................. 10 Wetlands .................................................. 10 Riparian Systems ........................................... 11 Cultural Resources ............................................ 12 Floods ......................................................... 13 Riverine Flooding ............................................. 13 Flooding from Surface Runoff ................................... 14 Coastal Flooding and Erosion ................................... 14 Ground Failure ............................................... 15 Fluctuating Lake Levels ........................................ 16 Floodplain Losses ................................................ 16 Loss of Life and Property ............... I ....................... 18 Loss of Natural and Cultural Resources ........................... 19 Part 11: Managing Floodplains to Reduce Losses The History of Floodplain Management ............................. 24 1900-1960: The Structural, Federal Era ............................ 24 1960s: A Time of Change ....................................... 24 1970s: The Environmental Decade ............................... 26 1980s: Continuing Evolution .................................... 26 The Management Framework ..................................... 26 The Federal Government ....................................... 28 State Government ............................................. 28 Local Government ............................................ 29 Regional Entities .............................................. 29 The Private Sector ............................................ 30 Modifying Susceptibility to Damages and Disruption .................. 30 Regulations .................................................. 30 Development and Redevelopment Policies ......................... 32 Disaster Preparedness .......................................... 32 Flood Forecasting, Warning, and Emergency Plans .................. 33 Floodproofing and Elevation .................................... 33 Modifying Flooding .............................................. 34 Investment in Flood Control .................................... 35 Dams.and. Reservoirs . . .,. I...................................... 36 ' L@ -d Floodwalls ................................... 37 Dil@@s,'Levees, an Channel Alterations ........................................... 38 High Flow Diversions .......................................... 38 Stormwater Management ....................................... 38 Shoreline Protection ........................................... 38 Land Treatment Measures ...................................... 39 Modifying the Impacts of Flooding ................................. 40 Information and Education ..................................... 40 Flood Insurance .............................................. 40 Tax Adjustments .............................................. 42 Flood Emergency Measures ..................................... 43 Disaster Assistance ............................................ 43 Postflood Recovery ............................................ 45 Restoring and Preserving the Natural and Cultural Resources of Floodplains .......................................... 45 Regulations .................................................. 46 Development and Redevelopment Policies ......................... 47 Information and Education ..................................... 48 Tax Adjustments .............................................. 48 Administrative Measures ....................................... 49 Part III: The Effectiveness of Floodplain Management Perception and Awareness of Floodplain Losses ....................... 52 Recognition of Risk ........................................... 52 Awareness of the Value of Natural Floodplains ...................... 53 Knowledge, Standards, and Technology .............................. 54 Climate Change and Weather Forecasting ......................... 54 Streamflow Data .............................................. 54 Hydrology and Hydraulics ...................................... 54 Flood Forecasting and Warning .................................. 55 Soil Identification and Mapping ................................. 55 Mapping Flood Hazards ....................................... 56 Understanding and Mapping Wetlands ........................... 57 Understanding Natural and Cultural Resources .................... 57 Remote Sensing Techniques ..................................... 57 Geographic Information Systems ................................. 57 Regulatory and Design Standards ................................ 58 judicial Support for Floodplain Management ......................... 58 Constitutionality of Regulations .................................. 58 Liability for Flood Damages ..................................... 59 Avoiding Legal Problems ....................................... 59 The Present and the Future ....................................... 60 Overview .................................................... 60 Overall Effectiveness ........................................ 60 Achievements to Date ....................................... 60 The Need for Specified Goals ................................. 61 The Need for a Comprehensive Data Base .................... . 61 The Effectiveness of Management ................................ 61 Allowing for Different Approaches ............................. 61 Coordination Among Government Agencies ..................... 62 Providing for Local Conditions ................................ 62 The Effectiveness of Floodplain Management Strategies and Tools ..... 63 Modifying Susceptibility to Flood Damage and Disruption ......... 63 Modifying Flooding ......................................... 63 Modifying the Impact of Flooding on Individuals and the Community ....................................... 64 Restoring and Preserving the Natural and Cultural Resources of Floodplains ............................................ 64 Conclusion ..................................................... 65 Retrospect and Prospect -Gilbert F White ............................................ 67 Preface The coastal and riverine floodplains of the United States are highly desirable and rewarding sites for most kinds of human activities and contain a wealth of natural and cultural resources of immense importance and value to the nation. Yet they are the source of costly and frequently unnecessary losses of human life and property as well as losses of resources afforded by floodplain environments. In terms of areas affected and annual economic losses, flooding remains the greatest and most persistent natural disaster facing our nation, despite concerted efforts at all governmental levels and within the private sector to moderate, account for, or adjust to the flood risk. These efforts go back at least to the turn of this century, when initially they were focused on control- ling the paths of flood waters. Other flood loss reduction strategies and a myriad of programs have since evolved to complement these initial efforts. More recently, increased attention has been given to preserving the natural functions and resources of floodplains. This assessment of floodplain management in the United States was commissioned in 1987 by the Federal Interagency Floodplain Management Task Force. Its purpose was to provide an evaluation of floodplain manage- ment activities in order to report to the public and to the Congress on pro- gress toward implementation of "A Unified National Program for Floodplain Management" [Section 1302(c) of the National Flood Insurance Act of 1968]. Thus, it is a compilation of available information concerning the nation's flood- plains, experience with tools and strategies to reduce losses of life, property, and environmental resources, and a perspective of what has been accomplished. The assessment is presented in two parts. This summary report (Vol- ume 1) presents the salient information and findings of the full report (Vol- ume 2) and reflects both its content and organization. Sources of information for Volume 1 and additional detail, explanation, and analysis can be found in the full report. A concerted attempt was made to compile information and available data from numerous sources in an attempt to describe, evaluate, and provide for a balanced view and account of the various activities and management approaches. However, all accounts and contributions to floodplain management may not be adequately documented in this assessment due to the lack of suffi- cient information or usable data regarding certain subjects or topics. Never- theless, task force member agencies concurred with the content of this docu- ment and believe that this assessment provides the most comprehensive statement available and a foundation for action to improve effectiveness of floodplain management in the United States. It is commended to all parties who make decisions affecting floodplains and their occupants and to those having an interest in learning more about this subject. Frank H. Thomas Federal Emergency Management Agency Chair, Federal Interagency Floodplain Management Task Force 4 Acknowledgments This summary was prepared under the direction of the Natural Hazards Research and Applications Information Center, University of Colorado at Boulder, and is based on the full report prepared by L.R. Johnston Associ- ates. Both reports resulted from contractual arrangements with the Tennessee Valley Authority, which managed the national assessment effort for the Inter- agency Task Force. Principal authors of the two reports were Jacquelyn L. Monday and the late Larry R. Johnston, respectively. Countless others contributed support, information, and ideas. The Federal Interagency Floodplain Management Task Force provided funding for this study, and an Advisory Committee of the Task Force was created to provide direction and guidance throughout the work effort, including review of draft reports. The Association of State Floodplain Managers and the Asso- ciation of Wetland Managers devoted a portion of their annual conferences to provide information and input to the process. A National Review Committee, comprised of recognized experts and chaired by Gilbert F. White (one of the true pioneers of the floodplain management movement that began around 50 years ago) added valuable insight and proposed an Actw'n Agenda. Many individuals, including those representing government agencies and profes- sional and nonprofit organizations, also made important contributions by providing information, data, insights, and perspectives. James M. Wright Tennessee Valley Authority Project Manager 5 PART I TFIENAT.iON@s FLoODPLAINS, THEIR VALUE, ANDTHEIRFLOODS Floodplains Floodplains are the lowlands adjoining the channels of rivers, streams or other watercourses, or the shorelines of oceans, lakes, or other bodies of stand- ing water. They are lands that have been or may be inundated by flood water. Floodplains are shaped by dynamic physical and biological processes: climate, the hydrologic cycle, erosion and deposition, extreme natural events, and other forces. The products of the complex interrelationships of these processes are many of the nation's most beautiful landscapes, most productive wetlands, and most fertile soils, along with rare and endangered plants and animals, and sites of archaeologic and historic significance. Throughout our history, rivers and other bodies of water have been highways for exploration, migration, and commerce and have been used as disposal systems for the byproducts of indus- trial society. Almost all major cities are located on a river or at the mouth of a river. Most smaller communities have at least one stream that helps define local character and is an important source of community identity. The Floodplain with Floodway FLOODPLAIN MANAGEMENT Floodplain Management is a decisionmaking process the goal of which is to achieve wise use of the nation's floodplains. "Wise use" is any activity or set of activities that is compatible with the risk to natural resources (natural and henefi- cialfunctions offloodplains) and human resources (life and property). Compatibiliy is acheived through the strategies and tools of the Floodway Unified A7ationol Program for Floodplain Flood Fringe Flood Fringe Mana ement. 9 1 00-Year " Floodplai n Flood Fringe Floodway F.1ood Fringe a Channel The U.S. Water Resources Council estimated in 1977 that about 7%, or 178.8 million acres, of the total area of the United States, including Alaska and Hawaii, Puerto Rico, and the Virgin Islands, was within the 100-year flood- plain. The Federal Emergency Management Agency, in a 1991 study that examined nearly 17,500 mapped floodprone communities in the 50 states and the District of Columbia, estimated that there are about 94 million acres. The largest areas of floodplain are in the southern part of the country, but the most populous are along the north Atlantic coast, in the Great Lakes region, and in California. The Value of Floodplains In their natural state, floodplains have enormous but often unrecognized value. These complex dynamic systems contribute to the physical and bio- logical support of water resources, living resources, and cultural resources. Previous page. The Yellowstone River and Hayden Valley Floodplains are important to the nation's water resources because they pro- in Yellowstone National Park are a river andjbodphin vide natural flood and erosion control, help maintain high water quality, and relatively undisturbed by hurnan intrusion. contribute to sustaining groundwater supplies. Floodplains have living, or bio- logic, resource value, because they support a wide variety of flora and provide 8 habitat for fish and wildlife. The cultural resources of floodplains include the .maintenance of a harvest of natural products, places for recreation, scientific study, and outdoor education, and sites of historic and archeological interest. Although the value of these resources is now well recognized ,and most of the processes contributing to them reasonably well understood, it has proven difficult and sometimes impossible to assign economic values to the functions served and benefits provided by floodplains. Water Resources Water can be put to human use either while it is in the stream or other water body or when it is diverted and used elsewhere. Offstream, surface water can be used for irrigation, for industrial and municipal purposes, and energy production. These uses reduce the flow or level of water, at least tem- porarily, and inevitably degrade its quality somewhat. Instrearn uses of water include navigation, fish and wildlife propagation, waste transport, hydropower Coastal barriers are constantly changing landjorms. They generation, agricultural and industrial uses, recreational activities, and sup- protect much of the Atlantic and Gu@f coast from the direct plying drinking water. Instream uses usually require a minimum flow or effects of htgh water waves, currents, and severe storms. water level and hence tend to compete with offstrearn uses. Development on a coastal barrier, Grand Isle, Louisiana. Flood and Erosion Control Natural, unaltered floodplain systems can reduce flood velocities, reduce flood peaks, and reduce wind and wave impacts because their physical charac- teristics affect flood flows and, typically, provide space for the dispersal and temporary storage of flood waters until the natural drainage can carry them away. This natural function obviously can reduce the potential damages and loss of life from floods. One acre of a floodplain can store about 325,000 gallons of water if flooded to a depth.of only one foot. Floodplain vegetation, Natural and Cultural Resources of Floodplains Water Resources Natural Flood and Erosion Control Surface Water Quality Maintenance � Reduce flood velocities 0 Reduce sediment loads � Reduce flood peaks * Filter nutrients and impurities � Reduce wind and wave impacts 0 Process organic and chemical wastes � Stabilize soils 0 Moderate temperature of water 0 Reduce sediment loads Maintain Groundwater Supply and Quality 0 Promote infiltration and aquifer recharge 0 Reduce frequency and duration of low flows; i.e. increase/enhance base flow Living Resources Support Flora Provide Fish and Wildlife Habitat 0 Maintain high biological produc- 0 Maintain breeding and feeding grounds tivity of floodplain and wedand * Create and enhance waterfowl habitat' vegetation * Protect habitat for rare and 0 Maintain productivity of natural endangered species forests 0 Maintain natural crops 0 Maintain natural genetic diversity Cultural Resources Maintain Harvest of Natural and Provide Opportunities for Recreation Agricultural Products 0 Provide areas for active and 0 Create and enhance agricultural lands consumptive uses 0 Provide areas for cultivation of fish 9 Provide areas for passive activities and shellfish 0 Provide open space values 0 Create and enhance forest lands 0 Provide aesthetic values 0 Provide harvest of fur resources Provide Areas for Scientific Study and Outdoor Education � Provide opportunities for ecological studies � Provide historical and archaeological sites 9 especially in wetlands, can reduce erosion by binding the soil with its root sys- WETLAND FLOODPLAINS tems. Moreover, friction between the vegetation and the water dampens waves HELP MAINTAIN WATER QUALITY and reduces current velocity. Coastal barriers- elongated, offshore formations of sand and other unconsolidated sediments lying generally parallel to main- 0 Studies of heavio polluted watersflowing through land coastlines- protect large portions of the coast, including estuaries, bays, Tinicum Marsh in Pennsylvania have revealed sig- and wetlands, from the direct effects of high water, waves, and currents nz)'icant reductions in biological oxygen demand, caused by both normal and storm conditions. phosphorous, and nitrogen within three tofive hours. 0 The value of Georgia's 2,300-acre Alcovy River P_41;.77 w`- Swamp for water pollution control has been esti- mated at $1 million ayear. The bottoinlandforested CA wedands along the river have been shown to filter V impurities from flood waters. 7 Ok at f rX 4 '7 4? Floodblains and wetlands not only help maintain water qualiy, they also provide a natural environment for diverse species. Bottomiand hardwood swamp, Louisiana. Surface Water Quality Maintenance Natural floodplains can reduce the cost of waste water treatment and water quality maintenance; they can reduce sediment loads, process chemical and organic wastes, and reduce nutrients, thereby protecting the physical, bio- logical, and chemical integrity of water. Floodplains buffer rivers, streams, lakes, and estuaries from upland sources of pollution. Groundwater Supply and Quality Conditions beneath undisturbed floodplains can facilitate the infiltration and storage of water, permit groundwater recharge, purify water entering the aquifer, reduce flood peaks, and ameliorate the frequency and duration of low flows in groundwater systems. These functions help maintain and improve conditions for municipal and private wells, wildlife, irrigation, and watering livestock during drought. Living Resources Floodplains are among the most productive of the planet's ecosystems. Q Because of their relative abundance of water, they provide habitat for a mul titude of plant and animal species, and the energy and nutrients from their healthy function are passed along to organisms in adjacent and down 4,_ stream areas. Wetlands Wetlands are perhaps the most prominent and familiar of floodplain J resources. They are lands transitional between terrestrial and aquatic systems and are covered by shallow water or have a water table at or near the surface. T here are slightly in excess of 100 million acres of wetlands in the 48 con- OQ0 ates, and the majority of these are in floodplains. Florida, Loui- tiguous st x siana, and Alaska have the most wetland acreage. Rzparion habitats sustain ecosystems that include many Wetlands are classified by the U.S. Fish and Wildlife Service according to large mammals such as bear, white-tailed deer, and five ecological systems, of which estuarine and palustrine wetlands are best caribou. known. Estuarine systems include such coastal wetlands as salt and brackish White-tailed deer, St. Andrews Bay, Florida. tidal marshes, mangrove swamps, and intertidal flats, as well as the deepwater 10 habitats associated with bays, sounds, and coastal rivers. Palustrine wetlands account for about 90% of all U.S. wetlands. They are inland, freshwater areas of marshes, bogs, and swamps, and some brackish and salt marshes in and FLOODPLAINS AS HABITAT and semi-arid areas. e Black ducks migrating in the Atlanticflyway use . Wetland plants are particularly efficient converters of solar energy. Their the northern salt marshes as their primary wintering major food value is achieved when they die and fragment to detritus. Numerous grounds. fish and wildlife species feed in marshes and swamps or on organisms that 0 Intertidal mudflats along the coasts are the prin- were produced in such areas. Some animals spend their entire lives in flood- cipalfeeding grounds for migratory shorebirds, most plain wetlands, while others use the wetlands primarily for reproduction, shorebirds breed in Alaskan and other tundra ue ilands. * Mississippi River floodplain s are the major resting andjeeding groundsfor ducks and geese during their Typical Inland Wetland fall and spring migrations, * During droughts in the prairie pothole region, Alaska's wetlands are heavi4, usedfor nesting by North American waterfowl. 0 Hawaii's wetlands are especially important to endangered birds. Upland Arizona's native cottonwood- willow associations Upland support higher densities and a greater diversity of A Upland breeding birdspecies than an Gr nd..ater _y other desert habitat. n High Water lsharge .- - @=@ 1 1 @ The prairie pothole region of the Dakotas is the tree rn' Low, Watei 7 Wati in breeding areafor wole7fowl in the LInited States. River ------ The San Pedro River's riparian ecosystem in Seepage Wetland Overflow Deepwater Overflow Depressional southeastern Arizona provides nesting, migratory, or on Slope Wetiand Habitat Wetland Wetland wintering habitatfor at least 20 rapier species and about 210 species of other birds. A stud .y recorded 78 species of mammals in the grasslands corridor nursery grounds, or for drinking water. About 50% of the endangered species between the riparian woodlands and adjacent moun- tains, the second-hughest mammalian diversity in the in the United States require wetland habitat at some point in their life cycles; world. wetlands are crucial to the survival of the American crocodile, the manatee, the whooping crane, and the Mississippi sandhill crane. Both coastal and inland wetlands also provide valuable habitat for such furbearers as muskrat, beaver, otter, mink, and raccoon, as well as numerous reptiles and amphibians. Large mammals, such as black bears, white-tailed deer, and caribou, also find refuge and food in wetland areas. Riparian Systems Riparian floodplains are distinct associations of soils, flora, and fauna that occur in narrow strips along rivers, streams, or other bodies of water and depend for survival upon high water tables and occasional flooding. They are Canvasback duck, salt marsh, New England. r A Great blue heron, Merrimack River, New Hampshire. A:@ Healthy riparian ecosystems are essential for maintaining the biological diversiy of the nation's fiora. They also provide aesthetic pleasure, Wetlmd vegetation, Joyce Kilmer Memorial Forest, North Carolina. generally more biologically diverse than the surrounding uplands and encom- pass a broader range of moisture and soil conditions and a greater diversity of flora and fauna than wetlands do. The Soil Conservation Service estimates that there are 16 million acres of riparian land along streams, canals, lakes, reservoirs, and tidal shorelines of rural, nonfederal portions of the United States. Bottomland hardwood forests also are a major riparian ecosystem, and they account for about 52 million acres, mostly in the South. Healthy riparian ecosystems provide community structure for raptors, safe passage corridors to water for mammals, habitat for amphibians, and cover and nutrients for fish. At elevations below 3,500 feet, they take the form of lush strips of streamside vegetation that interrupt' the desert landscape. These linear communities provide habitat for up to 801yo of the West's wildlife species, and are essential for maintaining its healthy fish and wildlife popula- tions. Cottonwood groves provide a high canopy and open understory essen- 4 tial to certain birds of prey for hunting, while mesquite bosques provide lower, denser ve tation ideal for colonial nesting by whitewing doves. Also depen- ge Rivers andjloodplains provide numerous recreational dent on riparian habitats are grey squirrels, river otters, muskrats, summer opportunities-including hiking, camping, hunting, fish- tanagers, canyon frogs, tree frogs, and dove-tailed hawks. ing, boating, swimming, bird-watching, picnicking jog- ging, photography, ice skating and szmp@ observing nature. Above: Bicyclist, Boul&r Creek Pathway, Boul&r, Colorado. Below: Canoer, Nantahala River, North Carolina. N, "T Arid region _floodplains, although apparently desolate, actually provide habitat for most desert wildlife species. Channel, floodplain, and rzparian habitat, Verde River, Tonto National Forest, Arizona. Cultural Resources As used in this report, the cultural resources of floodplains include their historic and archaeological sites, their scientific, recreational, and aesthetic 6@ uses, as well as the harvest of the floodplains' natural and cultivated products. Because water has always been basic to human survival, transportation, and commerce, many sites of historic and archaeological significance lie in flood t plains. Floodplains provide opportunities for hiking, camping, hunting, fish ing, boating, swimming, bird-watching, picnicking, jogging, photography, ice skating, nature observing, as well as for scientific study and research, educa- tional activities, and less tangible aesthetic benefits. Floodplains can provide urban communities with a tremendous open-space and greenbelt resource. Inland floodplains are great sources of commercial timber. Much of the 82 million acres of commercial forested wetlands in the 49 continental states lies within floodplains. The standing value of southern wetland forests alone is $8 billion. The floodplains along larger rivers are prime agricultural lands because of their flat terrain, abundant water supplies, and rich alluvial soils periodically replenished by flooding. From 1956 to 1975 about 60% of the U.S. commercial fish and shellfish harvest was made up of wetland-dependent species. Several billion dollars are generated annually from this harvest and from wetlands-dependent sport fishing. 12 Floods Floodplains are, by definition, lands that are formed by and continually sub- ject to inundation by water. Depending on the location, topography, soils, and weather conditions, that flooding can take a variety of forms. Riverine floods can result not only from heavy rainfall and rapid snowmelt but also from dam and levee failure, ice jams, and channel migration. Coastal flooding can be caused by hurricanes, winter storms, tsunamis, and rising sea level. Indi- vidual storms and long-term climate variations cause flooding around lakes. Other floodprone areas include alluvial fans, unstable and meandering chan- nels, and areas affected by land subsidence and ground failure. In addition, flooding due to surface runoff and locally inadequate drainage can be a major problem, particularly in rapidly urbanizing areas. Riverine Flooding Riverine flooding-overflow of water from the channel onto the adjacent floodplain-is the most common type of flood. Hundreds occur each year in the United States. Flashfloodng occurs in all 50 states: in narrow, steep valleys, on alluvial fans, on denuded areas, and along urban drainage courses, usually as a result of high intensity, short duration storms occurring on steep gradient streams. Flash floods can be more dangerous than other floods because of their suddenness, the velocity of the water, and the large amount of debris carried by the flood waters. 7 Raw Examples of'Recant Flash Floods Causing Serious Loss of Life February 1972, Buffalo Creek, West Virginia-125 killed and hundreds of homes washed away when a dam made of coal mine waste material gave way after heavy rains. Big Thompson Canyon, Colorado, follo-ing fl-h flood, July 1976. June 1972, Rapid City, South'Dakota an(fadjacent areas-236 dead and $100 million in property damage after a large, slow-moving thunderstorm unleashed heavy rain on the slopes of the Black Hills. July 1976, Big Thompson Canyon, Colorado-139 killed and millions of dol- lars in property damage after a thunderstorm inundated the western third of the canyon with 12 inches of rain in less than six hours. July 1977, Johnstown, Pennsylvinia-77 dead and more th -an $200 million in property damage when violent thunderstorms produced 11 inches of, rain over a seven-county area in nine hours. Several dams failed, compounding thestream flooding and causing 40 of the deaths. September 1977, Kansas City, Missouri, and adjacent areas@25 killed and $90 million in property damage when diundersto 'rms turned several.streams into raging torrents, including "gentle" Brush Creek, which flows through the heart of Kansas City. VN Source: Federal Emergency Management Agency � Alluvialfanflooding can cause great damage because of the high veloci- Alluvial fan j7ooding at the mouth of ravines or the foot of mountains occurs throughout the United States, but is most ties, large amounts of sediment and debris, and wide area covered by prevakni and poses the greatest hazard in the arid West. the flood waters. Alluvial fans occur mostly along the base of moun- Mobile how park, Colorado river, near Parker, Arizona. tains in the western states. An estimated 15-25% of the and West, including Los Angeles and Las Vegas, is covered by alluvial fans. � Unstable and meandering stream channels are also frequently flooded. Many of them are the product of several decades of human activities, particularly in the and and serni-arid West. Overgrazing, mining, forestry, urbani- zation, gravel and sand extraction, and the construction of railroads, 13 highways, dams, and irrigation facilities all have changed the vegetative cover, altered surface water patterns, changed the movement of sedi- ments, and lowered water tables. These changes have made water movement during floods difficult to predict. Icel'ains, which affect 35 states, cause a rapid rise of water both at the point of the jam and upstream; when the jam breaks, sudden down- stream flooding results. Because the waters are higher and their veloci- ties greater, damages usually exceed those that would have occurred without the jam. Additional damage can be caused by the force of the ice, as it builds in volume and expands overbank during the jam and Storm drainage is a significant problem in many large then crashes downstream when the jam breaks. urban areas, particularly if development has been rapid and not well planned, Drainage systems must be designed Flooding from Surface Runoff to handle infrequent, but potentially catastrophic, events. The runoff from heavy precipitation can overtax inadequate local drain- Concrete-lined artificial channel carryingflood waters, Baton Rouge, Louilmna. age systems and result in flooding outside of normal floodplains. These kinds of flooding problems generally intensify as areas become more urbanized. Frozen ground and heavy accumulations of snow can exacerbate the problem. Coastal Flooding and Erosion Coastal flooding and erosion result from storm surge (the rise in the water surface due to barometric pressure and the piling up of water as a result of wind) and wave action (the combination of wave set-up and wave runup). The frequency and magnitude of flooding and erosion vary consider- ably across the country@ 0 From 1899 to 1989 a total of 148 hurricanes and 135 tr*al slomu crossed or passed adjacent to the U.S. mainland. e Northeasters-extratropical storms accompanied by strong winds-cause flooding along the north Atlantic coast. 0 Tsunamis are sea waves generated by undersea earthquakes of over R6.5; -period, are of low height at sea, and can travel over they are very long 500 mph. The entire Pacific coast of the United States, including Alaska and Hawaii, is subject to tsunamis. 0 Shoreline erosion occurs either when storm surge and wave action move sediment offshore or when the alongshore flow of sediment is inter- rupted by natural forces or human activities. Natural erosion may be accelerated by partial or inadequate structural or nonstructural meas- W. ures intended to protect short reaches of eroding shoreline-such as Hurricanes can result in flooding of various kinds, from beach nourishment, artificial dunes, breakwaters, seawalls, bulkheads, flashflooding and slow-rise riverine flooding due to heavy revetments, groins, andjetties. precipitation, to coastalflooding due to storm surge. Quinebaug River, Putnam, Connecticut, 1955, following 0 Hurricane Diane, Number of Major Hurricanes Directly 5 0 -2 Affecting the United States, 1899-1989 3 0 4 4 0 Hurricanes can cause severe clamage due to the combined 6 5 effects of several agents-high winds, increased wav e ac- 15 1 tion, heavy precipitation, storm surge, and other types of flooding. Damage near Charleston, South Carolina, following Hur- 22 ricane Hugo, September, 1989. Q, 14 Source: National Hurricane Center, National Weather Service Ground Failure Areas subject to ground failure often suffer from nwdAws and mudfloods, two forms of landslides. Urban development alters hillslope configurations and upsets established equilibrium, triggering the natural instability of many slopes and sometimes reactivating old landslides. Mud and debris may fill drainage charm els and sediment basins, causing flood waters to suddenly inundate areas outside the floodplain. Mud flows and mud floods may cause more severe damage than other flooding because of the force of the debris- filled water and the combination of debris and sediment. Both,natural and human-induced subs&ence can increase flood damage in areas of high groundwater, tides, storm surges, or overbank stream flow. It can also block or otherwise alter drainage patterns, leading to deeper or unex- pected flooding. Subsidence occurs in at least 38 states. Lique t' is a type of ground failure triggered by seismic waves passing .fac wn through unconsolidated and saturated soil. Depending on the character of the jAr 'r soil, the amount of water, and the drainage potential, the soils may sink or become liquid. This can result in serious flooding of structures built on fill or saturated soils-as in parts of San Francisco and Anchorage. 01 X Natural coastal erosion can be great@v accelerated by wave action during storms and hurricanes. Combined with inap- propriate construction in coastal areas, this natural process can result in disaster, Big Rock Beach, Malibu, California, following PaciJic winter storm, 1983. C *W, Mudflows and mudfloodf are two types of landslides that can be aggravated by human development. Addi- tionally, they can resultfrom other natural hazards, such as earthquakes and volcanic eruptions. Toutle River, Wohin,,ton State, followin,, the eruption of Mt. St. Helens, May 1980. 14 15 Fluctuating Lake Levels Closed-basin lakes are susceptible to dramatic (5- to 15- foot), long-term fluctuations in their water levels as a result of variations in precipitation, run- off, and evapotranspiration. Flooding associated with this situation can last for years; examples of such lakes are the Salton Sea, the Great Salt Lake, and the Great Lakes. Short-term fluctuations can be triggered by sustained strong winds and by sharp changes in barometric pressure. Human activities, such as dredging, diversions, water consumption, and regulation by structural works, can also affect lake levels. Changes In Water Levels in the Great Lakes, 1900-1986 (Lake Sur-face Elevation, in Feet) Lake Monthly Mean I Range 1900-1986 (Winter low to summer high monthly means) Average Maximum Minimum Average Maximum Minimum Superior 600.61 602.24 598.23 1.2 2.1 0.4 Michigari-Huron 578.33 581.62 575.35 1.2 2.1 0.4 St. Clair 573.40 576.69 569.86 1.7 3.3 0.4 Erie 570.50 573.70 567.49 1.6 2.8 0.9 Ontario 244.73 248.06 241.45 2.0 3.6 0.7 Levels are referenced to International Great Lakes Datum 1955. Source: U.S. Army Corps of Engineers Floodplain Losses Am@- Throughout the history of the United States, the prevailing view has been that humans should use and modify the natural environment, including flood- plains, to meet their needs. For centuries people have been settling on the banks of the country's rivers, streams, and oceans, taking advantage of the water supply, transportation, energy source, wildlife habitat, and other benefits flood- plains provide. Unfortunately, human development on floodplains usually results in flood damages. In the United States the result of this widespread damage was a second wave of activity, during which individuals and govern- ments enthusiastically engaged in the construction of dams and reservoirs, levees, floodwalls, and stream channelization projects in efforts to prevent toricaly, the development of the United States has or limit damages to development that was either knowingly or inadvertently procee&d along the principal waterways of the nation, placed within the floodplain. Thousands of water supply projects, particularly where cities have been developed and redeveloped over the in the and West, dramatically changed the natural resources of riparian areas. &cades. Millions of acres of inland and tidal wetlands were filled or drained, causing Pittsburgh, Pennsylvaiu@, early 1960s. loss of natural flood storage areas, a lowered capacity for filtration of pollu- (Compare this photograph with those on page 24.) tants and groundwater recharge, and reduction or elimination of some wildlife species. By the late 1970s it was estimated that from 3.5 to 5.5 million acres of floodplain land had been developed for urban use, including more than 6,000 communities with populations of 2,500 or more. Annual growth in these floodplain areas was between 1.5% and 2.5% during the 1970s, roughly twice that of the country as a whole. The coastlines of the United States have been attracting people and their accompanying property and infrastructure in ever- increasing numbers for several decades. The 1980 U.S. Census units within 50 miles of the Atlantic and Gulf coastlines increased in population from 34.1 million in 1940 to 63.3 million in 1980-an increase of 857o, compared with 707o for the nation as a whole. The population of Gulf Coast counties increased by 2007c. In 1991 the floodplain lands in 17,466 examined communities occupied a total of 146,600 square miles (93.8 million acres), including about 9.6 million 16 households and $390 billion in property. Florida was the state with the highest composite risk, followed by California, Texas, Louisiana, and New Jersey. This large-scale development and modification of riverine and coastal floodplains has resulted in a major increase in the land area of the United States that may be economically developed and used, but at a high price extracted annually in deaths, personal injury and suffering, economic loss, and damage to or destruction of natural and cultural resources. There are two main kinds of floodplain losses: loss of life and property, and loss of natural and cultural resources. Both types continue to occur even with increased aware- ness of the value of floodplains and of the risks of floodplain occupancy. The actual and relative amounts of these losses are not well quantified. 44 It has been estimated that 3.5 to 5 5. million acres offloodplain land had been developedfor urban use by the late 1970s. In many cases, this change has resulted in greatly altered river corridors and adjacent lands. Channel modification, Sioux Ciy, Iowa. Average Annual Flood Damages for Five-Year Periods in the U.S., 1916-85 5500 5000- Although there is no unifornz measure offlood losses, Damages flooding clearly constitutes the most pervasive and costly 4500- hazardfacing the nation. From 1965 to 1989, total as- sistance payments for Presidentially declared disasters 4000- Damages (1985 $) amounted to almost $6 8 billion. Of that, $5.2 billion La was allocated for flood- and hurricane-related damage. .9 3500- DamageS/200 million population Flooding, Prairie du Chien, Wisconsin, 1975. 6 a (1985$) %_ 3000- 0 U) 2500- 2000- 0 1500- 1000- 500 0 1920 25 30 35 40 45 50 55 60 65 70 75 80 85 Last Year of Five-Year Period Source: National Weather Senice Loss of Life and Property Between 1916 and 1985 there were, on average, 101 flood-related deaths annually; there is no indication that deaths are increasing or decreasing on a per capita basis. On the other hand, there definitely was an increase in flood damages over that 70-year period. Per capita flood damages were almost 2.5 times as great from 1951 to 1985 as from 1916 through 1950, after adjusting for inflation. Property losses from floods appear to have been fairly constant in relation to the overall national economy. For example, flood losses in 1937 in the Ohio and lower Mississippi River basins ($440 million) amounted to .00497o of the GNP for that year. Flood damages in 1983 ($4 billion) Although less dramatic than urban or coastalflooding, amounted to only .00127o of GNP. Consistent, reliable data on historic flood ruralflooding and consequent agricultural losses account deaths and damages are still not being collected. Information on the financial for almost 50To offlood damages in the United States. aid given by many federal and state agencies is not available in a form that Flooding along the Snohomish River, Washington State, separates flood-related damages from other types of natural and technological November 1986. disasters. Nevertheless, there are numerous figures available to help establish the type and extent of damages suffered. 0 Floods account for more losses than any other natural disaster in the United States (with the exception of drought losses during certain years or long-term periods). In most years flood damages constitute the bulk of federal financial aid for disasters. 0 From 1981 to 1985, about 23% of all Presidentially declared disasters -7 involved coastal flooding, and about 49% of federal disaster aid obliga W71 tions were attributable to coastal damage. 9 A total of $2.6 billion in flood insurance claims were paid out by the National Flood Insurance Program from 1978 to 1987. Over 31% were -year floodplain-the result of for flooding in areas outside the 100 rapid urbanization that exceeds the capacity of managers to remap and Damages to inftastructure may account for as much as regulate, or to manage stormwater. 25 % of the total damages incurred during flooding 0 The Federal Highway Administration provided $442.3 million in emer- Bridge damaged by _flooding, Jefftrson Island, Louisiana, gency relief from 1986 through 1989. 1979. 0 About half of the nation's annual flood damages are agricultural losses. 0 The Small Business Administration issued $78.7 million in economic injury disaster loans and $67.9 million in physical disaster loans in fiscal year 1989. 0 On irrigated cropland, flooding can damage irrigation facilities, such as ditches, pipelines, and sprinklers. Sediment deposited by flood T, waters can reduce long-term yield by covering fertile land with infertile deposits and can damage existing crops by interfering with their growth. These losses range from $150 to $500 million annually. 0 A review of eight disasters from the 1950s and 1960s found that damages to infrastructure accounted for about 25% of the total damages. Other estimates put that figure at 10-19%. In a 1971 study, the Corps found that approximaie@y 0 Over three-fourths of all Presidentially declared disasters involve flash 24 To of the nation's shoreline was significantly eroding. flooding; flash floods have been the cause of most weather-related deaths Two-thirds of this land was privately owned. in the United States. Dune erosion and house collapse, Sandwich, Mas- sachusetts. 0 A study of streambank erosion estimated $295 million in average annual damages. Neither the damages from nor costs of coastal erosion have been estimated. 0 Total national losses from lake level fluctuations exceeded $250 million from 1981-1986. 0 The overall damages and cleanup costs from the 1980 eruption of Mt. St. Helens, which caused catastrophic flooding and mudflows, were estimated at $1.2 billion; over $875 million was needed to restore land, clean up rivers, and provide flood protection to area communities. 0 Three tsunamis have resulted in losses in recent times: 173 deaths in Hawaii in 1946; 61 deaths in Hawaii in 1960; and 107 deaths in Alaska, 4 in Oregon, and 11 in California in 1964, plus $100 million damage on the West Coast. 18 Streambank Erosion Average Annual Damages in $ Thousands P 'fic-North t So ns-_Re_d-AP-nr-_ New Engl n 1,200 per sissi i r 5,ii @ 0 ':@"jat L 7 real Be @n,@ Misso ri Basin 500 S@ 16, The Corps estimates that in the United States there are alifor 'a hioVallO 574,500 miles ofstrearn bank with erosion problems- 5 56,200 i@-@40 Basin iddle Atlantic 142, 100 with serious problems. About 78 % of all stream 4,P e Y 10,900 bank erosion takes place west of the main stem of the I Mississippi River. LArkan as-W te- ed 350 Rio Grande Low r A Will 38, Texas ulf Sout At ntic Gulf 2SI 00 it 1 000 W L=0 __J U.S. Total $294,600,000 Source: U.S. Army Corps of Engineers Loss of Natural and Cultural Rcsources All three types of floodplain resources-water, living, and cultural-are threatened by human use of the floodplain, whether for urban development or seemingly benign agriculture or forestry. Furthermore, because floodplains are integrated natural systerns, tampering with any one of the component natural processes may often lead to trouble. Increased runoff resulting from wide- spread clearing of vegetation, destruction of wetlands, dune removal, paving, roofing, and other activities can increase flood peaks, stream erosion, and sediment transfer. Blocking runoff or interrupting the movernent of ground- water can raise flood profiles, increase pollution, and interfere with ground- water balances and the distribution of sediment. Fertilizers, septic systems, chemical and petroleum spills, and leached materials from waste disposal areas can degrade the surface and groundwater resources of floodplains. Recreational and commercial river traffic often seriously contributes to stream- bank erosion. Increased sediment can bury food sources and spawning areas 7W and pollution can poison plants, animals, and other living things. Develop- Human occupation and use of a Jlooaplain threatens its natural resources in many ways. Sign@ficant arwng these ment can remove shelter and food, and prevent fish and other wildlife from is the potentialfor increased pollution due to improper moving through their habitat. Erosion of coastal wetlands and filling of wet- waste disposal, spills, and various forms of nonpoint lands destroys habitat. In many cases, developed floodplains do not have the source pollution. aesthetic and recreational attributes of natural ones. Improper agricultural and forestry practices can be just as destructive of natural floodplain values as poorly planned urban development. The nature of the value of natural floodplains makes the damage to them difficult to quantify, but the losses have been assessed even if no economic value has been assigned. Over 90% of the United States' coastal barriers are subject to flooding and erosion because of their seaward exposure, inherent instability, and relatively low-lying topography. In spite of these risks, 14% of the area of coastal barriers is urbanized (compared to only 3 % of the entire mainland), including Atlantic City, Ocean City, Virginia Beach, and Miami. This development also interferes with the natural ability of the barriers to absorb storm energies, thereby reducing protection for mainland populations and development as well. 19 F'' must be carefulo just as urban development offloodplains planned, the effects of agricultural andforestry uses must also be analyzed and un&rstood before changes in a j7ood- 0 plain are made. Connecticut River near Deerf@rld, Massachusetts. Jor- J Development in a j7oodplain may 1) increase runoff, 2) block runoff and interrupt groundwater movement, and 3) increase pollution, It can affect living resources and habitat in numerous, sometimes unpredictable, ways. Development in coastal marshland of Louisiana. 0 Human activities have already profoundly affected floodplains and the nature of flooding throughout the and and semi-arid Southwest, where rapid development is expected to continue. Many changes that began 450 years ago with the introduction of cattle are still affecting the basic hydrologic cycle and geomorphology of the region. Plant and animal associations that evolved for 10,000 years have been irreversibly altered, and the effects of this are still only vaguely understood and generally unmanaged. About 54% of the original 215 million acres of wetlands in the nation Over the years, the conversion of wetlands to other uses has resulted in more than heq of all US. wetlands being lost. have been lost since European settlement. A recent U.S. Fish and Dredging near Amelia, Louisiana. Wildlife Service study estimates that there are about 100 million acres, or about 55o of the land mass, left in the continental United States, and the U.S. Office of Technology Assessment estimates that there are about 200 million acres, or about 60%, in Alaska. Historically, the greatest portion of this loss by far was the result of draining wetlands Original and Remaining Acreages of Wetlands in the Lower 48 States Lost (54%) Remaining (46%) Source. Fish and Wildlife Service, U.S. Department of the Interior 20 for conversion to agriculture. Major areas of bottomland hardwood forests have been cleared, drained, or converted to agriculture. Agricul- tural uses were estimated to account for 54ro/o of the 300,000 acres lost annually from the mid-1970s to the mid-1980s. Riparian ecosystems are being degraded and destroyed throughout the United States. The lower 48 states originally contained 75-100 million acres of indigenous, woody riparian habitat, but today only 35 million remain in nearly natural condition. The rest have been inundated by reservoirs, channelized, dammed, riprapped, converted to agricultural use, overgrazed, paved, or altered by a combination of factors that have impeded their ability to stabilize and maintain the biological diversity of their own watersheds. Riparian habitats have been lost in every region of the country. Channelization and other flood control projects can destroy riparian habitat by clearing vegetation; eliminating sandbars, islands, and pro- ductive backwater areas; and accelerating bank erosion. Between 1940 and 1971 the U.S. Army Corps of Engineers assisted in navigation and flood control projects to alter 11,000 miles of streams. The Soil Conser- vation Service has installed 10,700 miles of channel modifications. Dams can alter riparian habitat in many ways, such as drowning it under reservoirs, desiccating it by downstream dewatering, or render ing it non -regenerative by interrupting the natural flood cycle. The nation's 68,153 nonfederal dams have altered or destroyed tens or hun- dreds of thousands of miles of riparian habitat. Impoundments by the Alteration is widely used to controlflooding by increasing federal government have transformed major river systems, including the carrying capaci!y of a stream channel. Techniques in- clude straightening, deepening, widening, or paving the the Columbia, Colorado, Missouri, and Tennessee, into a series of channel; removing debris; raising or enlarging bridges and artificial lakes, severely decreasing the diversity of habitats available culverts; removing dams and other obstructions; and in- to wildlife but creating other habitats and environments. stalling underground conduits. However, unless carefully planned and executed, such channel modificatton can sig- By overgrazing, trampling vegetation, compacting the soil, and break- nzficant@v affect riparian habitat, ing down streambanks, livestock have seriously damaged watersheds Artificial channel (buried conduit) under construction, and riparian zones. These impacts have led to increased soil erosion, LaPlace, Louisiana. higher nutrient load in streams, bank erosion, and lowering of water tables. Inadequate livestock management has been responsible for the serious lack of riparian habitat regeneration on federal rangelands in the West. Lowering of the water table in and and semi-arid regions causes a drastic and often permanent degradation of the floodplain. In many areas, a high water table and accompanying pools and springs are the only sources of moisture for riparian vegetation and native animals. Introduction of non-native plants has also significantly contributed to alteration of floodplain habitat. Salt cedar, for example, which was imported to North America during the 19th century, has become the predominant riparian tree species on the lower Colorado, the lower Rio Grande, and Pecos rivers. It covers some 500 square miles in those basins alone, and makes the riparian areas less suitable to many native birds. The introduction of cattle to the American West has had a fundamental effect on the nation's landscape-in particu- lar, on riparian lands in semi-arid environments. In many cases the result has been soil compaction, loss of vegeta- tion, increased erosion, and the consequent deterioration of floodplains, river banks, and river water quality. 21 PART II MANA'C,INGFLooDPLAIN'S TO.RtDUCE LossES - The History of Floodplain Management Before 1965, government action to reduce floodplain losses was primarily a response to significant loss of life or property damage. Most of these efforts sought to control flooding through structural measures. During the mid-1960s, federal policy began to broaden to include nonstructural means. The last 25 years have witnessed a major expansion in floodplain management, incorpo- rating better ways for analyzing and predicting flooding, paying appropriate attention to the natural resources of floodplains, and adjusting the roles of federal, state, and local governments and the private sector. 1900-1960: The Structural, Federal Era During the 1800s and early 1900s, flood control efforts were undertaken by levee districts, conservancy districts, other local and quasi-public groups, and individual landowners. Federal involvement was sporadic and concerned mainly with flood impacts on navigation, forestry, or agriculture. After the Civil War, Congress authorized federal agencies to begin stream gaging as a start toward flood forecasting and warning, but federal involvement still was limited. After two decades of major flooding along the Mississippi, Ohio, Potomac, Susquehanna, and various New England rivers, Congress com- mitted the federal government to flood control of all navigable rivers in the nation in the Flood Control Acts of 1917, 1928, 1936, and 1938. The com- bined effect of these acts was the federal government's assumption of the full cost of building and maintaining reservoirs and channel modifications, and the placement of most of the responsibility for efforts to control floods in the hands of the Corps. These laws did mention other measures for reducing flood damages, such as evacuation, watershed improvement, and reconcilia- tion of needs of upstream and downstream users, but the emphasis was on controlling flooding with such structures as dams, levees, and channel modifications. Twenty-five years later the Corps' authorized flood control program encompassed 220 reservoirs (90 million acre feet of flood control capacity), over 9,000 miles of levees and floodwalls, and 7,400 miles of channel modifi cations-a total of 900 projects with an estimated federal cost of $9 billion. Other federal agencies also became involved in flood control. The Tennessee In the kiter part of this century, the scope of floodplain Valley Authority's regional program of resource development included con- numagement broadened to encompass a wide range of tech- struction of dams and reservoirs for flood control and other purposes. The niques. The "Point Area" of Pittsburgh, fenmylvania, at Bureau of Reclamation and the U.S. Department of Agriculture began the confluence of the A14heny and Monongahela Rivers, including flood control with other project considerations. During the 1930- demonstrates these advances. For example, the transporta- 1950 period the U.S. Forest Service established research watersheds to study tion corridor in thefireground has been replaced by an i Id and timing of flows from forest and range watersheds. The open spa-ce park, highways have been eleevaled, and promi- water yie 1 nent structures have been floodproofed. These physical Coweeta Hydrologic Laboratory in North Carolina was established in 1934 changes, along with a comprehensive system of upstream as the first of these watersheds. The Soil Conservation Service began helping flood control, land use controls, and a coordinated flood individual landowners in 2,600 soil conservation districts to use conservation warning and preparedness program, have signifi@anty measures, including flood prevention. reduced theJZood hazard in downtown Pittsburgh. Along with federal involvement *in flood control came federal relief for Above: Pittsburgh, Pennsylvania, Point Area 1948. 1 Below: Pittsburgh, Pennsylvania, Point Area 1982. flood victims. The Federal Disaster Act of 1950 was the nation's first compre- hensive disaster relief act, and Small Business Administration disaster relief programs were also begun in the 1950s. Before the 1960s a number of single-purpose federal laws and programs protected various specific natural resources and thus indirectly helped protect the natural resources of some floodplains. For example, the creation of national parks and federal forest reserves resulted in the protection of signifi cant areas of natural floodplains. Other laws protected wildlife habitat and "I preserved open space for conservation and recreation, thus ensuring that some floodplain areas would be left in their natural states. 1960s: A Time of Change Despite the billions of dollars in federal investments in structural projects, and the demonstrated effectiveness of these measures, flood losses Previous page: Davis Dam, Colorado River, near Bull- and disaster relief costs continued to rise because of unwise occupancy and head City, Arzow. use of the nation's floodplains. Thus, broader approaches were studied and 24 applied, including zoning and other land use regulation, flood forecasting, federal flood insurance, relocation of property, and alternative water storage techniques. Major steps were taken to redefine federal policy Section 206 of the Flood Control Act of 1960 authorized the Corps to provide technical services and planning assistance to communities for wise use of the floodplain and for ameliorating the flood hazard. The Corps began producing maps and floodplain information reports describing a community's flood hazard from a broader perspective. The President's water policy statement of 1962 estab- lished policies and procedures for comprehensive river basin plans. The Water Resources Planning Act of 1965 created the U.S. Water Resources Council and authorized federal-state river basin commissions for comprehensive basin planning. House Document 465, the report of a Bureau of the Budget Task Force on Federal Flood Control Policy, advocated a broader perspective on flood control within the context of floodplain development and use. Executive Order 11296, Flood Hazard Evaluation, directed all federal agencies to evaluate the flood hazard before undertaking federally financed or supported actions and to play a lead role in preventing uneconomic use and development of flood- plains. Fifteen states, most notably Wisconsin and Minnesota, adopted flood- plain management programs, some of them providing for strict regulation. Local governments also began trying to deal with the hazard in a more com- prehensive way, usually with assistance from a state or federal agency such as the Tennessee Valley Authority. HISTORY OF A UNIFIED NATIONAL PROGRAM FOR FLOODPLAIN MANAGEMENT House Document 465, A UnfiLed Nm@nal Progranifor Managing Flood Losses, was submitted to Congress by President Lyndon Johnson in August 1966. It had been prepared by the Task Force on Flood Control Policy at the administration's request in an attempt to slow the mounting national toll of flood losses, unchecked by over $7 billion in national investments in flood control projects since 1936. House Document 465 recognized the need for a unified approach and for new planning measures, and made 16 recommendations for federal agencya'ction to begin implementation of a program- including new legislation, specific studies, and new programs for collecting and disseminating flood-related information. A Unified National Program, 1976 In response to a 1968 Bureau of theBudget request for a repon pursuant to a directive in Section 1302(c), of the National Flood Insurance Act, and to a 1975 U.S. General Accounting Office report criticizing House Document 465 and Execu- tive Order 11296, the U.S. Water Resources Council submitted to the President the UnifLed National Programfor Flood- pt2in Monagernent in 1976. This revision, whose tide change reflected A significant recognition that more than flood losses were involved, established a more detailed framework for the program, described the greatly changed context in which it would be implemented (numerous changes in flood-related federal programs had taken place), and added manage- ment strategies and tools for federal, state, and local decisionmakers to use. The report focused on the need for improved coordination, which was cited as the "weakest component of current management efforts." 1979 Revisions to a Unified National Program Although the 1976 Unified National Program made a significant step forward in floodplain management, its very effectiveness made it quickly dated. Several executive level actions-President Carter's floodplain management policy articulated in 1977, Executive Orders 11988 and 11990, and the President's 1978 water policy initiatives-were soon taken, making the 1976 version obsolete. The Federal Interagency Floodplain Management Task Force updated and refined the Unified National Program in a report submitted by the Water Resources Council to the President in 1979. This revision incorporated federal concern with the "natural and beneficial values" of floodplains, responded to the President's policy directives, expanded the strategies (adding two: restoration of natural values and preservation of natural values), tools, and conceptual framework accordingly, and emphasized the insufficient awareness of alterna- tive strategies due to "lack of adequate technical and procedural information to guide floodplain decision-makers." 1986 Revisions to a Unified National Program In 1982, the Office of Management and the Budget assigned responsibility for the Unified National Program to the Federal Emergency Management Agency, which assumed chair of the Interagency Task Force. The Task Force sub- mitted an updated Unified National Program in 1986, noting that the 1979 report had become "dated by the relative success and changes in federal programs and by the strengthening of floodplain management capability at the state and local levels." These changes included the use of federal interagency hazard mitigation teams, passage of the 1982 Coastal Barrier Resources Act restricting federal expenditures that might encourage development of coastal barriers along the Atlantic and Gulf coasts, and completion of two major National Science Foundation studies on flood haz- ard mitigation. The report included more explicit recommendations for the federal role in supporting state and local initiatives. 75 Two major pieces of legislation rounded out the change in federal policy. In 1969 the National Environmental Policy Act provided for consideration of environmental values in all federal and federally supported actions, making it possible to recognize the multiple values of floodplains. The National Flood Insurance Act of 1968 made federally subsidized flood insurance available to participating communities, contingent upon their implementing nonstructural flood loss reduction measures embodied in local floodplain management regulations. 1970s: The Environmental Decade During the 1970s numerous state and federal environmental laws and programs and water resources initiatives began to decentralize water manage- ment and bring about a much broader perspective on floodplains. Numerous federal programs took shape for water quality management, pollution and erosion control, watershed management, and protection of groundwater, aquifers, inland and coastal wetlands, barrier islands, and specific habitats. Complementary legislation was passed by many states, requiring environ- mental quality review and impact assessments at state and local levels. During this decade, changes were made in the National Flood Insurance Program; a proposal for a Unified National Program for Floodplain Manage- ment was issued and later updated; and executive orders on floodplain man- agement and protection of wetlands were issued, making disaster relief contin- gent upon mitigation action and requiring the consideration of nonstructural measures in federal flood control projects. State and local involvement in floodplain management increased with the appointment of National Flood Insurance Program coordinators in all states, the adoption by more states of regulatory programs, increases in state budgets for floodplain management, and the adoption of resource conservation legisla- tion. About 17,000 communities adopted floodplain management regulations, and many adopted regulations to manage other local resources, such as wet- -9, lands and coastal areas. d 1980s: Continuing Evolution More attention was given to implementing policies and programs for managing floodplains during the 1980s. The federal government took the role of coordinator and provider of technical assistance, while state and local gov- ernments gradually fashioned floodplain management strategies appropriate to their own jurisdictions. Interagency agreements were crafted to establish common policy on nonstructural measures and to evaluate floodplain manage- ment options after disasters. The Coastal Barrier Resources Act of 1982 estab- Coastal management in the Unzied States is shaped by the lished a policy of nondevelopment and avoidance of high hazard areas by pro- federal Coastal Zone Management Act of 1972 and the hibiting new federal expenditures on certain undeveloped coastal barriers. Coastal Barrier Resources Act of 1982. The former author- The natural and cultural resources of floodplains received more protec- ized federal grants to states for development and implemen- tation of coastal management programs for water and land tion through multipurpose, often federally supported projects for open space, resources in coastal zones. As amended, the Act incor- recreation, urban renewal, greenbelt, and waterfront redevelopment. porates both Aod loss reduction and protection of natural State and local officials became even more involved in hazard mitiga- resources into program goals. The latter legislation estab- tion planning with the implementation of requirements for planning after all lished a system of largeo undeveloped coastal barriers Presidentially declared disasters and with participation in interagency hazard along the Atlantic and Gu@f coasts in which federalo sub- sidized development is restricted. mitigation teams. Sand dunes, Santa Rosa Island, Fkrzda. The Management Framework Like any activity, floodplain management is carried out within a structure of legislative, administrative, economic, and judicial opportunities and con- straints. The way in which floodplain lands and waters are handled, decisions are made and actions taken-whether by the U.S. Congress or by a single homeowner in a floodprone area-depends upon the relevant law, the policies rz and programs of government agencies, funding, public interest and opinion, and the availability of needed information. The framework for floodplain management has been strengthened significantly since the 1960s. Before then, flood loss reduction was largely dependent upon flood control works and fed- eral actions; at the same time, a number of single-purpose federal laws and programs protected various natural resources, only indirectly addressing pro- 26 Strategies and Tools for Floodplain Management Strategy A. Modify Susceptibility to Flood Damage and Disruption 1. FloodpIain Regulations a) @ State regulations for flood hazard areas b) Local regulations for flood hazard areas 1) Zoning 2) Subdivision regulations 3) Building codes 4) Housing codes 5) Sanitary and well codes 6) Other regulatory tools 2. Development and Redevelopment Policies a) Design and location of services and utilities b) Land rights, acquisition, and open space use c) Redevelopment d) Permanent evacuation 3. Disaster Preparedness 4. Disaster Assistance 5. Floodproofing Flood Forecasting and Waiming Systems and Emergency Plans Strategy B. Modify Flooding 1. Dams and Reservoirs 2. Dikes, Levees, and Floodwalls 3. Channel Alterations 4. High Flow Diversions 5. Land Treatment Measures 6. On-site Detention Measures Strategy C. Modify the Impact of Flooding on Individuals and the Community 1. Information and Education 2. Flood Insurance 3. Tax Adjustments 4. Flood Emergency Measures 5. Postflood Recovery Strategy D. Restore and Preserve'the Natural and Cultural Resources of Floodplains 1. Floodplain, Wetland, Coastal Barrier Resources Regulations a) Federal regulations b) State regulations c) Local regulations (1) Zoning (2) Subdivision regulations (3) Building codes (4) Housing codes (5) Sanitary and well codes (6) Other regulations 2. Development and Redevelopment Policies a) Design and location of services and utilities b) Land rights, acquisition, and open space c) Redevelopment d) Permanent evacuation 3. Information and Education 4. Tax Adjustments 5. Administrative Measures tection of the natural and cultural resources of floodplain. Today's floodplain GENERAL PRINCIPLES FOR management framework is a product of planned initiatives, evolved methods, FLOODPLAIN MANAGEMENT and fortuitous circumstances. Many aspects of the framework developed The federal government has a fimdamental interest independently and then were incorporated for the common purpose. Many in how the nation's floodplains are managed, but the were intended at the outset to complement each other. Many apply to flood- basic responsibiliyfor regulatingfloodplains lies plains only incidentally but nevertheless serve an important function. with the state and local governments. The idea of a unified national program for reducing flood losses was 9 Floodblains must be considered in the context of first set out in House Document 465 and has been refined and expanded total community, regional, and national planning since to produce A Unjit-ed Natioi@ Programfor Floodplain Management. It estab- and management lishes as a basic national goal the wise use of floodplains; sets forth the con- e Flood loss reduction should be viewed in the larger ceptual framework of a multiobjective approach to use of the nation's flood- context offloodplain management, rather than as an plains, including flood loss reduction and natural values protection; identifies objective in itseff implementing strategies and tools; and recognizes the respective roles of each 9 Soundfloodplain management embodies several level of government and the private sector in the decisionmaking process. aspects: There are four main strategies for reducing floodplain losses. They are 0 goals (wise use, conservation, and development described in detail in the Unified National Program documents. Each strategy Of resources), can be carried out by using one or more specified "tools" -activities under- * Objectives (economic efficiincy, environmental taken by governments, individuals, or the private sector that have an impact quality, and social well-being),- on floodplain management: 0 consideration offuture needs and the role of the 0 Modify susceptibility to flood damage and disruption. floodblain; 0 Modify flooding. 0 evaluation of alternative strategiesfor alleviat- 0 Modify the impact of flooding on individuals and the community. ingflood losses,- 0 accountingfor benefits and costs and inter- 0 Restore and preserve the natural and cultural resources of floodplains. related impacts offloodplain management actions,- At all levels of government and within the private sector, the tools and motivation of decisionmakers; strategies for floodplain management take various forms, including compo- coordination of agencies at all Levelsfor all nents of broader initiatives, legislation, and policy directives in water resources aspects offloodplain management; and management, emergency management, environmental protection, and proj- 0 evaluation through continuous monitoring and ects for community development and redevelopment. Federal, state, and local reporting to the public. programs and private efforts to manage the natural and cultural resources of floodplains are usually focused on the particular resource or activity that hap- Source: A Unified National Program for Floodplain pens to occur on the floodplain rather than on the floodplain itself Management, 1976 The Federal Government At the federal level, flood loss reduction is accomplished through a network of laws, executive orders and directives, administrative regulations, interagency actions, and agency policies and programs. These components of the framework address various aspects of floodplain management, includ- ing insurance, land use, disaster preparedness and relief, information and education, warning systems, and structural flood control. At least 25 subdivi- sions of 12 departments and agencies have significant responsibility for some aspect of floodplain management. The water resources values of floodplains are managed through pro- grams for water quality, pollution control, watershed management, erosion control, and groundwater and aquifer protection. Restoration and preserva- tion of the living resources of floodplains have been addressed in multiobjec- tive federal programs or activities aimed at protecting inland or coastal wet- lands or barrier islands. Other federal programs have been specifically directed at protecting habitat. Cultural resources have been protected through a variety of federally supported programs for open space, recreation, urban renewal, waterfront redevelopment, and historic preservation. State Government State activities for floodplain management have responded to and often paralleled federal activities. States administer locally adopted and enforced floodplain management regulations pursuant to the National Flood Insurance Program. All coastal states have some type of permitting program for devel- opment activities below mean high water and most coastal and Great Lakes states have federally approved coastal management programs. Every state has a multihazard emergency operations plan that covers floods. All coastal states and some inland states have wetland protection programs of some sort which 78 include mapping, permitting, and protection. SOME COMPONENTS OF THE FEDERAL FRAMEWORK FOR FLOODPLAIN MANAGEMENT the Clean Water Act of 1972 0 Coastal Barrier Resources Act (1982) 0 Coastal Zone Management Act of 1972 The Dam Safety Act (1986) 0 The Disaster Relief Act of 1974 0 The Disaster Relief and Emergency Assistance Amend- ments of 1988 0 The Emergency Wetlands Resources Act of 1986 0 The Endangered Species Act of 1973 0 Executive -'Order 12127 (1979) 0 Executive Order 12148 (1977) o Executive Order 11296 (1966) 0 Executive Order 11988 (1977) Executive Order .11,990, 'Protection of Wetlands 0 The Federal Crop Insurance Act (1980) 0 The Federal Insecticide, Jungicide, and Rodenticide Act a Federal Interagency Floodplain Management Task Force established 1975 * The Federal Land Policy and Management Act of 1976 0 Fish and Wildlife Coordination Act of 1958 * The Flood Disaster Protection Act of 1973 0 The Food Security Act of 1985 * House Document 465, A UniftdNational Prograinfor Managing -'Flood Losses - The Housing Act of 1961 0 The Housing-and Urban Development Act of 1969 0 The Housing and Corn- munity Development Act of 1977 0 The Housing and Community Development Act of 1987 0 The Land and Water Oonser-Vatibn Fund,Act 1964) 4@ The Nationa I Dam Insi)ecti6n A:ct,of,1072 0 The National Environmental Policy Act @1969) eThe'National Flood Insurance Act (1968) 0 The National Forest Management Act of 1976 0 The National ''Historic Preservation Act (1966) @@ The North American Waterfowl Management Plan (1986) 0 OMB Memorandum, N6nstruttural Flood Protection Measures and Flood Disaster Recovery" (1980) 0 The Omnibus Budget Reconcili- ation Act of 1981 The Reservoir Salvage Act of 19,60 0 The Safe Drinking Water Act of 1974 0 The Soil and Water Resources Cons6rvation.Act of 1977 *The Tax RefornrAct of 1986 0 United States-Mexico Boundary Treaty of Nc@vem- ber 23,,1970,o The Water 'Bank Act (1970) 0 Water Pollution Control Act Amendments of 1972 a The Water Quality ,Act of 1987 0 The Water'Resources Development Act of 1974@9 The Water Resources Development Act of 1986 0 The Water Resources Development Act of 1990 0 Water Resources Planning Act of 1965 0 The Watershed Protection and Flood Prevent-ion Act of 1954 The Wild, and,Scenic Rivers Act of-1968 0 Flood Control Act of 1917 0 Rivers and Harbors,Act of 1930 a Flood Control Act of 1936 Several states have adopted their own statewide floodplain management regulations, and in some states executive orders compel state agencies to con- sider flood hazards before carrying out their activities. Several states have adopted environmental policy acts that require analysis of the impacts of proposed state and local actions on natural resources, including those of the floodplain. Every state has an agency involved in planning, funding, or spon- soring structural flood control projects. Floodplain management is further accomplished through state-level regulatory and nonreg-ulatory programs directed at wetlands, dune protection, restoration and protection of living resources and natural areas, mapping, flood conveyance and storage, dam safety, pollution control, natural crops, groundwater supply, wildlife habitat, historic preservation, recreation, and shoreline management. THEIDNDR Local Government In 1987 the United Nations General Assembly &clared 1990 to 2000 AD as the International The adoption and enforcement of local floodplain regulations is now Decade for Natural Disaster Reduction (IDADR). widespread because of the National Flood Insurance Program. Many local It is antz@cipated that this assessment will provz& zoning and subdivision regulations protect the natural and cultural resources useful input to the United States program for of floodplains through shoreline setbacks, density limits, historic preservation the Decade. guidelines, or specification of compatible uses. Local governments are almost exclusively responsible for local drainage and stormwater management. Many localities participate as cosponsors of structural projects, providing a small financial contribution to the cost of the works. Some localities have coastal management programs within a state framework, and some states provide for local application of state controls, usually established under legislation geared toward multiple goals like protection of wildlife and sensitive shoreland areas, or erosion control. Some communities have developed multihazard emergency preparedness or operations plans. Regional Entities Regional entities can be extremely effective in managing floodplains, whose boundaries typically do not conform to traditional governmental juris- dictions. Special districts are the most numerous and fastest-growing type of governmental entity in the country; nearly one-quarter of them have natural resource functions-soil and water conservation, drainage and flood control, and sewerage. The nation's 3,000 counties also have floodplain management functions, including storm drainage, land acquisition, flash flood warning, emergency response, land use planning, and building regulation (usually of unincorporated areas). Nearly 3,000 conservation districts exist, covering more 79 than 97% of the country. They provide planning and technical assistance to SELECTED PROFESSIONAL AND individual landowners for controlling soil erosion and water pollution, and NONPROFIT ORGANIZATIONS ACTIVE they implement swampbuster, wetland restoration, and erosion reduction IN FLOODPLAIN MANAGEMENT portions of the Food, Agricultural, Conservation, and Trade Act of 1990. American Institute of Architects The Private Sector American Land Resource Association American Littoral Society Besides undertaking basic and applied research on floodplain manage- American Planning Association ment, academic institutions also provide education in the field, although so American Rivers Conservation Council far no university offers a program of study specializing in floodplain manage- American Socieo of Civil Engineers ment. Many states have Water Resources Research Institutes, as authorized American Water Resources Association by the Water Resources Act of 1964. Association of Conservation Engineers Over 700 national and local land trusts exist throughout the nation. Association of State Dam Safety Officials Most are nonprofit organizations that receive land, either through donations Association of State Floodplain Managers or purchase, and manage it as open space or for historic purposes. Association of State River Managers There are a large number of professional and nonprofit organizations Association of State Wetland Managers The Coastal Socieo involved in floodplain management. Most are national in scope and accom- Jr Coastal Conservation Association plish their objectives through meetings, publications, lobbying, and fostering Coastal States Organization professional communication. The number of private conservation and water- Connecticut River Watershed Council shed organizations is even larger. Usually nonprofit with a broad public The Conservation Foundation membership, they are typically directly involved in environmental issues with Conservation Law Foundation of New England flood loss reduction as an indirect goal or benefit. These citizen-based groups Council of State Governments serve a tremendous public education function, are largely unaffected by parti- Environmental Defense Fund san politics, and can usually respond to an issue more rapidly than govern- The Environmental Law Institute ment agencies. Environmental Policy Institute Individuals and for-profit corporations have become more involved in Freshwater Foundation Friends of the Earth floodplain management since the 1960s, helping develop floodproofing tech- Friends of the River niques and materials, automated flood warning systems, geographic informa- Land Trust Alliance tion systems, remote sensing techniques, and computerized information League of Conservation Voters management. National Association of Conservation Districts National Association of Counties National Association of Home Builders National Association of State Recreation Planners National Association of Urban Flood Manage- ment Agencies Modifying Susceptibility to National Audubon Society National Centerfor Urban Environmental Damages and Disruption Studies National Emergency Management Association Modifying susceptibility to flood damage and disruption is the floodplain National Fish and Wildlzfe Foundation management strategy of avoiding dangerous, uneconomic, undesirable, or National League of Cities National Organization for River Sports unwise use of the floodplain. The tools used to implement this strategy are National Recreation and Parks Association regulations; development and redevelopment policies; disaster preparedness; National Traits Coalition floodproofing and elevation; and flood forecasting, warning systems, and National Trustfor Historic Preservation emergency plans. National Water Resources Association National Waterways Conference Regulations National Wetlands Technical Council National Wildlife Federation Regulations have a potentially greater impact on flood loss reduction The Natural Areas Association than any other single floodplain management tool and have been widely used Natural Resources Defense Council over the last 15-20 years. Development that conforms to regulations is less New England Natural Resources Center prone to flood damage than pre-existing development. North American Lake Management Society Regulation is largely a local government responsibility, but throughout The Oceanic Society much of the country there is still widespread resistance to any type of land The River Conservation Fund use regulation and concern among jurisdictions that it will be ruled an uncon- Save the Dunes Council stitutional "taking" of private property. Effective enforcement often requires Sierra Club more training, personnel, and financial resources than many communities can Socieo for Range Management provide. Regulations cannot provide full protection; they have a limited impact Soil and Water Conservation Sociey on existing buildings and infrastructure already subject to flooding, and they do The Sounds Conservancy The Trust for Public Land not prevent development in floodplains. In addition, most floodplain regulations Urban Land Institute do little to protect the natural resources of floodplains. In fact, to the extent Wetlands for Wildlzfe that floodplain regulations allow development in floodplains- even though it The Wilderness Sociey may not be subject to damage-they can contribute to the loss of natural and Wildlife Management Institute cultural resources. On the other hand, current regulations do provide a de I facto prohibition on development in wetlands. 30 Academic Institutions Engaged in Natural Hazards and Emergency Management Research and Education Arizona State University, Office of Hazard Studies 0 Charleston Southern University, Earthquake Educa- tion Center 0 Brown University, Alan Shawn Feinstein World Hunger Program 0 Clark University, Center for Technology, Environment, and Development 0 Colorado State University, Hazards Assessment Labora- tory 0 Cornell University, Cornell Institute for Social and Economic Research/Program in Urban and Regional Studies 0 Memphis State University, Center for Earthquake Research and Information * New York Medical College, Center for Psychological Response in Disaster Emergencies a New York University, Industrial Crisis Institute 0 State University of New York at Buffalo, National Center for Earthquake En- gineering Research 0 Texas A&M University, Hazard Reduction and Recovery,Center 0 Texas Tech Univer- sity, Institute for Disaster Research,,Wind Engineering Research Center 0 University of Arizona, Office of Arid Lands Studies and Arid Lands Information Center 0 University of California, National Information Service for Earthquake Engineering * University of California, California Earthquake Education Project and Chemical Education for Public Understanding Project 9 University of Central Florida, Florida Sinkhole Research Institute 0 University of Colorado, Natural Hazards Research and Applications Information Center 0 University of Colorado, U.S. World Data Center for Glaciology, National Snow and Ice Data Center * University of Delaware, Disaster Research Center 0 University of Hawaii,'. Pacific Islands Develop- ment Programi Disaster Pre aredness and Rehabilitation Project 0 University of Maryland-Baltimore 'p County, Emergency Health Services Program 0 University of Massachusetts,, Land and Water Policy Center @ University of North Carolina, Center for Urban and Regional, Studies 0 University of North Texas, mergency Administration and-Planning Degree Program,*, Uriversity.of Pennsylvania, The Wharton School, Risk and Decision Processes@'Ccnter 9 Universitylof Pittsburgh, Center for Social and Urban Research 0 University of Wisconsin Eitension, Disaster Management Center Source: Natural Hazards Research and Applications Information Cc nt er The most widespread floodplain regulations are the minimum require- Average Losses per 1,000 Flood ments of the National Flood Insurance Program, which must be enacted and Insurance Policies on Unregulated enforced by communities participating in the program. The minimum regula- versus Regulated Structures, 1978-88 tions vary depending upon the risk studies and mapping that have been done 26 in the community, but include 24 Structures Built 22 Bell tion � permitting for all proposed new development; 20 � reviewing subdivision proposals to assure that they will minimize flood D. 18 damage; E 4'5 16 14- 0 � anchoring and floodproofing structures to be built in known floodprone -0 12 areas; -0 Z5 to E a 8 Structures Built � safeguarding new water and sewage systems and utility lines from Z 6 After Regulation flooding; and 4- � enforcing risk zone, base flood elevation, and floodway requirements 2 after the flood insurance map for the area becomes effective. 0 Source: FEMA/FIA There are numerous performance and prescribed standards applicable to each of the zones on flood insurance maps. The Federal Insurance Admin- istration has several programs to help states and communities adopt and com- ply with the regulations. Other federal agencies provide technical and plan- ENFORCING LAND USE ning assistance and support. REGULATIONS IN MAINE Since the 1960s the number of state and local governments exercising In 1983 the Maine legislature enacted "Ruk 80K" regulatory authority over floodplain uses has increased markedly, and the vari- to allow less expensive andfaster enforcenzent of local ety of regulatory approaches has expanded. A given state may directly regulate land use regulations. Once local code enforcenzent the flood hazard area, set standards for local application, or regulate the flood officials are trained, they can take a violation directo hazard area as part of a broader resource protection and management pro- to the district court without an attorney. Procedures gram. To meet these requirements, local governments adopt specific flood- arefolkwed that are lessforinal than usual but do not sacr2fice the defendant's due process rights. plain management or stormwater management ordinances and incorporate The court can levy afine and order abatenient Of floodplain management provisions into zoning and subdivision regulations, the violation. housing and building codes, and resource protection regulations. The number of communities with regulatory requirements more stringent than those of the National Flood Insurance Program is unknown, but clearly is in the thousands. Development and Redevelopment Policies THE SOUTH CAROLINA Federal, state, and local governments all have established programs, poli- BEACHFRONT MANAGEMENT ACT cies, and directives to avoid inappropriate development and redevelopment of The South Carolina Beachfront Management Act the floodplain. establishes a "no construction" zone beginning at the Federal policies relating to the design and location of services and utilities crest of the actual or theoretical dune line and extend- (roads, bridges, and sewer lines, etc.) in floodprone areas include the National ing landward 20feet or 40 times the average annual Environmental Policy Act, Executive Order 11988, and the Coastal Barrier rate of erosion, whichever is greater. The legislature Resources Act. All of these either restrict federal participation in development anticipated that the Act would result in the gradual elimination of structures built too close to the ocean in floodprone areas or require careful review of the impacts on the floodplain and hence subject to damage or destruction from of proposed federal or federally supported activities. hurricanes and other coastal storms. Several states have issued executive orders or other directives compar- able to the federal ones, and every state now has a statute or executive order to govern construction of state projects, such as prisons and universities, that are exempt from local regulations. All coastal states have policies on develop- ment in coastal flood hazard areas. Some states have more stringent flood loss reduction standards for roads and bridges than those of the federal aid system. In some cases, the only way to preclude future uses incompatible with the flood risk is to permanently evacuate a portion of a floodplain and to obtain full title or easements on its development rights. Although this process (called "acquisition") is expensive, the long-term benefits in reduced flood- plain losses, protection of natural resources, and public use of the land, may make it worthwhile. Most redevelopment relating to flood loss reduction occurs after one or more major floods. Usually a control structure is built to protect what devel- opment remains, and a temporary moratorium is imposed to allow evaluation and planning. Unfortunately, legislative and regulatory requirements often encourage a quick return to the preflood status quo, wasting opportunities to mitigate and revitalize the area. Disaster Preparedness Disaster preparedness encompasses plans for mitigation, warning, and emergency operations; training; public information activities; exercises to test disaster preparedness plans; readiness evaluations; research; review and coor- dination of disaster preparedness plans and programs; and postdisaster evalu- ations. Individual preparedness is important but severely underutilized. Pre- paredness plans often are developed in concert with flood forecast, warning, and emergency plans. There are several federal programs for disaster pre- paredness, and every state has an integrated emergency management plan and an agency responsible for preparing for floods. Each Gulf and Atlantic SOME FEDERAL PROGRAMS FOR DISASTER PREPAREDNESS Under the authority of Section 201(d) of the Disaster Relief Act of 1974, the Federal Emergency Management Agency provides, up to 50 To matching grants to help states develop and improve state and local plans for preparedness and mitigation. Interagency flood hazard mitigation teams are formed after each Presidentially declared flood disaster to offer technical assistance to communities and states and to identify mitigation measures that may be implemented in the affected areas. 0 Under Section 409 of the Act, any jurisdiction receiving federal disaster assistance must prepare a hazard mitiga- tion plan within 180 daysof the declaration; future federal assistance may be curtailed if such a plan is not filed. The Federal Emergency Management Agency, the U.S. Army Corps of Engineers, and the National Weather Serv- ice have formed a program of comprehensive hurricane evacuation planning in association with Gulf and Atlantic states. The NWS develops the SLOSH (Sea, Lake, and Overland Surge from Hurricanes) model for each coastal basin, and FENIA funds the running of the models by the NWS's National Hurricane Center to predict storm directions, speeds, and intensities. Evacuation plans are prepared from the studies. Th 'eir value was proved during Hurricane Hugo in 1989, when hundreds of thousands of people were evacuated and loss of life was kept to a minimum. � The Federal Emergency Management Agency provides grants to states to conduct hazard mitigation projects. � The Federal Energy Regulatory Commission requires emergency action plans at its licensed projects and periodi- caily holds in-depth exercises to test the plans and the licensee's coordination of responsibilities with the appropriate state and local disaster agencies. The Soil Conservation Service has done flood audits of structures in the floodplain of the Yantic River in Norwich, and the Quinnipiac River in Southington, Connecticut, to complement the response to flood warnings. 0 The U.S. Army Corps of Engineers conducts technical evaluations to determine what types of warning systems and 32 preparedness plans are appropriate for certain areas. coast state has a hurricane preparedness plan completed or underway. Many localities also have emergency management plans, but relatively few have LYCOMING COUNTY'S EARLY detailed plans specifically for floods, and even fewer have plans for mitigation WARNING SYSTEM after a flood. This is probably due to lack of expertise and funding to develop Lycoming County, Pennsylvania, lies almost entire@ such plans, the hope that the flood problems will be taken care of through within the drainage area of the West Branch of the some structural measures, and the expectation of receiving federal disaster Susquehanna River and contains close to 2,200 miles assistance when the flood does occur. of streams. Most of the county's people live on or near the river. After major flooding from Hurricanes Flood Forecasting, Warning, and Emergency Plans Agnes in 1972 and Eloise in 1975, a se@f-help early Warning systems and accompanying emergency response have long warni .ng system was developed with an initial been recognized as effective ways to save lives and reduce flood damages in investment of $500. With the help of the National both riverine and coastal floodprone areas. The joint hurricane evacuation Weather Service, forecasting procedures were estab- lishedfor each watershed within the county, and the study is a good example of this. As the cost of the required equipment con- system was put into operation within three months. tinues to decrease, more and more state and local governments are funding Over 100 volunteer observers were recruited and the development of flood warning systems and emergency plans. trained to observe and monitor stream gages and The National Weather Service conducts research, provides specific make reports to a stream coordinator The coordina- flood forecast and warning services to over 3,100 communities, and works tor assembles the data for a watershed and conveys it with many of the 900 communities that have local warning systems. The to a system coordinator. With the help of expert per- Corps, the Tennessee Valley Authority, and the Bureau of Reclamation collect sonnel, the d2la is evaluated and a determination of hydrometeorological data and prepare operational forecasts, often in coopera- expectedflooding and appropriate response is made. tion with the National Weather Service, for their flood control structures. The Over the last 10 years improvements to the system U.S. Geological Survey collects streamflow and other data that can be used have been made. To assure adequate backupfor d2t4a for flood forecasting. transmission, the county provided National Oceanic About half of the states are involved in flood warning, including coop- and Atmospheric Administration weather radios to eration in IFLOWS (the Integrated Flood Observing and Warning System) the volunteer observers, and NWS distributed base in Appalachia and installation of automated data collection equipment. Some station radios to the stream coordinators. In addi- large urban communities have included forecasting and preparedness planning tion, a system of 10 automated rain gages and 4 automated stream alarm devices was installed to in their operations for years, participated in regional warning systems, or have supplement the manual d2ta collection. developed their own systems. University and private research has contributed substantially to the knowledge about and design of warning systems, disaster response, and sys- tem effectiveness. The private sector is vital to the design, installation, opera- tion, maintenance, and modification of local flood warning systems. In many instances, industries have cooperated in the installation and operation of flood warning systems and reduced their own flood losses. Floodproofing and Elevation Floodproofing is the use of permanent, contingent, or emergency tech- niques to either prevent flood waters from entering buildings or to minimize the damages from water that does get in. Some of the techniques involve using water-tight seals, closures or barriers; using water-resistant materials; and temporarily relocating the contents of a building. Elevating a structure means raising it on fill, piers, or pilings so that it is above expected flood Examples of Retrofitting levels. Most new floodplain structures are now designed to incorporate flood- proofing and/or elevation, primarily because it is required by the regulations of all National Flood Insurance Program communities. There are millions Reloc-tion: Moving a building to high ground, of existing floodprone homes to which floodproofing could be applied retro- above flood levels. actively ("retrofitted"), but this technique is not yet routinely used. One Elevation; Raising a building so that flood waters obstacle has been that flood insurance rates stay the same when a residence will go under it. is retrofitted; the new Community Rating System of the National Flood Insurance Program should help remove that disincentive. Floodproofing is probably the tool most widely used by the private sector Floodwalls: Building a wall of concrete or earth to keep flood waters from reaching a building. with only limited government assistance. Many of the early floodproofing tech- niques were developed by architects, engineers, and building contractors as Dry Floodproofing: Making building walls they worked with individual property owners, especially on small commercial wat might and sealing openings so flood waters buildings and industrial facilities. The American Institute of Architects, the cancot enter. National Association of Homebuilders, university researchers, and private engi- neering firms have conducted considerable research on and developed techni- Wet Floodproofing: Altering a building to cal information about floodproofing. The private sector is also the source of 44 minimice damage when flood waters enter. many floodproofing products, such as vinyl sheathing, devices to prevent sewer backflow, substitutes for sand bags, equipment for filling sand bags, and flood Source: Floodproof Retrofitting: Homeowner Self-Piolective L!Aavi@, shields to temporarily seal windows, doors, and other openings. Shirley Bradway Laska, 1991 33 FLOODPROOFING AND THE CORPS In the early 1960s the Tennessee Valley Authorio and the US. Army Corps of Engineers jointo pro- duced thefirst comprehensive report on fioodproofing. In 1972, afterfurther review and evaluation of different techniques, the Corps released Floodproof- P ing Regulations, which has since been incorpo- rated into or recommended by all the major regional building codes and many of the state and local codes. The Corps routinely evaluates the potentialfor using floodproofing in all its project feasibility studies. It also provides technical assistance to local commu nities and is involved in several projects to J70odproof large numbers of homes in communities with chronic KY, flood problems. One floodoroofing technique is to elevate a structure so that flood waters can pass beneath. Sebastien Roy Elementary School, Verret, Louisiana. Most states distribute information about floodproofing and provide tech- FLOODPROOFING IN ILLINOIS nical assistance to individuals and groups of property owners. Several states Afterfloodf in Illinois in 1982, 1985, 1986, and have promoted floodproofing by publishing technical manuals, helping locali- 1987, the state provided technical assistance on flood- ties obtain funding, holding seminars for industry and individual owners, proofing to victims who visited the local Disaster establishing loan programs, and cooperating with disaster assistance centers Assistance Centers. Over W of the flood victims so that victims can begin to retrofit immediately. Local governments have eventually altered their houses andloryards to protect floodproofed individual structures. A few communities have provided their themselves from future flooding. The average own funding for larger projects, and others have provided technical and homeowner implemented three different floodproofing financial assistance to local businesses and residences. measures. The median costs rangedfrom $42for a standpipe or sewer drain plug to $2,350for sewer backup valves; most cost between 1200 and $600. Most of thefloodproofing measures were installed within two months after thejZood. Those who were Modifying Flooding flooded again in the 1987floodsfound that their floodbroofing measures were general@y effective. Modifying flooding is a floodplain management strategy of using structural means to alter the flood itself Structural measures-dams, reservoirs, dikes, levees, floodwalls, channel alterations, high flow diversions, spillways, land treatment measures, shoreline protection works, and stormwater management facilities-permit deliberate changes in the volume of runoff, peak stage of the flood, time of rise and duration of flood waters, location of flooding, extent of area flooded, and velocity and depth of flood waters. The effectiveness of these measures for protecting property and saving lives has been well demonstrated. Flood control projects have saved billions of dollars in property damage and protected hundreds of thousands of people from anxiety, injury, and death. Throughout the second half of this century, the number and size of structural flood control projects have been decreasing. High construction costs coupled with increased cost-sharing requirements for nonfederal sponsors of projects have made some structures unaffordable. Structural measures also have been criticized for destroying riparian habitat, scenic values, and water quality; creating a false sense of security; resulting in eventual loss of flood storage capacity due to sedimentation; and inducing development in flood- plains. These criticisms have been coupled with greater recognition that humans should attempt to adjust to floods and not just try to control them. It appears likely that the rate of construction of new flood control projects may hold steady or decrease slightly and that relatively few large flood control structures will be built in the future. Local and private construction of smaller flood control projects is certain to continue and may even increase. One issue that the nation must face in the coming decades is how to deal with the aging inventory of existing flood control structures. Many darns and reservoirs are nearing or even past their design lives, and the flood control 74 capacity of many reservoirs has been reduced by sedimentation. The financial Expenditures by Federal Water Resource Agencies, 1986 Agencies Federal Total $3.4 Billion Corps of Engineers (70%) TVA (1%) Jl scs (8%) Al 4@ ...... buRec (21%) Structural rmasures to directly control floodwaters have been used on virtually all seiiies-froin modifying a nzql.or river course, such as that of the Colorado, Missouri, or Tennessee, to controlling the flow of (usually) insignificant tributari&. Concrete channel and retaining wal1l, Silver Creek, Leyden Township, Illinois. U.S. Army Corps of Engineers Expenditures resources are not available to undertake all required remedial actions. One option being actively considered and already used on a limited basis by the od Control (39%) Soil Conservation Service andothers is breaching small dams that are no Billion longer functional. Investment in Flood Control The Flood Control Act of 1936 established the federal interest in control- ling floods on the nation's navigable waters and their tributaries. Under this Other (61%) Act, $310 million was authorized for carrying out flood control projects, with the Corps receiving major responsibilities for mainstern and downstream projects. The Soil Conservation Service was later assigned responsibility for flood protection on upstream watersheds. This act established the condition that federal involvement in flood control would be appropriate "if the benefits to whomsoever they may accrue are in excess of the estimated costs and if the lives and social security of the people are otherwise adversely affected." For 50 years this phrase has been the basis of efforts to analyze the benefits and costs of water resources projects. In addition to the Corps and the Soil Conservation Service, the Bureau of Reclamation and the Tennessee Valley Authority are involved in the con- struction of flood damage reduction structures. The Bureau of Reclamation has planned and constructed many large irrigation and hydropower reservoir projects in the western United States that also provide flood control, including Grand Coulee Dam, the Central Valley Project, and Hoover Dam. The Ten- nessee Valley Authority has played a role in flood control since its creation in 1933; two of its statutory purposes are "to improve navigation in the Tennes- see River and to control destructive flood waters in the Tennessee River and Mississippi River Basin." WATER RESOURCES DEVELOPMENT Between 1936 and 1975 the federal government spent about $13 billion BY THE STATES for dams and other structures. A few of the first flood control projects were 0 Florida has created Water Management Districts financed 100% by the federal government, although most required the con- that are authorized to levy ad valorem taxes to tribution of land, easements, and rights of way by state and local governments finance local waterprojects. and maintenance of the project after it was completed. Today, however, state 0 In Montana, a water development fund was and local governments and private sponsors are required to share the costs created in 1981 to make loans and grants for all of practically all flood control projects. water development purposes. State and local governments play two major roles in funding water Louisiana, Maryland, and Minnesota have resources development: constructing and operating their own projects, and recento created programs to Provide financial assis- financing their share of and maintaining the projects built for them by the tance to communities that developflood control plans. federal government. Tremendous variations exist in the extent of state and a Washington provides grants to communities to help local involvement in each role. As of 1988, 23 states provided technical maintain levees and otherfood protection projects. assistance to communities for flood control; many more states are directly involved in local structural flood projects in other ways. 35 DAMS AND THE FEDERAL GOVERNMENT The US. Army Corps of Engineers has some responsibility for five categories of dams: dams planned, designed, constructed, and operated by the Corps; dams designed and constructed by the Corps but operated and maintained by others; dams owned by other agencies in which flood control storage has been provided at federal expense; dams for which the Corps issues permits under its regulatory authority; and dams that the Corps inventoried and inspected under the National Dam Inspection Act of 1972 and the Dam Safety Act of 1986. 0 Upon its creation in 1979, the Federal Emergency Management Agency was given responsibility for coordinating dam safety The agency coordinates the national dam safety programs and reports progress to the President; chairs the Interagency Committee on Dam Safety; encourages the development and use of uniform guidelines and stan- dards; coordinates dam safety research; coordinates the development and funding of training materials; facilitates infor- mation exchange among federal and state officials; encourages the use of model state legislation and programs; and fosters preparedness, warning, and evacuation programs. The Bureau of Reclamation is the coordinating agency for dam safety within the Department of the Interior. In addition to responsibility for the safety of its own dams, it provides standards and guidelines for the safety of dams owned or operated by seven other Interior agencies. * The Tennessee Valley Authority has complete responsibility for the planning, design, construction, operation, and maintenance of its dams. The TVNs situation is unique in that it constructs its dams with its own resources, and all except one of its dams are located in a single river basin and operated and maintained for the unified development and regulation of the Tennessee River system. 0 The U.S. Department of Agriculture, in fulfilling assigned responsibilities to American agriculture, is a permitter, owner, -manager, planner, designer, constructor, financier, and grantor of dams. Most of the dams are small, but a few range up to 200 feet high. * The Soil Conservation Service has provided technical and/or financial assistance for the installation of over 25,000 dams. 0 The U.S. Forest Service owns 1,316 dams and administers permits for an additional 2,366. Most of the owned dams are designed and constructed by the Forest Service in conjunction with the management of national forests and grasslands. 0 The Farmers Home Administration, Rural Electrification Administration, and the Agricultural Research Service also serve on the U.S. Department of Agriculture's Dam Safety Committee and have some involvement with dams, but generally depend on the Soil Conservation Service for technical assistance. 9 The Federal Energy Regulatory Commission regulates and licenses nonfederal hydropower projects. The commis- sion is presently responsible for the safety of about 2,000 nonfederal hydropower dams and the Department of Energy (DOE) has asked FERC to be responsible for dam safety review on 20 DOE dams. Dams and Reservoirs Storing flood water in reservoirs can modify floods by reducing the speed at which the water flows, limiting the area flooded, and reducing and altering the timing of peak flows. However, misconceptions about or lack of understand- ing of dams can create an exaggerated sense of security. Reservoir sedimenta- tion can significantly reduce flood control capacity. Competing uses of the THE DAMAGE PREVENTED reservoir can impair flood control because those relying on the dam for recre- BY FLOOD CONTROL DAMS ation and water supply (irrigators, manufacturers and residential users) often jVo accurate number is available of the actual press for continued high pool levels, resulting in less storage space in the number of people protected bj, flood control reservoir for flood waters. In addition, most dams are designed for purposes dams. Between 1960 and 1985, Corps other than flood control, although they do have the temporary effect of flood prol'ects prevented an estimated $245 billion reduction through storage. The availability of water, power, or recreational (1985 dollars) in potential flood damages. opportunities associated with dams therefore often attracts new development Since its inception, the Tennessee Valley regardless of the flood risk or the ability of the dam to provide flood protec- Authorio multipurpose dam and reservoir sys- tion. Over time, without adequate land use regulations, encroachment onto tem has preventedflood damages that would the floodplain downstream of dams can prevent proper operation of the have amounted to nearly @3. 03 billion. These structure and increase exposure to flooding. Once signs of dam failure calculations are based on the assumption that become visible, breaching often occurs within minutes or a few hours, leaving floodplains would have been just as intensively little or no time for evacuation. The massive volume of water and its high or spar'sely developed if there were no structural velocity will cause severe damage. protection. Although this is not necessarily the case, there is no way to account for the de- More than 20 federal agencies and four independent offices and com- velopment that may have been encouraged by missions own about 4,000 'dams, have regulatory authority over 6,000 others, the presence of the dam. Likewise, it is possi- and have various other responsibilities for additional tens of thousands of non- ble that losses could be greater without dams federal dams. The number of dams of all types and sizes in the United States because development would have taken place in is unknown, but when small dams (such as for farm ponds) are included, the the reservoir area if the dam had not been total could be as high as several million. built. State regulation of dams is generally considered to have started in California after the failure of the St. Francis Dam in 1928. The California law 36 has been strengthened at least twice since then after other major dam failures or near failures, and has been used as model state legislation for the review, THE CLASSIFICATION OF DAM inspection, certification, and maintenance of nonfederal dams. As of 1989, 31 FAILURE RISK states had statutory authority to perform all of these functions, and only two Classf@ation of the risk of potential dam failure is had no statutory authority at all. The states had a collective 1989 budget for based on the severiy of Potential impact rather Man dam safety of $17,668,552. The Association of State Dam Safety Officials, the structural safety of a dam. Dams may be of very which was organized in 1984, has become a major influence in Improving sound construction but classified as "high hazard" if state regulation of dams. theirfailure, however unlikely, could result in catastrophic loss of life. Lower risk classifications Dikes, Levees, and Floodwalls include dams that pose a "significant hazard"for which failure is estimated to result in large property Dikes, including levees and floodwalls, can be thought of as dams built loss; and those that are "low hazard,"Jor which roughly parallel to a stream rather than across its channel, or parallel to the failure is expected to result in mminial property loss. shorelines of lakes, oceans, and other water bodies. Levees are generally con- Thefailure of several dams during the 1970s led to the evaluation and repair of numerous unsafe dams in the United States. Nt 71, An estimated 25,000 miles of levees andjloo&vak@ have been built nationwide. They can be very effective in reducing_17ood losses, although areas behind levees andfloo&valls may risk greater than normalAod d2mage. Floo&vall, Waterloo, Iowa. structed of earth, floodwalls of masonry or steel. Levees were probably the first structures built for flood control by European immigrants to North America. Thelfirst levee in the Mississippi Valley was constructed at New Orleans in 1717. Levees are the most common type of flood control works. Although they can-be effective in reducing flood losses, a large percentage of private or locally built levees and floodwalls provide a low level of protection suitable only for agricultural purposes or are poorly designed and maintained. Levee or floodwall overtopping or failure is involved in approximately one-third of all flood disasters. Areas behind levees and floodwalls may be at risk of greater than normal flood damage for several reasons. Many floodplain residents in those areas believe that they are protected from floods and do not think it necessary to LEVEES IN THE UNITED STATES take proper precautions. Development may also continue or accelerate based About 1, 000 communities (5.517o offloodprone on expected flood protection. A levee breach or floodwall failure, like a dam communities) have levees that protectfrom I% break, can release a large wave of flood waters with high velocity. After a annual probabiliy floods; the length of these struc- breach, the downstream portion of the levee system may also act like a dam, tures is about 9,000 miles and they protect about catching and prolonging flooding of the once-protected area. 5,000 square miles of land. The Corps has designed and constructed about 10,500 miles of levees and floodwalls, most of which have been assigned to nonfecleral sponsors for operation and maintenance after construction. The Federal Emergency Man- agement Agency has established minimum design, operation, and maintenance i ro standards for levees that, for insurance purposes, must be met in order to be credited with providing protection against a 1% annual probability flood. The Tennessee Valley Authority owns and inspects 37 saddle dams and levees and treats them with the same criteria as regular dams, including inspections, instrumentation, and maintenance. Thirteen states have special regulations governing the construction of levees. 77" Channel Alterations Channel alterations increase the flow-carrying capacity of a stream's channel and thereby reduce the height of a flood. The various types of altera- tions include straightening, deepening, or widening the channel, removing debris, paving the channel, raising or enlarging bridges and culverts, and removing dams and other obstructions. Channel alteration is widely practiced by state and local governments to control flooding by rapidly conveying storm runoff through populated locales to downstream areas. The Corps and the Soil Conservation Service also undertake channel alterations. The Corps projects typically lie on larger Structural techniques to modify channels and control stream streams and rivers, while Soil Conservation Service works mostly in smaller flow include the construction of diversionary walls and streams on the upper portions of watersheds. The Soil Conservation Service gabions-prefabricated baskets of rock within wire cages has provided assistance in the construction of 10,700 miles of open channels. used to stabilize banks, City Creek Canyon, Salt Lake City, Utah. The use of channel modifications has decreased primarily because of the potentially adverse environmental impacts. Alternative designs are now devel- oped that include less straightening of channels, employ more gradual slopes, and use natural vegetation or riprap rather than concrete-lined channels. This minimizes destruction of fish and wildlife habitat, helps maintain water quality, and avoids undesirable downstream impacts. High Flow Diversions AN ALTERNATIVE APPROACH Diversions intercept flood waters upstream of a damage-prone or con- TO STORMWATER MANAGEMENT stricted area and convey them around it through an artificial channel or a The cost to communities of danwges caused by designated flow-way. Diversions may either completely reroute a stream or stormwaterflooding and investment in costly chan- collect and transport only excessive or potentially damaging flows. A negative nelization and other conduits can sometimes be aspect of such diversions is the false sense of security that may prevail in the reduced through different approaches to stormwater protected areas along with a lack of awareness that the floodway actually exists. management. In Arizona, for example, the larger, Several high flow diversions have been constructed along the Mississippi rapidly urbanizing communities all have someforin River. Excess water has also been temporarily diverted from the Great Salt ofstormwater management requirementsfor new Lake to an evaporation basin to prevent lakeshore flooding. development. All ofthe larger communities in the state's two urban count2@s, which include 7717o of Stormwater Management the shate's population, regulate the development of Stormwater management is the removal of water that falls directly onto watersheds. properties as opposed to flood water that flows onto the property from upstream sources or an ocean surge. Stormwater networks have historically been con- structed in urban and agricultural areas to remove these waters. Generally, the stormwater system removes the excess rainfall over a period of days and the temporary ponding floods only low-lying buildings and roads. A signifi- cant problem occurs when an agricultural zone with an adequate stormwater system is urbanized. Large areas are paved with roofs, roads, and parking, con- tributing to additional runoff. Often, shopping centers and other develop- ON-SITE DETENTION: ments are placed on natural drainageways. The pre-existing stormwater net- A MULTIPURPOSE TOOL work becomes inadequate for its new urban use. Localized flooding then occurs. Principal on-site detention measures include restrict- In an alternative approach often used in new developments today, runoff ing land clearing, creating impervious areas, and may be retained on the site, within a regional system, and total runoffwithin providingfor temporary storage of some or all of the a watershed may be managed so that discharges from different units reach the runofffrom a property. Many urban communities main channel at different times to reduce peak flows downstream. Natural have begun to recognize that areas devoted to storm- drainage systems may be used instead of concrete-lined channels or enclosed water management represent a significant portion of pipes. Many local ordinances now require a zero-increment runoff for new their open space land and opportunities for urban recreation and wildlife protection. Shallow grass- development, making such on-site detention a necessity. covered basins can be used as athLeticfields, parking lots, orfor other purposes during dry periods and as Shoreline Protection detention basins after storms. Equipping roofs or parking lotsfor temporari@ storing at Least a Part of Quasi-natural methods such as beach nourishment or artificial sand- the water thalfalls on them, designing streets in dune building are often used to attempt to restore an eroding beach as well hilly areas to prevent rapid runoff incorporating as protect development. Long reaches of shore can be protected by artificial nour- small retention basins into landscaping, using rock- ishment at a relatively low cost per linear foot. In addition, nourishment can filled pits to catch gutter runoff, and using pave- widen a beach and increase its recreational value. A well-known beach ments that let water seep through into the ground nourishment project is the 10. 5 miles of beach restoration in Dade County, below all slow runoff. Florida, which includes Miami Beach. However, these methods provide only temporary solutions to chronic long-term erosion caused by the diminishing supply of sediment in the littoral system. They also require periodic renourish- 38 ing during their 15- to 50-year life span. Even so, they are more cost-effective than large structures, such as groin fields or segmented offshore breakwaters. These structures can also build or increase beach width as well as provide protection, but erosion can occur downdrift if they are not properly designed. Structures like seawalls, bulkheads, and revetments protect development, but are not intended to renourish or widen the beach. Erosion can occur in front of them because the natural movement of the shoreline has been affected. Such structures as breakwaters and jetties, which are designed to protect harbors and navigation channels from wave action or to stabilize inlets, can also cause erosion on the downdrift side if they do not include a sand- bypassing system. Because of their high cost, few shoreline protection projects have been built without federal assistance, although most coastal states and many com- munities have participated in various ways. Some states, notably North Caro- lina, have adopted policies against new structural shoreline protection projects, opting to allow the shoreline to retreat naturally. Others, such as Connecticut, discourage construction of new structural projects, but do not specifically pro- ADJUSTING TO A hibit them. Still others, such as New Jersey, have active structural protection RETREATING SHORELINE programs. Some states have empowered localities to establish beach protection districts with the authority to collect taxes to fund long-term maintenance Where relative sea level rise is accelerating, coastal programs. Private landowners also use various techniques to forestall erosion flooding and erosion will also accelerate, placing bil- and reduce damages. These measures are necessarily low-cost and small-scale: lions of dollars worth of additional coastal property vegetation plantings, beach fill, breakwaters, groins, revetments, bulkheads, at risk. The nation will thus have the options of and seawalls. retreatingftom the shoreline, armoring it with pro- tective measures, or providing beach nourishment. The National Park Service's polky is to allow natu- Land Treatment Measures ralforces to act on the shoreline rather than trying to Land treatment measures reduce overland runoff from agricultural prevent erosion with structural devices. The state Of lands to streams or other waters by improving infiltration of rainfall into the North Carolina has taken a similar stance. Sow soil, slowing and minimizing runoff, and reducing the sedimentation that can federal agenct@s have limited the use of structural clo stream channels or storage reservoirs. These techniques are most com- measures onfederal lands, but when it is economi- 9 cally justifiable and environmentally acceptable, they monly used in agricultural areas. They include maintaining trees, shrubbery, will still construct pro)ects to protect existing coastal and vegetative cover; terracing; slope stabilization; using grass waterways; con- development. Likewise, many states limit structures tour plowing; conservation tillage; and strip farming. Some measures involve in undeveloped or light@ developed coastal areas, but building structures to retain or redirect runoff. Several land treatment meas- continue to permit structural projects to protect exist- ures involve little additional cos. -.0 the farmer, and some, such as no till or ing development. The Coastal Barrier Resources Act minimum tillage, actually red-.ce costs. Technical and financial assistance for excluded the use offederalfunds in "undeveloped" the more expensive techniques is often provided through public sources, par- coastal regions. ticularly programs of the U.S. Department of Agriculture. Although the impact of an individual measure is limited, extensive land treatment pro- grams can effectively reduce flooding in small headwater areas. r V Restoration of beach vegetation is one ineans of slowing beach erosion and transport, Beach grass planting by volunteers to preserve sand dunes, Newbugport, Massachusetts, 79 Modifying-t-he Impacts of Flooding Despite efforts to control flooding and to reduce susceptibility to it, floods do occur, with adVense-consequences on individuals and communities. A third strategy for mitigating floodplain losses is to help individualsand communi- ties prepare for and recover from floods. This can be done through informa- tion dissemination -and -education, spreading the costs of the loss over time, and transferring some of the individual losses to the community. It is not clear whether the present combination of flood insurance, dis- aster assistance, tax adjustments, and postflood recovery practices designed to implement this strategy is producing an equitable sharing of the capital and operating costs of floodplain occupancy among its beneficiaries, or shifting the costs from the individual -to -the public and government -agencies. Neither has there been a clear statement of how much, if any, of the cost of floodplain development should properly be borne by the general public. Some argue that all costs should be borne by those occupying the floodplain; others that devel- opment of the floodplain-provides economic benefits and, therefore, the general public should shoulder them. Information and Education Information and education activities for floodplain management have expanded dramatically since the 1960s, as illustrated by the number of publi- cations, technical manuals, brochures, conferences, workshops, organizations, SIR W, and media presentations now in existence. The effectiveness of this activity is U. difficult to assess. It is clear that many local officials and property owners still IL 0 do not thoroughly understand concepts of probability, cumulative impacts, off-site impacts, and functional values-all of which are important for success- S ful floodplain management. It is also clear that little of the material that has 'S Gul S been generated and released adequately integrates the flood loss reduction t i bappe jo @o and natural resources protection aspects of floodplain management. Much information on floodplain management andflood Much of the basic information about floodplain management was devel- hazard mitigation has been published in illustrated, clearly oped or sponsored by federal agencies, and includes technical design and appli- written manuals directed toward both private proper@y cation manuals, research reports, computerized databases, and public awareness owners and public offia@ls. materials. Federal and state agencies train their own personnel in floodplain management programs and activities. Both levels of government have actively provided financial and technical support to hundreds of conferences, seminars, STATE INITIATIVES TO and workshops on every aspect of floodplain management for professionals at EDUCATE THE PUBLIC all levels of government and the private sector, and for floodplain residents. In addition, states respond to individual inquiries from local officials, Texas holds workshops on the National Flood insurance agents, lenders, property owners, and the general public, and pub- Insurance Program tailored to the host county'sflood lish information tailored to the particular legal, administrative, and geo- situation, and invites lenders, insurance agents, real graphic situations of each state. Numerous nonprofit and professional organi- estate agents, and others. zations with concern for floodplain management have been formed in the last 0 In Tennessee, a community planner will visit a two decades. These organizations conduct research, produce publications, floodprone site upon request, recommend actions, and hold conferences and workshops, and provide a network through which direct the owner to more information or assistance. professionals can exchange information. 0 Wisconsin state law requires real estate agents to advise prospective Purchasers if a properly is shown Flood Insurance as floodbrone on ATIP maps. The Maryland Department of Natural Resources Insurance is a mechanism for spreading the cost of losses both over time and over a relatively-large number of similarly exposed risks. Until 1969, created "Farley Floodhound," a cartoon character who appears in a coloring book and helps 'flood insurance against flood losses was generally unavailable. Under the National pups" learn flood safety tips. --Flood Insurance Program, initiated in 1968 and significantly expanded in a Arizona is preparing a short course to be presented 1973, the federal government made flood insurance available for existing at local real estate schools. property in flood hazard areas in return for enactment and enforcement of floodplain management regulations designed to reduce future flood losses. The Oklahoma legislature passed a law in 1986 Although participation in the program is voluntary, of 21,926 communi- that reads, ",@f the premises to be rented have been ties in the nation identified as floodprone, 18,023 (82%) had joined the pro- flooded within the pastfiveyears and such fact is gram as of November 30, 1990. At the end of calendar year 1990, there were known to the landlord, the landlord shall include 2.39 million policies in force with $201 billion of coverage. From 1978 through such information prominently and in writing as part of an 1989, over 384,000 claims were paid totalling over $3.1 billion. Net receipts y written rental agreements." from policy premiums versus Iclaims payments varies substantially from year to year. From 1978 to 1989 the net operating deficit or surplus rangedfrorn a,- 40 deficit of $261 per policy in 1979 to a surplus of $98 per policy in 1987. A sur- plus was realized in fiscal years 1986, 1987, and 1988. As of October 1, 1988, NFIP Flood Claims Paid -the flood insurance fund was operating with a ne@t surplus of $450 million, the 1978-1987 result of a combination of rate increases and relatively low flood losses during those years. The accumulated surplus provides a reserve for years with cata- Amount of strophic losses. State' Claims Paid In 1983, the Federal Insurance Administration initiated its "Write-Your- 'Own" program whereby private insurance companies, under special arrange- Alabama 87,805,791 ments, are permitted to-sell and service flood insurance under their own names. Alaska 332,839 The success of this program is evidenced by the fact that -80 % -of all flood Arizona 14,064,010 insurance is presently sold by the participating WYO insuranc Ie companies. Arkansas 10,800,307 Insurance premiums are based on the location of a-struatire within the California 108,846,266 flocidplain and are determined rimarily by the hei t of the structure's lowest Colorado 3,223,467 p - 94 - @ . - - Connecticut 34,906,126 floor in relation to the -height of water during a base flood. Higher rates apply Delaware 1,929,167 to structures subject to fast-moving waters. New and substantially improved District of Columbia 101,518 structures in the floodplain that are not properly elevated to the base flood Florida 165,125,349 level are subject to higher rates than structures already in the floodplain at the Georgia 8,455,396 time a community joined the program. Since 1974,-flood insurance rates have Guam 17,492 Hawaii 10,354,101 increased several times in order to reduce the amountof the federal subsidy Idaho 499,193 and bring the cost of flood insurance closer to true actuarial rates. In early Illinois 81,307,867 1988 the administrator of the Federal Insurance Administration announced Indiana 13,289,339 success in "making the. National Flood Insurance Program self-supporting Iowa 3,101,421 for the historical average loss year." Even so, the existing premium base is not Kansas 12,957,557 large enough to pcrinit the National Flood Insurance -Program to operate on Kentucky 48,913,951 a fully actuarial basis.- But because only 15% to 30% of the nation's floodprone Louisiana 502,019,965 structures are insured, there is plenty of room for increased market penetra- Maine 15,921,597 Maryland 21,859,402 tion. Several strategies for increasing the number of insured structures have Massachusetts 40,890,955 been suggested, including requiring more stringent enforcement by lenders Michigan 23,999,710 of the mandatory- purchase requirements, increasing public awareness of the Minnesota 16,518,655 flood hazard, imposing disclosure requirements on-real-estate agents, offering Mississippi 108,496,982 special insurance coverage and policy riders, and maintaining premiums at Missouri 113,043,717 more affordable levels. Montana 11943,610 Nebraska 9,460,795 Concern has been expressed that flood insurance-prem -ium costs have Nevada 1,891,589 increased to a level so high that many people do not purchase flood insurance New Hampshire 3,729,914 -unless they are required to do so by a mortgage lender or unless they have New Jersey 117,979,379 experienced flooding.- Many of those who do purchase insurance allow it to New Mexico 490,587 lapse later. The net. result appears to be that only- those individuals with the New York 105,271,504 greatest risk actually purchase and maintain flood insurance. To maintain North Carolina 15,495,792 actuarial rates for-this group, insurance rates may beforced even higher. North Dakota 9,786,873 Many of the claims paid out each year are on strixtures that have previ- Ohio 29,549,982 Oklahoma 60,986,298 ously incurred damage.. The Federal Emergency Management Agency defines Oregon 2,404,346 these as-repetitive loss-structures-those for which two or more losses of more Pennsylvania 61,971,275 than $1,000 (build -ing and contents combined) have been paid during the most Puerto Rico 32,200,608 recent 10-year period. From January 1980 through December 1989, 2 7.5 % of Rhode Island 7,828,172 the total losses and 32.5 % of the amount paid on them were repetitive losses. South Carolina 10,324,333 Most repetitive losses are suffered by structures built before regulations and South Dakota 1,403,419 Tennessee 8,482,208 are for relatively -small amounts; the building damage is usually a low pe -r- Texas 575,588,046 centage-of the building value (53.2% of repetitive losses are- for 10,70 or less Utah 4,439,661 of the building value). A high proportion of the repetitive loss claims pay- Vermont 1,140,338 ments are for contents. Virgin Islands 2,332,664 Repetitive losses tend to be concentrated in a s mall number of National- Virginia 59,077,329 Flood Insurance Prograrn communities, and many occur outside the.desig- Washington 13,196,518 nated floodplain. Six repetitive loss communities have had 29.7 % of all the West Virginia 67,738,531 repetitive losses; 20 communities have had 44.3176 of the losses. Although 12 Wisconsin 3,295,144 of the top 20 repetitive loss communities are coastal, only two have significant Wyoming 1,038,852 Totals 2,657,819,907 numbers of policies in coastal areas. Only 2 2 of the top 100 repetitive loss. - communities are primarily subject to tidal flooding.. Because of this it is Source. Flood Insurance Producers National Committee believed that the repetitive loss problem is more related to riverine or storm- 1 "State," as defined by FENIA program regulations, water floodin than to tidal flooding. means any state, the District of Columbia, the territories - 9 and possessions of the United States, the Commonwealth The Federal Insurance Administration has implemented-a Community of Puerto Rico and the Trust Territory of the Pacific Rating System to encourage communities to go beyond the required standards. Islands. the incentive will be a reduction in flood insurance premiums for policy- holders within communities that take approved actions to reduce flood losses. 41 Amount Paid for NFIP Losses, Top 20 Repetitive Loss Communities 1980-1989 by Number of Losses Total Paid'= $2.27 Billion January 1980-December 1989 Repetitive Losses (33%) York, e .1,256 12. S@ i x@lom@'Conty, @/ Towns 1 of Wayne, liforhia - 604 17. eoi Co'nty, ey - 742 Ilin i 51 6. SSin Chad Co n Missouri - 2, 't Saint Louis C Miss 3 City of Hou t n, ex 6 Cit of K4obile,_V IlHa y 41 Ha ty, Texas - 2,37 A a arna, - tm b Ga eston County, Texas - 544 Nonrepetitive Losses (67%) 16. City f Texas City, Texas 5 t24 20. Mont unty, Tex ity f Saint Petersburg, Source: FEMA/FIA lori -533 1. Jefferson Parish, Loui * -7,871 2. Orleans Parish, Louisia -5,153 8. St. Bernard Parish, Louii a - 987 10. City of Gretna, Louisiana - 674 11. City of Kenner, Louisiana - 605 Source: FEMA/FIA 19. East Baton Rouge Parish, Louisiana - 483 5. Puerto Rico - 2,348 ACCEPTING THE NFIP Today, flood insurance is largely unavailable except under the National During the first 15 years of the National Flood Flood Insurance Program. An exception is a Lloyds of London-based policy Insurance Program, communities often challenged it which has as many policyholders in Utah as does the National Flood Insur- and resisted adopting the required regulations. Now, ance Program. Some private policies or riders are available for basement because communities have seen the regulations sup- flooding; these were initiated after the National Flood Insurance Program ported in the courts, because there has been intensive limited its coverage for basements and subsurface flows. Flood insurance is media coverage offlood disasters, and because con- included as part of a comprehensive flood insurance policy for some large cerns about local habihy for flood damages have businesses with offices and land holdings in many locations, in and out of the been heightened, there is increased awareness of the floodplain. Crop insurance available under the U.S. Department of Agricul- program's benefits. As a result, NFIP regulations ture's Federal Crop Insurance Corporation provides protection to agricultural and otherfloodblain management activities have producers from losses caused by insects, disease, fire, hail, drought, floods, become institutionalized, and generally accepted as freeze, and wind. a community responsibility. Tax Adjustments Most provisions of federal, state, and local tax codes are designed to encourage development without regard to whether it might take place in a TAX POLICIES TO MODIFY THE floodprone area, while relatively few provisions provide incentives to leave IMPACTS OF FLOODING land in its natural state. Some tax-based incentives for development are In 1987 Des Plaines, Illinois, began a permit reductions in property taxes, abatement or deferral of taxes to entice or retain surcharge of $200forfloodplain development projects businesses in an area, and the establishment of enterprise zones or other spe- to helpfinance city flood protection activiti@s. cial business zones to promote development and employment in economically 0 The city of Stamford, Connecticut, has required depressed areas. These make locating businesses, homes, and other develop- developers of certain projects constructed in theflood- ment in some floodprone areas financially feasible and even attractive. On top plain to contribute funds for the operation and main- of this, the federal Internal Revenue Code and many state codes also provide tenance oftheir automatedflood warning system. casualty loss deductions on income taxes to those suffering flood losses. After 0 After disastrous flooding in 1982, the state of disastrous floods, many states and localities provide additional types of tax Connecticut enacted special Ao d relief legislation relief, reducing or temporarily suspending real estate taxes or business taxes that included a provision for tax abatements for those for those affected by flooding, for example. whose property was damaged more than 10 5o' of its Still, more integration of tax policies and floodplain management is value. Towns were authorized to abate up to one- occurring. The Tax Reform Act of 1986, for example, made major changes third of the taxes due, and the state would reimburse in the Internal Revenue Code, some of which have an impact on floodplain thernfir 90 % of the taxes lost. Eighteen towns management. Individual casualty loss deductions under $100 are now pro- offered some tax abatement to property owners, and the state reimbursed the towns a total of $49,504. hibited, and the deduction is limited to the portion of the loss that exceeds 10 7o of the adjusted gross income. The new rule does not apply to business property. The Act also eliminated or restricted many of the tax deductions and credits that had been used as incentives to build in floodplains, on barrier islands, and at other hazardous locations. 42 Flood Emergency Measures Flood emergency measures are typically carried out by local civil defense, Al police and fire departments, public works agencies, and public health person- nel, supplemented as necessary by assistance from state and federal agencies. Emergency activities during and immediately after a flood may include removing people and property from areas about to be flooded; sandbagging around individual structures and constructing emergency dikes to direct water away from vulnerable areas; search and rescue; and steps to protect the health and safety of residents. To be successful, flood emergency measures must have the thorough involvement of the private sector, from individuals who evacuate and take Emergemy response toflooding is usually the responsibiliy of local agencies, with supplemenW assistancefrorn state household-level emergency precautions, to the organized group efforts like andfederal agencies. However, private citizens are @ypicat- those of the American Red Cross local chapters. Private contractors work for ly the first to respond and provide assistance to others. communities and individuals to remove debris and repair homes, roads, bridges, and other property damaged from floods. Some states have standing contracts with private businesses to provide emergency services in disasters. The 1983 floods in Utah showed what literally thousands of volunteers, acting individually and in groups, can accomplish during flood emergencies. The Corps is the federal agency most commonly involved in flood emer- gencies, under authority of P.L. 84-99, which authorizes it to help in flood fighting, repair and restoration of flood control works, provision of emergency water supplies, implementation of advance protective measures, and the per- formance of other hazard mitigation activities. The support may take the form FIGHTING FLOODS IN UTAH of technical assistance, materials, equipment, or services. The Soil Conserva- In ear@ May 1983 Salt Lake County, Utah, began tion Service may also become involved with emergency efforts. The Federal 24-hour monitoring of critical streams in anticipation Energy Regulatory Commission requires emergency action plans for all its Of severeflooding as a result of a large snowpack and licensed dams. The Federal Emergency Management Agency helps state and unusually cold spring. The most vulnerable flooding local governments assess the extent and severity of damage in order to seek location was identzfied as 13th South, where three disaster assistance. State emergency services agencies generally coordinate state streams came together. Ciyforces, with assistance resources and activities during flood emergencies, and the state police and from volunteers, built temporary dikes along the street transportation or public works departments, the state national guard, and the so it could be used as a channeL After a sudden agencies responsible for dam safety and water resources also play major roles. thaw on May 26, the county and city declared an emergency andflood control plans were activated. Disaster Assistance Two days later another creek reached a flood dis- charge nearly double its previous record and went out Disaster assistance is provided by federal, state, and local governments, Of control. Volunteers were called in to sandbag 1.5 and the private sector. It may take the form of financial relief, or of help to miles of State Street through the ciy,- flood waters repair, replace, or restore facilities damaged or destroyed by a disaster. The were successfidly controlled in this temporary river. system is most often efficient and adequate to provide the necessary financial During the extended period offlooding and subse- relief to individuals and communities. quent cleanup in Utah in 1983, volunteers put in an The greatest source of federal disaster assistance is provided under the estimated 50, 00 0 days of work in Sah Lake City, Disaster Relief Act of 1974 and takes the form of grants to the states from the and about 100, 000 days in the rest of the couny. The value of the volunteer work has been estimated President's Disaster Relief Fund after Presidentially declared disasters. The at over $18 million. assistance is administered by the Federal Emergency Management Agency, which also directs and coordinates the disaster assistance functions of all federal agencies. The Small Business Administration issues its own disaster declarations and makes low-interest loans available directly to eligible indi- =311I.-E.-M". N" .",axg, viduals and businesses to replace or repair damaged real estate, inventory, ion or other business property. The Federal Highway Administration provides funding assistance for damaged highway facilities that were constructed with federal aid. Under the Emergency Watershed Protection Program, the Soil Conservation Service may directly undertake emergency work such as clear- ing debris from channels and stabilizing streambanks. As mentioned above, the Corps has authority to provide assistance for disaster the Corps has authority to provide assistance for disaster preparedness, advance protective measures, rehabilitation of flood control works damaged or destroyed by State Street, Salt Lake City, Utah, May 1983. (Street flood, protection or repair of federally authorized shoreline protection works was used as a temporary water conveyance path.) threatened or damaged by coastal storms, and provision of emergency drink- ing water. The Farmers Home Administration State Director may make emergency loans to farmers, ranchers, and oyster planters. Under the Emer- gency-Conservation Program, an Agricultural Stabilization and Conservation Service State Director may designate areas eligible for cost-sharing grants of up to 64% to rehabilitate farm lands damaged by natural disasters. 73 Although all state and most local governments have programs to coor- dinate and provide assistance during an emergency, few have special funds for financial assistance to victims. Most states limit their own disaster assistance funding to local governments, rather than extending it to businesses or indi- viduals. All states now contribute some of the nonfederal share of assistance for Presidentially declared disasters. States may also declare their own emer- gencies or disasters; 28 states then provide assistance to localities out of a governor's emergency fund. Local governments may provide disaster assistance to their residents and business community, most commonly through some form of tax break. Many Most federal disaster assistance is provided through localities have joined mutual aid agreements with nearby communities to pro- FEMA, although the Small Business Administration, Federal Highway Administration, Soil Conservation Serv- ice, Army Corps of Engineers, Farmers Home Adminis- ration, and Agricultural Stabilization and Conservation Dollars Paid for Disaster Assistance, 1965-89 Service also administer programs. State and local govern- All Disasters versus Floods and Hurricanes mens, as well as private, nonprofit organizations such as the Red Cross, are also centrally involved in providing aid 1700 following flooding. 1600 Type of Disaster Disaster Assistance Center, DeRidder, Louisiana, 1983. 1500 1400 All Disasters (Total = $6,735,868,000) 1300 Floods & Hurricanes (Total $5,185,337,000) 1200 1100 1000 900 800 700 600 500 400 300 THE "AVERAGE" DISASTER 200 100 A 1990 preliminary report by the U. S General Accounting Office noted that in an "average" dis- aster about 2,000 individuals and families seek fed- eral disaster assistance and the Federal Emergency Source: FEMA Year Management Agency spends about $10 million. Number of Presidentially Declared Disasters, 1965-89 All Disasters versus Floods and Hurricanes 55- Type of Disaster 50- All Disasters (Total = 657) 45- Floods & Hurricanes (Total 508) 40- 35- 30- 25- 20- 15- A 44 Source: FEMA Year vide equipment, personnel, and other disaster assistance. Research has shown that local governments have the capacity to assume a much higher proportion NAGS HEAD PLANS ITS RECOVERY of losses than they usually do within the existing framework of federal and FROM A FUTURE FLOOD state programs. The Town of Nags Head, formerly a quaint village of A number of national voluntary organizations provide disaster relief seaside cottages on the Outer Banks of North Caro- services, primarily emergency shelter, food, clothing, and medical aid. Some lina, is now a resort communityfacing substantial also provide longer-term assistance, such as rebuilding homes or job place- growth and development. One of its main concerns is ment. A committee known as the National Voluntary Organizations Active in protecting the quality of its natural resources and Disaster coordinates 11 private relief groups. Three of these organizations, the preparing its res&ents and thousands of visitorsfor American National Red Cross, the Salvation Army, and the Mennonite Dis- hurricanes and coastal storms. With guidancefrom aster Service, were formally recognized in the Disaster Relief Act of 1974 and the states Coastal Area Management Act Program, have signed memoranda of agreement with the Federal Emergency Manage- Nags Head began preparing a local land use plan ment Agency formalizing the provision of their disaster assistance. In addition that would incorporate a Prisorm mitigation pro- to national organizations, local churches and other voluntary groups often gram, warning and preparedness plans, and post- provide significant assistance during and after disasters. storm reconstruction polky. In developing its plan, Nags Head surveyed all its Postflood Recovery properties at ri@k, finding that 84 01o of the town's 2,500 buildings lay in the 100-yearfloodplain and Postflood recovery work, aided by many types of disaster assistance, 44 % in the high hazard areas. There were also four has been largely effective at restoring flood-damaged communities and indi- pub& buikiings, 27 miks of streets, and 32 miles of vidual properties to their preflood condition. Unfortunately, this has not public waky mains within thefloodblain. always been the wisest course of action, because returning to the status quo After a series of meetings and workshops, the Board leaves the door open for a repeat of the disaster. Numerous recommendations of Commissioners adopted policies and actions "to have been made over the years to alter recovery procedures to take advantage reduce, to the extent possible, future damageftom of the opportunities presented immediately after a flood, when outside exper- hurricanes and severe coastal storms." There are 12 tise and money flows into a community, damaged or destroyed facilities are miliganim policies, including using the capital waiting to be repaired or replaced, and local attitudes toward mitigation are imoovernents program to encourage growth away more flexible than before. It was thought that this would be the best time to from high hazard land into pub& open space, and opposing construction offinger canals and other identify mitigation actions that might easily be taken and to delay reconstruc- prol.ects that destroy the protection proviiied by natural tion until wise decisions about the vulnerability of future development could features. be made. Gradually federal agency policies began to change so that over the past two decades individuals and communities have had to meet certain con- The poststorm reconstruction policies are designed to ditions in order to receive disaster assistance. These include protecting the take advantage of the natural land clearance provided environment, implementing floodplain management measures, purchasing by severe storms. When it begins to redevelop the cleared arms, the town will limit reconstruction of flood insurance, and taking action to mitigate hazards. Passage of the Disaster substanti@ damaged buildings and public utilitiis, Relief and Emergency Assistance Act in 1988, which allows federal disaster will rebuild public structures strong enough to be used assistance funds to be spent on mitigation activities and not just to rebuild to as shelters, and will not permit ocean(ront reconstruc- the predisaster condition, signalled a new approach to postflood recovery. tion until the state reestablishes the setback line. (Adaptedfrom ASFPM News & Views, 1988) Restoring and Preserving the Natural and Cultural Resources of Floodplains The strategies of preserving and restoring the water resources, living resources, and cultural resources of floodplains are generally intertwined. The best way to protect these floodplain resources is to avoid development within flood- plains. It has been suggested that stronger federal support of programs to set aside floodplains from development is needed, and that federal policies and procedures actually do not encourage and sometimes even obstruct innovative approaches to preserving natural floodplains. Several federal policies, for example, limit the features of water resources projects to those that have quantifiable economic benefits. Because many natural and cultural resources are difficult to quantify, or add only incremental benefits, the cumulative effect of eliminating these features may not be taken into account. Limited preservation and restoration can be accomplished indirectly through flood loss reduction activities. Numerous programs at all levels of government establish policies that encourage, but generally do not require, protecting floodplain resources. Natural resources management itself is usu- It has been difficult to quantify the value of the natural ally not focused on floodplains but instead addresses a particular resource and cultural resources of J76odolains and therefore difficult throughout its natural range. to justify government expenditures to preserve floooplains in their natural state. However, there is a growing desire among the public to make sure that the natural bene/ns of the riparian environment are safeguarded. 75 Regulations Regulatory measures are among the most widely used and most effective means of helping to protect the natural and cultural resources of floodplains; they are employed at all levels of government. There are several drawbacks to using them, however. Restrictions on the use of private land in order to pro- tect natural resources are generally viewed less favorably by the public and the courts than are restrictions to protect human lives or property. Because of this, regulations must be well designed to avoid being ruled unconstitutional takings. Finally, protective regulations sometimes conflict with flood loss reduction measures, especially with structural works. Many federal environmental regulatory programs directly or indirectly protect floodplain natural resources. These include programs established to implement the Clean Water Act; the Safe Drinking Water Act; the Federal Insecticide, Fungicide, and Rodenticide Act; the Solid Waste Disposal Act; the Endangered Species Act; the Natural Historic Preservation Act; and others. Statewide floodplain, wetland protection, or similar regulations may be THE WILD AND SCENIC RIVERS ACT applied directly by a state or, as is more often the case, by local communities The Wild and Scenic Rivers Act of 1968 establishes according to state-established standards. Any alteration of the natural topog- as national policy the protection of certain selected raphy or habitat, or any damage to flora or fauna requires a permit in some rivers (or segments of them) with particular natural states. Cumulative impacts are considered during the permit review process and cultural value. The National Park Service main- in a few states, and mitigation of the loss of natural resources is often a con- tains a list of rivers that are potential additions to dition for permit issuance. Several states specifically protect wetlands with the designated system. The Act prohibits the Federal programs that outline minimal criteria for permit issuance and prohibit all Energy Regulatory Commission from licensing any other development. dam or other work on or directly affecting any river Local regulations, such as zoning and subdivision regulations, building of the system and likewise prohibits otherfederal codes, housing codes, and sanitary and well codes, may directly or indirectly agenciesfrom activities that would have a direct and manage natural resources by including provisions for protecting habitat, water adverse effect on the values incorporated into the Act. Further, allfederal agencies are required, as part of quality, and open space. Relevant provisions include setbacks from the shore, their normal planning and environmental review limited density in coastal areas, restrictions or prohibitions on certain kinds processes, to avoid or mitigate adverse effects on of development in such sensitive areas as barrier beaches and sand dunes, and rivers being consideredfor wild and scenic specification of uses that will not degrade the natural resources of the site. designation. FEDERAL REGULATIONS AND THE NATURAL RESOURCES OF FLOODPLAINS The Section 404 program under the Clean Water Act helps protect the natural resources of floodplains by regulat- ing the discharge of dredged or fill material into waters of the United States, including adjacent wetlands. Permit appli- cations are subject to a public interest review that includes consideration of floodplain values and flood hazards, and compliance with the Environmental Protection Agency's section 404(b)(1) guidelines, which incorporate extensive environmental criteria to prevent the loss of aquatic resources and minimize adverse environmental impacts. One aspect of the guidelines provides for the mitigation of adverse impacts at one site by restoring alternative degraded sites; it has been responsible for a number of experiments in rehabilitating degraded wetlands and creating new ones. One of the most significant developments in protecting rare plant and animal species, many of which live in flood- plain habitats, was the Endangered Species Act of 1973, which authorizes the designation of habitats critical to the survival of threatened and endangered species. It directs federal agencies not to authorize, fund, or carry out actions that mayjeopardize their existence or modify their habitats. Many states have developed their own programs of iden- tifying and protecting rare and endangered species. 0 The National Historic Preservation Act of 1966 was passed, in part, because Congress recognized that federal projects, such as highways, dams, and urban renewal, had damaged or destroyed thousands of historic properties during the 1950s and 1960s. The National Historic Preservation Program has operated as a working partnership between fed- eral, state, and local governments, private citizens, the Advisory Council on Historic Preservation, and the National Trust for Historic Preservation. The federal government provides guidelines, technical assistance, and grants in aid for state and local historic preservation efforts, and monitors its own activities so that they do not unnecessarily harm historic properties. State historic preservation officers coordinate the program, assist local governments and the pub- lic and give them advice on preservation matters, and carry out other aspects of the national program on behalf of the federal government. Preservation work at historic sites is done by localo governments, nonprofit organizations and institutions, corporations, and individuals. 46 Development and Redevelopment Policies Important federal policies and programs affecting the design and location PROTECTION OF of services and utilities in the nation's floodplains have been established in the FLOODPLAINS AND WETLANDS executive orders on floodplains and wetlands and in accord with the Wild and THROUGH REGULATION Scenic Rivers Act and the Coastal Barrier Resources Act. The executive orders Many Michigan communities have adopted com- require federal agencies to evaluate their proposed actions in light of, among binedfloodplain and wild and scenicriver regula- other considerations, the proposed impact on the natural resources of flood- tions to preserve the natural resources of these areas. plains. Some states have executive orders to control placement of public facili- 0 Besidesfloodplain regulations that require permits ties on floodplains, while others directly regulate these uses through statutes. forfilling, grading, or construction, Virginia Beach, A number of federal laws and programs provide funding and other assistance Virginia, has adopted coastal wetland and sand dune for acquiring and protecting floodplain land. protection regulations that require building setbacks. States protect natural and cultural resources with open space and rec- 0 A zoning ordinance in Clearwater, Florida, reation programs that are occasionally linked to floodplain management. includes special regulationsfor environmental@ sen- Most states have at least one program through which wetlands are brought sitive areas, including mangrove andfreshwater into public ownership, although that usually was not its specific intent; fre- swamps, barrier islands, coastal beaches, natural quently wetlands are acquired because of their habitat, open space, or other drainageways, and aquifer recharge areas. value. Most states have now enacted legislation to protect wetlands; many of 0 In order to reduce bank erosion, increase ground- these states have found that the incremental loss of small wetland areas still water infiltration, and provide wildl2fe habitat, several results in an unacceptable cumulative loss. In response, they are acting to California communiti@s have adopted ordinances tighten existing wetland protection programs. A related measure is mitigation regulating the removal of riparian cover along banking programs, which provide for the creation or enhancement of wet- watercourses. lands at one site as compensation for damage that has or will occur to wet- 0 In Northampton, Massachusetts, 1,500 acres lands as a result of development at another site. At least 10 mitigation banks offloodolain along the Connecticut River have been were functioning in the United States as of 1986. Mitigation banking is only placed in an exclusive agricultural use district. appropriate in certain situations and requires a great deal of administrative * In East Hampton, New York, floodplain regula- and planning effort, financial support, and commitment. tions are supplemented by a beach grass protection Several thousand communities have acquired a portion of their flood- ordinance, tidal and inland wetland regulations, a plains for parks, parkways, wildlife areas, conservation, agriculture, or other dune setback regulation, and scenic easements to pro- environmental or social uses. Some local jurisdictions have moved toward pro- tect wetlands, dunes, and other areas. grams to combine other community objectives with floodplain management, including open space, hiking, cycling, water quality, aquifer protection, wetlands protection, and the provision of fish and wildlife habitat. These multiobjective programs typically take two forms: greenway or river corridor projects and community redevelopment projects. The State and Local River Conservation Assistance Program, administered by the National Park Service, is the prin- cipal federal program for providing information, technical assistance, and limited funding for such river planning. PROTECTION OF FLOODPLAINS AND WETLANDS THROUGH DEVELOPMENT POLICY 0 A Glastonbury, Connecticut, floodplain regula- tion includes a density transfer mechanism un er which development rights may be shiftedfrom one place to another. & In the largest federally funded watershed management project in history, the U.S. Army Corps of Engineers purchased 8,500 acres of wetlands in the Charles River watershed up- stream from Boston, Massachusetts. These wet- lands provide 50, 000 acre-feet of flood water storage, eliminating the needfor a flood control dam or other structure and constituting significant areas of habitat and open space. 7, @7_ New Jersey used funds from the U.S. Fish a nd Wildlife Service's Federal Aid to Wildlife 7-7 Fund to acquire additions to the 4,400-acre Cape Ad- a Wetlands, which the state maintains as a An adjacent 315-acre salt marsh wildlife refuge. was purchased, and the owner of the property do- Charles River naturalflood water storage area near Dedham, Massachusetts. noted 25% of the land to the state, providing the state's required matchingfunds. Continued on next page 77 PROTECTION OF FLOODPLAINS AND WETLANDS THROUGH DEVELOPMENT POLICY Continuedfrom previous page When the Wynoochee Dam was constructed in Washington State, a portion of wildlife habitat T-7 7 A& was lost under the lake and a number of elk and deer were left homeless. To mitigate the loss, the U.S. Army Corps of Engineers acquired 1, 034 acres of land to provide replacement winter L rangeland. Within each area, cultivated fields supply winterforage, while the remaining area _PF777@_" serves as buffer and as habitat. 7" Florida's Save our Rivers Program is one of several that have protected substantial acreage for habitat, water quality, watershed protection, and Floodplain managernent efforts have sometimes been unsuccessful because they are seen as benefitting only recreation. Land has been purchased to restore sekct groups at the expense of an entire communiiy. Therefore, some jurisdictions have developed programs channelized or impounded rivers thatfeed the that combine other communiy objectives-the development of open space and recreation facilities, or the protec- Everglades, to restore the Kissimmee River to its tion of wetlands and water qualio, for example-with floodplain managernent. original channels, to conduct a pilot project on Greenbelt park, Maryville, Tennessee. marsh habitat renewal, and to preserve Parts of the Green Swamp. The private sector, operating largely through private, nonprofit organi- * The Mecklenberg Couno, North Carolina, zations, is heavily involved in acquiring land to protect it for open space and Greenway Master Plan provides for the preserva- habitat, and much of that land is wetlands or floodplain land. As of 1989 the tion offloodblains along more than 20 creeksfor Nature Conservancy was responsible for the protection of 3,643,352 acres in passive recreation, habitat protection, and reduc- 50 states, Canada, Latin America, and the Caribbean. The Audubon Society tion offlood damages. A network of greenways is and Ducks Unlimited have active programs to help preserve wetlands. planned that will include 4,000 acres and 60 miles of trails. As of 1986, over 1,000 acres Information and Education had been acquired through donations, local park bonds, and dedications. Information, education, and technical assistance are becoming more important as natural resource managers and interest groups realize the benefits of a public that is well-informed about natural systems and about the conse- quences of decisions that affect them. Technical information and public edu- cation about the natural and cultural resources of floodplains is provided by the Environmental Protection Agency, the U.S. Fish and Wildlife Service, the Office of Coastal Resources Management, and other federal agencies through press releases, newsletters, magazines, and television programs. Most states have active programs within their natural resources, environmental protection, PROTECTION OF and parks and recreation departments that prepare and distribute literature, FLOODPLAINS AND WETLANDS films, and other materials. Many offer instructional courses to staff and offi- THROUGH TAX ADJUSTMENTS cials of local communities. Natural resource inventories and mapping are At least 43 states offer real estate tax incentives to major components of many state programs. Hundreds or thousands of private leave land in agriculture, forestry, and certain other organizations exist across the country to inform and educate the public about open space uses; undevelopedfloodplains qualify natural resources, including those on floodplains. Environmental values are under some of these statutes. widely taught in schools at all levels, and popular television programs reach 0 A Florida program earmarks for the Water a wide audience. Research is an important predecessor to education and Management Lands Trust Fund the revenues from technical assistance, and the information base on natural resources is being a documentary tax of $.075 per $100. 00 on all real broadened continually. estate transactions. The money is used to purchase Improved documentation and quantification (including dollar values) and manage floodplains and wetlands. Revenues of the value of natural floodplains are needed to improve public understand- over the next 30 years are expected to approach ing and acceptance of the need for protection. For example, few developers $1 billion. seem to realize that floodplains and wetlands have great aesthetic appeal, that *Minnesota's Tax Exemption and Credit Program in their natural state they can simultaneously enhance property values and has two main components. Under thefirst, eligible continue to fulfill their normal natural and cultural functions. wetlands are exemptfrom Propery taxes. Under the second, landowners .who agree not to drain wetlands Tax Adjustments in a givenyear rece2ve a tax credit. Excess creditsfor wetland propery may be applied to the landowner's Positive incentives for the preservation and restoration of floodplain tax liabilityfor contiguous property. The state reim- resources can be provided through several kinds of tax adjustments, although burses countiesJor revenues lost due to the exemptions this technique has not been widely used. Federal income and estate tax bene- andfor the value of the tax credits. fits, which are available to individuals and organizations who donate land and provide easements to governments and eligible nonprofit organizations, have 48 been a major factor in facilitating private donations of property with valuable wildlife and habitat functions or historical significance. Most conservation organizations are tax exempt, and many of them are active in protecting the natural and cultural resources of wetlands. Almost all states offer tax incen- tives for open space uses. Administrative Measures Many different administrative measures can be used specifically to pre- serve and restore the natural and cultural resources of floodplains, including restrictions or conditions on contracts, grants, loans, permits, and licenses; encumbrances during land conveyance; delegation of responsibility for flood- plain activities to a specific authority; comprehensive planning; systematic review of agency programs to identify opportunities for preservation and res- toration; and coordination among federal, state, local, and private agencies to implement unified efforts. Some of the most important administrative meas- ures address the inventory, classification, and mapping of wetlands, wildlife, aquifers, and other natural resources. It is necessary to know what natural resources exist in the floodplain and what their individual and collective value is before making land use decisions that will sustain those values and functions. Planning historically has been used by governments for many kinds of activities besides natural resources management. Comprehensive planning provides an opportunity for taking a holistic view of floodplain resources while also meeting other local needs, such as water supply, agricultural ero- sion control, recreation, and economic development. This sort of planning is getting increasing attention at the state and local level, and typically incor- porates several of the tools discussed above. Multiple Use Planning for a Floodplain PART III THE'EFFECTIVENESS OF FLOOPPLAIN MANAGEMENT 1" or "'vow X. Perception and Awareness of Floodplain Losses Both individual and institutional perception and awareness of flood risk and vulnerability affect floodplain management. Although substantial progress has been made in increasing institutional awareness and response, individual per- ception and awareness generally falls far short of what is needed. This short- fall makes itself unpleasantly felt in the unwise development of flood hazard areas and in disregard for the value of natural floodplains, Recognition of Risk Local perception of flood hazards-by both governments and floodplain residents-is related to previous experience with flooding; the extent to which the floodplain is developed; the existence of structural control measures; the seriousness of the flooding in relation to other community problems; and atti- tudes about land use, water resources management, and regulations. In general, the threat of damage from coastal flooding seems to be taken more seriously FLOODPLAIN MANAGEMENT TERMINOLOGY Some misperceptions aboutfloodplain management are the result of simple lack of understanding. For example, probably the most misunderstood concept is the "100-yearflood.- The term is often talxn liter- ally, causing individuals to believe, incorrecto, that if they or their community have experienced a 100- -INN" yearflood, a similar one cannot occurfor another century. The terms '7% annual chance flood" and "national baseflood standard" have been suggested jq@ as less-misleading substitutes. Use of the term 'floodproofing" also can give a e4s false sense of securiy about susceptibility to flood damage. The techniques involved in floodproofing d9 7 not make a structure comptete!@ safe from flooding. The term 'flood-resistant construction" has been suggested as an alternative. Although public knowledge concerningflood risks has increased significantly in the last 30years, development in hazar6gusareas is still occurring. Flooding and alluvial fan, Magnolia Spring Canyon, Rancho Mirage, California, July 1979. by communities than is damage from riverine flooding. Because most people REGULATION AND discount the probability of loss from infrequently occurring events, such as PUBLIC AWARENESS large floods, individual and community experience with flooding results in Many regulatory measures have been instituted by both heightened perception of risk and increased attention to solving flood governments in an effort toforce individual aware- problems. The perceived seriousness of the flood problem is directly asso- ness offlood hazards and protective action. For ciated with the extent of floodplain development and existence of intensive example, the National Flood Insurance Program is land uses in the hazardous area; increasing development may result in greater voluntary, but changes have been made in the law awareness of flood problems. The presence of structural flood control measures since it was passed in 1968 in order to encourage has varying effects on perception of risk and subsequent responses; structural greater participation. Primary among these was the measures may contribute to a sense of complacency, as though the problem Flood Disaster Protection Act of 1973, which pro- were "solved." hibits nonparticipating floodprone communitiesfrom receiving disaster assistance after aflood. Another Private citizen perception of risk may be quite different from that of local mechanism intended to promote awareness and com- officials. Even if the risk is acknowledged, the advantages of a floodplain loca- phance is the provision thatfederally insured banks tion to the individual property owner may seem to outweigh the disadvantages. and otherfinancial institutions require purchasers of Homeowners also may be more concerned with the effect of floodplain regula- homes and other structures in thefloodplain to take tions on resale value than with the effect of a potential flood on the house or outflood insurance. This procedure has not been property itself Some studies have found that even after a control structure is wholly effective because the institutions currento are built, local governments remain concerned about a flood problem, while the not penalized tf theyfail to comply. citizens themselves tend to forget about the threat. Both individual and com- munity perception of risk may be tempered by other considerations, such as apprehension about the potential secondary effects of land use management- Precious page.. Charks River watershed, Massachusetts. reduction in property values, slowed economic growth and development, I reduction in the tax base, and increased construction costs. 52 Informing and educating the public about both flood risk and about the importance of the natural and cultural resources of floodplains is an ongoing effort. Much research has examined ways to provide information and to make people take action, and new techniques are being sought continually. Typical means of providing information to the public include distribution of pam- phlets and other publications; use of radio, television, and newspapers; place- ment of warning signs; and many other more imaginative methods. A few jurisdictions require real estate agents to provide flood and other hazard information to prospective buyers of homes. Awareness of the Value of Natural Floodplains The protection of the natural and cultural resources of floodplains is beginning to emerge as a popularly expressed environmental objective; it is already encompassed in the broader environmental goals embraced through- PUBLIC SUPPORT FOR WETLANDS out the nation. The general level of public environmental awareness and sup- Concern for the Ivss of wetlands and supportfor their port for all types of protection programs has increased dramatically in the protection appear to be increasing. A 1982 Harris past 25 years, and the importance of preserving wetlands, protecting endan- pollfound that 8317o of respondentsfelt that it is gered species, and maintaining water quality is widely recognized. "very important" to preserve the nation's remaining This kind of awareness represents a potentially broad base of public sup- wellands. A 1985 poll reaffirmed this broad sup- port for floodplain management. Unfortunately, this voiced support does not port: 85 To of those polledfavored strict enforcement necessarily translate into action, particularly when an individual's own prop- of the Clean Water Act and its wetlands protection erty is involved. Any restriction on individual property rights may be strongly requirements. resisted, or the loss of natural values may seem inconsequential because of the small area affected. Protecting the Environment Percentage of the U.S. population that agreed with the following statement: Protecting the environment is so important that 90 requirements and standards cannot be too high and '00@ continued environmental improvements must be made 80 regardless of cost. 70 60- a) L) 50- 40- 30- 20- 10- 0 1981 1984 1986 Year 73 METEOROLOGICAL DATA: THE NWS Knowledge, Standards, and Technology The collection and analysis of weather data for Effective floodplain management requires a sound understanding of the floodplain management-precipitation intensity, physical, biological, and chemical processes that affect flood hazards and extent, and duration; wind data; and temperature- the natural resources of floodplains, as well as an appreciation of the social is the responsibi&y of the National Weather Servi@e. processes involved in human interaction with them. The last 25 years have The NWSs d2ta collection system extends through- witnessed a rapid expansion of the knowledge, information base, and techno- out the 50 states, offshore, and across the Pacific logical expertise in floodplain management-products of the combined efforts Ocean, and now consists of about 230 staffed stations, of governments at all levels, academic institutions, and the private sector. 165 automated stations, and almost 400 stations under contract. In marine locations, automated moored and drifting data buoys are used A network Climate Change and Weather Forecasting of automatic hydrological observing system stations is One of the basic assumptions of hydrology and floodplain management operated to provide near real-time data of river stages has been that long-term climate is constant. Over the past few decades, how- and rainfall. The NWS also operates 128 weather ever, new evidence has suggested that climatic changes can take place rather radar stations that provide information an areal quickly (over a decade or so) and last for half a century or more. Therefore, coverage, height, intensity, and rnovement of storms the traditional 30-year averages of various climatic parameters- precipitation, for warning andforecasting and hydrological and for example-that have been the basis of past policy may be misleading for climatological programs. Over 1,300 ships report data systematically, and 300 others report d2ta decisions involving long-term consequences. whenever they are in waters covered by NWSjore- During the 1970s and 1980s, indications of a global warming trend casts. increased, and some scientists hypothesized that human use of fossil fuels was amplifying the greenhouse effect sufficiently to cause changes in global climate. The normal historical relative rise in sea level is expected to continue over the next century, and as a result of the human-induced climate changes, the rate of rise is anticipated to increase. The predicted rise in global mean sea level is about 20 cm by 2030, and 65 cm by the end of the next century, with sig- nificant regional variations. This could have profound flooding implications. Streamflow Data Over 90% of the 7,492 daily-record stream gages in the United States are operated by the U.S. Geological Survey in cooperation with a local spon- sor. Since the first stream gage was established in 1889, the U.S. Geological Survey network expanded until 1980, but has declined since then, largely due to reductions in funding by local cooperators. This makes spatial and tem- poral consistency in gathering these data difficult. Even though information about runoff from small watersheds (between one and two square miles) is important for many purposes, including highway drainage design and urban drainage analysis, almost all of the nation's stream gages are located on larger watersheds. To partially fill this gap, the Agricultural Research Service has gaged hundreds of plot-sized watersheds to measure runoff for individual land uses and soils. HYDROLOGICAL DATA: THE USGS Hydrology and Hydraulics AND THE EPA Hydrologic parameters of importance to floodplain management are Water data have been published annual@y by the flood peak flows; flood volumes; time of concentration and travel; rate of rise; US. Geological Survey since 1890. Records are water velocities; sedimentation and degradation of flood channels and flood- now published annual@jbr each state and main- plains; flood elevations; the effect of geomorphology on floods and vice versa; tained on a computerized data base, the National the hydraulics of flood channels, floodplains, and human-made structures; Water Data Storage and Retrieval System. It and water quality as affected by floods. These characteristics and their inter- includes data from USGS surface water records, relationships are generally modeled mathematically. with an indexfor the 320,000 water data storage Inexpensive, easy-to-use computers have made it possible to apply sites; over 240 million dai@ parameters such as accepted methods of hydrology and hydraulics analysis to many floodplain streamflow, groundwater levels, specjti'c conductance, and water temperatures; 460,000 records of annual management activities. The susceptibility to flooding of small developments maximum streanfow and gage height values; 2.3 and even single structures now can be evaluated relatively quickly and inex- million analytical results describing biological, chem- pensively. Researchers and a few practitioners are using two- and three- ical, and physical water characteristics,- and construc- dimensional analyses of flood flows to obtain more realistic and reliable results tion history, geohydrologk data, and one-timefield than those yielded by the step-backwater analysis. Several models and methods measurements on 850, 000 sites. The Environmental are available for mapping the 100-year flood in coastal areas, for determining Protection Agency has a water quality data base of stillwater flood elevation from hurricanes along the Atlantic and Gulf coasts, nationwide information on water qualiy, water and for accounting for the effects of wave heights, wave runup, and marsh qualio standard@, point-source pollution, fish kills, grass. Other models address flooding on the Great Lakes, flooding from waste abatement needs, and other topics. tsunamis, and other special situations. Sediment transport models are being 54 1 developed, calibrated, and applied in many areas. All these techniques, which A COMPUTER MODELS FOR HYDROLOGY AND HYDRAULICS Computer programs like the Soil Conservation Serv- ice's TR-20 and the US. Arny Corps of Engi- neers' HEC-I can be used to mathematically model hydrologic conditions based on such parameters as flood peaks, volumes, rate of rise, and velocity. Other programs in use today are the Soil Conserva A tion Service's TR-55for small urban drainages and the Environmental Protection Agency's SWAIMfor urban drainages where water qualio is important. To determine a water-surlace elevation for a single point on a stream, the Manning equation is often used and can give good results where normalflow prevails and there are no downstream obstructions. However, when there are obstructions or other special In recentyears, microcomputers have made it possiblefor agencies andjurisdu@ons at all levels to use conditions, a backwater analysis is used, and com- sophisticated hydrologic and hydraulic models to analyze potential flooding at virtualo any scale. puter models have been developed to perform it as Microcomputer workstation at the Floodolain Management Section, Louisiana Department of Transportation well. The most widely used backwater model is the and Development. Corps'HEC-2. A special dynamic routing model has been developed by the National Weather Service only a decade ago were very expensive and hence infrequently applied, help forflood routing and inundation from dam breaks. evaluate the effects of future urbanization, structures, and other land use The NWS also developed thefirst widely applied changes. Although the computer revolution has improved many aspects of model, known as SPLASH, for early mapping of flood hydrology and hydraulics, it has also made possible misuse of the stan- coastalflood zones under the National Flood Insur- dardized techniques by those not fully aware of the assumptions and limits ance Program. A more sophisticated model, SLOSH inherent in the methods. (Sea, Lake, and Overland Surgefrom Hurricanes), was developed in 1975 to modelflood levels at the Flood Forecasting and Warning coastlinefor hurricanes of a particular magnitude, forward speed, and track. Today, the Coastal Weather forecasting, and hence flood forecasting, is improving with Flooding Hurricane Storm Surge Model is used remote sensing capabilities and the availability of more real-time data. New by the Federal Emergency Management Agency to radar equipment, such as NEXRAD, and other tools promise better precipi- analyze coastalflood hazards. tation forecasts for small-scale storms and flood forecasting for small water- sheds. The combination of new satellite data on snow pack and real-time data on precipitation and temperatures may be combined with established runoff models and recurrence interval techniques to produce seasonal flood forecasts. There are a small number of automated flash flood warning systems throughout the country, notably in Arizona, California, Colorado, Connecti- cut, Maryland, Nevada, New York, Pennsylvania, and Texas. The performance kN1 of these systems has been uneven; most have not been tested under actual flooding situations to determine if they will indeed provide the anticipated level of warning. As the technology improves and operation and maintenance experience is gained, additional automated systems will come into use, signifi- cantly reducing the loss of life from flash floods. Soil Identification and Mapping Soil maps and data have proven useful in identifying and classifying floodplains and wetlands. The modem soil survey, with improved techniques and standards, began in the mid-1950s. By 1983, the Soil Conservation Service had mapped and classified about two-thirds of the U.S. land area (except Alaska), or nearly 1.3 billion acres. The Soil Conservation Service expects to complete soil surveys for the entire country by 2000. The agency is beginning 4 .4 to digitize existing soil surveys, and most of the remaining soil survey maps A. may be prepared with digital methods at the outset. This should improve the level of detail of soil classifications, standardize the map scales, and provide V additional supporting information. I ?A1_11 My A" Warning siren tied toflood sensors, Lavaca River, near Hallettsville, Texas. 75 Mapping Flood Hazards Nationwide mapping of floodprone areas may well be the single great- est achievement in floodplain management to date. Before enactment of the National Flood Insurance Act, floodplain mapping was done through the programs of the Corps, the Sod Conservation Service, the U.S. Geological Survey, and the Tennessee Valley Authority. Each agency mapped floodplains according to its individual authority and primary mission, and often on a project-by-project basis or only after major floods. The Corps compiled a national list of incorporated communities with flood problems and in 1962 began mapping and providing the information to individual communities in floodplain information reports. Mapping of floodplains for the National Flood THE COST OF FLOOD MAPS Insurance Program began in 1968, when the Federal Insurance Administra- The Federal Insurance Administration now spends tion began producing temporary maps to show approximate boundaries of about $36 million annually to keep publishedflood floodprone areas in identified communities and entered into cooperative risk information updated and current and to provide efforts with other federal agencies and contracts with private engineering detailedflood risk data where none existed before. firms to develop methods for preparing more detailed maps. By 1990 more Of this amount, about $4 million annually is spent than 12,000 new flood insurance map studies had been initiated and over to distribute about seven million maps to states, 1,700 restudies undertaken at a cost of nearly $900 million. In addition to communities, lenders, agents, banks, consultants, contracting with numerous private firms, the Federal Insurance Administra- and others. tion used the resources of the Corps, the U.S. Geological Survey, the Soil Conservation Service, the Tennessee Valley Authority, the Bureau of Reclama- tion, the National Oceanic and Atmospheric Administration, the Delaware River Basin Commission and the Susquehanna River Basin Commission, and some states to perform this work. Twenty-three states fund and prepare their own floodplain maps to com- plement the National Flood Insurance Program-to provide greater detail or a better scale, to reflect changes in development or hydrology, to extend map- ping beyond corporate limits, to meet special requirements, or to cover special natural values. In the past few years, communities themselves have become more involved in mapping, either because of unique floodplain problems or because comprehensive local programs require more specialized mapping. In addition, private consultants frequently perform hydrological or drainage studies for subdivisions and other developments. These studies form the basis for many amendments and revisions to original flood insurance maps. MV Sr WA), t AY a,- Cn 0 *1 CCW,400ft 52 0 The foundation of the Nationd Flood Insurance Program is accurate maps of hazard areas in j7oodprone communities. The program has been producing such maps since its inception in 1968 Flood Boundary and Floodway Map of the Fishkill, New York, area. 56 Understanding and Mapping Wetlands Since the 1970s significant progress has been made in both scientific and public awareness of the value of wetlands. In 1986 the Environmental Protec- tion Agency adopted a plan of research on ways to create, restore, and enhance wetlands and their functions. National wetlands mapping is being performed by the U.S. Fish and Wildlife Service. The detailed (scale 1:24,000) wetland maps are used by local, state, and federal agencies and private organizations for many purposes, including comprehensive resource management plans, environmental impact assessments, pen-nit reviews, facility and corridor siting, oil and chemical spill contingency plans, natural resource inventories, and wild- life surveys. They show the location, shape, and characteristics of wetlands and deepwater habitats on a U.S. Geological Survey base. Wetlands are clas- sified according to the Fish and Wildlife Service's wetland classification system. Maps have been done for 6517c of the lower 48 states and 20% of Alaska. In addition, many states have developed their own wetlands mapping programs. Understanding Natural and Cultural Resources As discussed in Part II, the nation's floodplains contain some of its most important natural and cultural resources. A wide variety of data sources now provides information about these national assets. For example, the U.S. Environmental Protection Agency maintains several dozen water-quality- related data bases, and the U.S. Geological Survey compiles extensive natural resources data through its Water Data Storage and Retrieval System and the National Water Data Exchange. Additionally, the U.S. Fish and Wildlife Service, as part of its National Wetlands Inventory, is developing a computer- ized multidimensional wetlands mapping scheme for the entire country. The U.S. National Park Service has established the Nationwide Rivers Inventory of more than 1,500 river segments and maintains much other data on both natural and cultural resources. NOAA's National Ocean Service and National Marine and Fisheries Service maintain natural resources data in several data bases as part of NOAA's responsibilities as the nation's principal marine science agency. The Soil Conservation Service oversees the National Resources Inventory-a survey of land use and quality, based on 160-acre units across the United States-and the U.S. Forest Service similarly keeps extensive information on lands within the national forest system. Beyond these federal resources, state agencies, private organizations, and universities also maintain comprehensive data describing many aspects of the nation's cultural and natural resources. Remote Sensing Techniques In the past 20 years the availability and analysis of high-altitude pho- tography, satellite imagery, and other forms of remote sensing have increased tremendously. Systematic comparison of images from different times yields information on changes in land use, which can be used to help assess many natural resources and identify areas where future flood damages may occur. After the land uses and natural resources of an area are calibrated, most of the subsequent analysis can be automated. So far these techniques have had limited application in relatively small areas of the nation's floodplains, but technological advances in computer capabilities and data management systems HENDERSON COUNTY'S GIS should accelerate the use of remotely sensed data in the near future. The Henderson County, North Carolina Soil and At least one Arizona community uses periodic aerial observations to look Water Conservation District is one of thefirst in the for floodplain violations. Aerial photography combined with floodplain maps nation to install a microcomputer-based geogrqphi@ has been used in some communities to count the number of structures within in f@rmation system to provide better interpretative selected floodplains. Other communities have used or plan to use low-level soils information. The county's published soil survey aerial photography after floods to help determine the extent of flooding and has been digitized and stored in the system, and the damage. As digital mapping becomes more widespread, it will become easier computer can capture, store, ana0ze, and retrieve and more inexpensive to monitor floodplain activities through remote sensing. soils maps and other geographic d2ta. Fundingfor the &-monstration project was provi&d by the Ten- nessee Valley Authority, supplemented hy the Soil Geographic Information Systems Conservation Service and the Henderson County Many organizations now make routine use of geographic information Commissioners. systems (GIS)-computer systems that allow users to collect, manage, and analyze large volumes of spatially referenced and associated attribute data- 57 for a wide variety of purposes, including natural hazards and natural resource management. GIS-generated maps are easily manipulated and can be up- dated at a low cost. However, GISs have not yet become widely used, mostly because the initial cost of digitizing the needed information for input into a GIS system can be formidable. Another handicap is that the different systems now in use are not always compatible. Once these obstacles are overcome, GIS technology will allow planners and managers to more easily obtain and apply the information they need to make wise decisions about floodplains. The Federal Emergency Management Agency is developing a standard for digital flood insurance maps in public domain format and has committed to a program to digitize the maps for over 340 metropolitan counties with large amounts of property at risk from flooding. Regulatory and Design Standards Over the past 20 years numerous standards of terminology, procedure, performance, and quality have been developed in floodplain management. They include both prescriptive standards (clear-y identified limits set by law, policy, or custom), and performance standards (requirements that a specified goal be reached by unspecified means). Some of these standards are freely adopted, others are met in response to an incentive, and still others are required by law. Many manuals and technical reference volumes have been developed to assist builders and regulators to meet the performance standards required by the National Flood Insurance Program. Having these standards has provided a uniform means of applying, reviewing, and evaluating the design, construction, and regulation carried out in support of floodplain management. Not all aspects of floodplain management are amenable to nationwide standardization. There have been no national standards established for mini- mum setbacks from river channels, although there are some statewide stan- dards for designated streams, lakes, and other water bodies. Lincoln Township, Michigan, for example, requires setbacks of 110 feet from dune and bluff areas on Lake Michigan, while Wisconsin requires a minimum setback of 75 feet from the ordinary high-water mark. There are no national standards for dam and reservoir construction; instead, each federal agency has its own set of criteria. Likewise, each of the three agencies (the Corps, the Soil Conservation Service, and the Bureau of Reclamation) that constructs federally funded levees has its own policies for construction and maintenance. judicial Support for Floodplain Management AVOIDING CONSTITUTIONAL Over the last few decades the types of lawsuits and the specific issues liti- CHALLENGES TO REGULATIONS gated in floodplain management have changed, reflecting the predominant To reduce the chances of having theirfloodplain techniques of the time and general status of the relevant law. Before 1968, management regulations found unconstitutional, most litigation challenged the power of governments to undertake flood control many jurisdictions have measures and to regulate floodprone lands. From 1968 to 1978 concepts of legal 0 adopted regulations with stringent performance liability expanded and government defenses to it diminished. Constitutional standards rather than simpo prohibiting all challenges to regulations increased and shifted from broad constitutional activities in hazard areas; attacks to specific challenges to the reasonableness of particular measures. * mappedfloodplains in more detail and more Since then, courts have continued to hold governments liable for their actions accurateo than has the National Flood Insurance that increase flood damages. The number of constitutional challenges to Program; regulations has diminished, however, due to the widespread judicial support 9 provided real estate tax breaks for tightly con- for regulations over the previous 20 years. Most recent cases have addressed trolled land to diminish thefinancial burden of relatively technical issues, such as the validity of nonconforming use provi- owners whose use of their property is greatly sions and setbacks. restricted; improved their permitting and record-keeping Constitutionality of Regulations procedures to include detailed statements offind- Floodplain management regulations have been challenged as unconstitu- ings on denials in order to provide a better tional on two fronts: as violations of due process guarantees and as takings of defense in court. private property. The due process claims, which were based on a general legal argument that the federal, state, and local governments had no legal authority to regulate activities on floodplain lands and waters, have almost disappeared over the years as the statutory authority to regulate was clarified and strength- 58 ened. With the exception of a few cases in which regulations prevented all economic use of floodplain property, courts likewise have upheld the general validity of floodplain regulations against claims that they take private property AVOIDING LIABILITY FOR FLOOD for public use without payment of just compensation, in violation of the Fifth DAMAGES Amendment to the U.S. Constitution. These rulings are consistent with a There are many actions that state and local govern- much larger body of law in which courts have upheld other land use regula- ments can take to reduce their potential liability for tions against claims of taking, despite the impact of the regulation upon prop- flood damages: erty values. Floodplain management regulations have been supported for a Obtaining legal advice before taking anticipated number of reasons. actions,- 0 The rights of private landowners to their water-oriented lands are * adopting comprehensive flood hazard plans, subject to public trust and navigable servitude rights and interests. because they can avoid liability if they avoid 0 Courts give great weight to protection of public health and safety flood h=rds; and have, without exception, sustained regulations needed to prevent 0 enrolling in the National Flood Insurance Pro- nuisances (such as blockage of flood flows) and to prevent private gram, because landowners are less like@ to sue actions that may threaten public or private safety on other property for damages if they are insured and thus quickly (such as construction of dams). receive compensationfor their losses; 0 Over the past 20 years courts have upheld performance standards such * adopting drainage as well asj7ood hazard as the requirements that private landowners protect the floodway's con- reduction plans and regulations (most suits against veyance capacity and elevate or otherwise protect structures to the 100- cities Jorflood problems are really for damages year flood elevation. due to interference with natural drainage),- 0 Courts have supported technically based regulations adopted consistent * operatingflood loss reduction measures with a federal, state, or local overall plan and standards (pollution con- (structures, warning systems) with greater care trols or the National Flood Insurance Program, for example). to avoid claims of negligence; 6 avoiding hazardbrone locations for public Liability for Flood Damages facilities; In contrast with the small number of successful constitutional challenges * designing public works-roads, sewers, bridges, and water treatment facilities-to com- to governmental floodplain management actions over the last 20 years, land- p@y with federal, state, and localfloodplain owners have won thousands of damage suits against governmental units for guidelines and regulations so they d9 not block causing or increasing flood damages. Most of these have been based on such floodflows or cause drainage problems; common law grounds as nuisance or trespass. * Undertaking remedialflood loss reduction There have been more successful liability suits in recent years because measuresfor existingfloodprone development, � Large damage awards from juries (and subsequent payments of them particularly where the problem has been parto by governments with "deep pockets") have made plaintiffs and lawyers the result ofgovernment action,- more willing to litigate; *purchasing liability insurance and establishing � Courts have recognized broadened concepts of public and private land- seo' insurance pools. owner responsibility to other landowners and the public; � The "act of God" defense has diminished as a result of improved flood prediction capability and maps; � Improved data on stream flow and better hazard modeling have made proof of causation of the damages easier; � Improved technology, wider use of that technology, and adoption of regulations and guidelines have all raised the standard of "reasonable" actions on the part of government; and � The "sovereign immunity" defense of states and local governments, and to a lesser extent the federal government, has been modified by statutes and case law, making the governments responsible for more actions and their consequences. Avoiding Legal Problems There is little doubt that perform ance-oriented floodplain regulations (building codes, subdivision regulations, zoning, etc.) will continue to be upheld in the courts despite restrictions that may affect private property owners in some instances. Likewise, carefully crafted flood loss reduction measures will reduce community and state liability in the long run. It is important, however, that governments take care when formulating and implementing these measures to reduce potential legal problems and lessen the risk of constitutional challenge. 79 The Present and the Future Overview It is difficult to assess the effectiveness of floodplain management in the United States. The degree of accomlishment to date is impressive; at the same time, a considerable distance remains between the status quo and the ideal that can be envisioned. Two principal complications are that there are few clearly stated, measurable goals, and that there is not enough consistent, reliable data about program activities and their impacts to tell how much progress is being made in a given direction. Overall Effectiveness There is general agreement on three fronts: 0 Floodplain management should reduce the number of flood-related deaths in the nation. This goal has been partially achieved. Average Between 1916 and 1985, there were an average of annual loss of life from flooding has been somewhat reduced from the about 100flood- related deaths annually,- there is no level that prevailed early in this century and has remained relatively indication that deaths are increasing or decreasing on constant for many years. a per capita basis. 0 Floodplain management should result in an actual decline in the nation's flood losses, including public and private property damage, injuries, and disaster relief. This has not been achieved. In fact, there Per capita flood damages were alinost 2.5 times as was a definite increase in flood damages from 1916 to 1985, although greatfrom 1951 to 1985 as they wereftom 1916 there is evidence that these losses have remained fairly constant over through 1950, after adjustingfor inj7ation. the last two decades when compared to broad economic indicators like the GNP. * Floodplain management should reduce the loss of the natural and cul- tural resources of the nation's floodplains. The programs designed to The natural and cultural resources offloodplains are do this have not yet arrested that deterioration. being lost at unacceptable rates. Achievements to Date Several significant achievements in floodplain management can be noted, even though all the goals have not yet been reached. � There is now more widespread public recognition of flood hazards, the value of the cultural and natural resources of floodplains, and the close interrelationship of the hazards and the resources. � There is an extensive body ofjudicial decisions supporting floodplain management activities, indicating a perception throughout society that floodplain losses can and should be managed. � Numerous standards of terminology, procedures, performance, and quality have been developed, providing a uniform means of applying, reviewing, and evaluating the design, construction, and regulations needed for floodplain management, and also providing limited meas- ures of effectiveness. � In many locales, floodplain development has been prevented or reduced in high hazard areas as a result of mapping and the establish- ment and enforcement of regulations. � New development that meets commonly accepted flood-loss reduction standards has experienced greatly reduced losses. � The institutional framework for floodplain management has been improved through an expanded legislative base, new agencies, and sup- portive judicial interpretations. There has been a shift away from fed- eral dominance toward a more equal partnership among federal, state, and local governments, and the private sector. � A considerable amount of floodplain acreage, particularly wetlands, has been preserved by both the public and private sectors. 60 The Need for Specified Goals No single piece of legislation or other authority outlines a compre- hensive set of measurable goals and objectives for floodplain management in the United States. Floodplain management would benefit from a set of speci- fied goals meant to be achieved by a certain date and whose success can be measured. Numerous national goals have been proposed by various govern- ment agencies and observers of floodplain management. Some examples of these suggestions are managing the natural resources of floodplains in con- junction with loss reduction efforts by the year 2000; moving people out of areas where they are continuously threatened by flooding; removing all resi- dences and commercial establishments from the 20-year floodplain by the year 2020 and restoring these lands to their natural state; reducing losses to exist- ing buildings and infrastructure by requiring all federal agencies to assess the vulnerability to flooding of existing federal facilities and those state and local facilities constructed with federal aid; and reducing losses to areas and struc- tures outside regulated floodplams. The Need for a Comprehensive Data Base There is a considerable amount of information about floodplain manage- ment available, but most of it was not collected with evaluation in mind; thus it is not precise enough to support judgments about the effectiveness of vari- ous floodplain management activities. This not only inhibits evaluation, but GISs AND THE FLOODPLAIN also hinders legislators, regulators, and other professionals in their efforts to MANAGEMENT DATA BASE establish, overhaul, or fine-tune programs and strategies to make them more Recent advances in the development and application effective. A mor .e complete data base will also give local government leaders a ofgeographic information systems can improve the better opportunity to identify the public risks and costs associated with flood- floodplain management d2ta base. With these sys- plain development. tems, layers of information, such as thatfromflood The obstacles to developing and maintaining an adequate data base are insurance maps, cultural resource maps, and the substantial. Important determinations must be made about the type of data TIGER data system of the US. Census Bureau, to be collected, how often it should be collected, by whom, and using what can be combinedfor display, ana@sis, and manage- criteria. Adequate funding must be found. ment applications. Additional information should be developed on several important topics, including an examination of the full benefits and costs, both public and pri- vate, of floodplain occupancy; an evaluation of the monetary benefits of main- taining the natural uses of the floodplain; and a determination of the steps needed to reduce the potential losses in the areas of the nation with the highest risk of catastrophic impacts from flooding. The Effectiveness of Management Although a truly unified national program to manage floodplains is not yet in place, great strides have been made in that direction. The management framework has matured and expanded significantly since the 1960s. The growing recognition of the need for alternatives to federal investments in structural projects for flood loss reduction has been of particular importance. A major improvement was made in 1979, when protection of natural flood- plain resources was formally embraced. But the conceptual approach pre- sented in the current Unified National Program for Floodplain Management is still evolving. Further improvements could be made in the framework by develop- ing a clear definition of floodplain management and a set of measurable goals. Management efforts in general would be more effective if there were more flexibility for different approaches, smoother coordination among government agencies, and ways to account for local conditions. Allowing for Different Approaches Many floodplain losses are of a sort that simply cannot be addressed through a by-the-book approach. For example, management techniques for such high risk flood problems as ice jams, flash floods, coastal flooding and erosion, mudslides, ground failure, alluvial fans, fluctuating lake levels, move- able stream beds, and areas behind unsafe levees or below unsafe dams, are not included in most local programs, which are designed to meet standardized National Flood Insurance Program minimum criteria. New methods for iden- tifying, mapping, and regulating areas with these flood hazards have been developed in some states- particularly in the arid West-through special 61 cooperative efforts with the Federal Emergency Management Agency. This sort of flexible and innovative approach yields more effective management in the long run. Incentives for communities to map and regulate high risk hazard areas are now being provided through the Community Rating System of the National Flood Insurance Program. Another reason that management flexibility is needed is that the condi- tions that cause floods do not recognize the political boundaries by which most floodplain management techniques are applied. Many professionals believe that comprehensive management based on hydrologic units must be made a higher priority, especially if natural resources are to be protected. The river basin commissions, the Environmental Protection Agency's National Estua- rine Sanctuary Program, and the National Park Service's State and Local River Conservation Program are examples of this technique. To facilitate broader management, the states could enact legislation providing for regional or watershed management, for river corridor management, and for other regional efforts based on hydrologic and other natural boundaries rather than political jurisdictions. Coordination among Government Agencies There is more coordination and better cooperation among all levels of government now than there was 25 years ago, but improvements could still be made. Each government agency involved with floodplain management has its AGENCY AND ORGANIZATION own legislative mandate and in general, each has been diligent in carrying out COORDINATION that mandate within the imposed statutory limits. From the standpoint of an overall federal program for floodplain management, however, there are many Positive interagency coordination is exemplified by inconsistencies of purpose and procedure, overlaps, gaps, and conflicts. Some professional groups like the Association o State f of the inconsistencies can be reduced or eliminated by administrative action, Floodplain Managers and the Association of State but some conflicts result simply from differing attitudes and expectations Dam Safqy Officials, and bod2es like the Inter- agency Committee on Dam Safety. Federal, state, about the ultimate responsibility and commitment of resources to respond and local off@@ls, and representatives of the private to flood problems, and these are not likely to be readily resolved. Neverthe- sectorform the memberships of these groups, and they less, a spirit of cooperation and common purpose can smooth many conflicts have brought an important spirit of cooperation and and enhance existing efforts. coordination that has been of tremendous benefit to floodplain management over the past decade. They Providing for Local Conditions met formally once a year and coordinate throughout Prescribing uniform national standards for the preservation, use, and the year through subcommittee work- and special development of floodplains and other hazard areas for application at the local projects. level can be inefficient and result in social inequities. Many of the existing floodplain management tools are more easily applied in communities with fairly high standards of living, where the local government has adequate staff, resources, and expertise. This excludes many small rural communities and economically disadvantaged areas. Natural resource preservation is a bottom priority in low-income communities where a resident cannot even count on the availability of potable water or sanitary facilities during and after a flood. An awareness of local conditions could be incorporated into the national pro- gram through wider use of performance standards, provisions of the Commu- nity Rating System of the National Flood Insurance Program, and more flexi- bility in the application of requirements for a positive benefit/cost ratio for federal funding of flood control projects. 62 The Effectiveness of Floodplain Management Strategies and Tools Additional accomplishments could be achieved through better or more extensive use of the strategies and tools of floodplain management. Of the four strategies, modifying flooding has traditionally been the most popular because most of the planning, funding, construction, and implementation for structural measures is carried out by the state or federal government, and because local and individual adjustments or sacrifices are minimal. In contrast, many measures to modify susceptibility to flood damages or to modify the impacts of flooding are implemented on a structure-by-structure or property-by-property basis and require constant vigilance, personal incon- venience, and financial sacrifice. These drawbacks resulted in a lack of public support for such measures in the past, and consequently local governments were often reluctant to impose or enforce them. By the mid-1980s, however, this impediment had been largely overcome and local officials began to focus on how to comply with federal and state requirements and administer com- munity programs to manage floodplains. Measures to modify susceptibility to flood damage and disruption and to modify the impacts of flooding are now widely accepted, even though some communities still have difficulty administering them. The strategy of restoring and preserving the natural and cultural resources of floodplains has had little exposure to date and needs to be better integrated with the other strategies, both conceptually and in practice. Modifying Susceptibility to Flood Damage and Disruption The tools used for this strategy have enjoyed widespread, fairly successful implementation. Susceptibility to flooding in the United States is constantly being effectively lessened at individual and local levels through the use of regu- REDUCING LOSSES THROUGH lations, development policies, programs for disaster preparedness and assistance, WARNING SYSTEMS and warning systems. Evidence indicates, however, that overall vulnerability Annualflood damages in the Connecticut River has either increased or stayed the same, probably because of the large amount Basin were reduced by $750,000 with aflood of vulnerable development already in place, numerous exceptions to the state warning system that cost about $250,000 annual@. and local policies that would reduce that development, and the fact that popu- lation growth, movement, and urbanization sometimes take place so quickJy or in such unexpected ways that adequate planning and regulation simply cannot be established soon enough to prevent unwise use of floodplain areas. This strategy may have the most potential for widespread future use, however, because its tools can be coordinated well with other strategies and because it provides an ongoing, more enduring way of adjusting to the flood hazard- that is, altering human behavior usually before the losses occur. Improvements could be made in the implementation of this strategy by a improving the enforcement of floodplain regulations by local governments; 0 reducing the usually unfounded concern of local and state officials that strict floodplain regulations will be challenged as unconstitutional tak- ings of private property; FLOOD CONTROL INVESTMENT AND RETURN 0 minimizing flood damage to existing infrastructure and properly The federal government spent over $13 billion for designing and regulating future infrastructure that must be located in dams and otherflood control structures between or near the floodplain; and 1936 and 1975. About $360 million had been 0 ensuring that current disaster assistance policies do not undermine expended on shoreline protection studies and projects long-range floodplain management efforts. by 1985. In returnfor these investments, billions of dollars in property damage have been avoided and Modifying Flooding hundreds of thousands of people have been protected National efforts to modify flooding have probably been more successful from anxiey, injury, and death. than those directed toward any other strategy. The approach of controlling floods is older than the other strategies, and over the course of five or six decades countless floodprone situations have been alleviated with struc- tural measures. There is increasing recognition that the strategy of modifying flooding can be counterproductive in at least two ways. First, it has been suggested that the creation of structural protective works encourages development in the 63 protected" area, resulting in increased vulnerability, perhaps not to the design flood, but to larger ones or to unforeseen catastrophic events like struc- tural failure. Second, structural measures can have adverse impacts on wildlife habitat, scenic resources, and water quality, thus undercutting other flood- plain management strategies. Partly as a result of these concerns, there has been a considerable shift away from reliance on structural solutions since the early 1960s. The planning and installation of measures to modify floods, however, have not been aban- doned. Flood control projects are still needed to complement the application of other floodplain management strategies, particularly to protect existing development. There is an opportunity now to reformulate this strategy to acknowl- edge its relationship to other techniques. Some of the tools to implement this strategy, such as land treatment measures, on-site detention, and shoreline protection, can be important components of comprehensive floodplain management and resource protection programs. Modifying the Impact of Flooding on Individuals and the Community The impacts of flooding on individuals and communities have definitely been modified over the last 25 years, largely through increased awareness of flood hazards as a result of the provision of information and education, and because of the availability of flood insurance. After many years of counter- productive effects, two of the tools for this strategy have recently undergone basic revisions that may make them more effective at reducing future losses: tax adjustments for flood losses have been reduced, and postflood recovery measures designed to minimize future losses have been determined to be THE EXTENT OF THE NFIP an appropriate use of disaster assistance funds. As of 1990, 82% of the nation's 20,000floodprone The implementation of this strategy could be improved by communities hadjoined the National Flood Insur- 0 expanding individual awareness of and knowledge about floodplains; ance Program. In 1990, 2.39 millionflood insur- 0 improving training programs for code administrators, planners, inspec- ance policies were in force, proz. iding ozer S200 bil- tors, public works directors, and other local government personnel lion in coverage. From 1978 to 1989, oier 384,000 flood damage claims had been paid, totalling about directly involved in floodplain management; $3. 1 billion. * enlarging the premium base by increasing the number of insured structures, and thereby moving the National Flood Insurance Program closer to a fully actuarial basis; and 0 ensuring that postdisaster mitigation funds are used completely and creatively. Restoring and Preserving the Natural and Cultural Resources of Floodplains As the latest addition to the array of floodplain management strategies and the one least well-integrated with the others, it is not surprising that this strategy has met with limited success. Floodplain land is being preserved in a limited way through acquisition, public understanding and support for pres- ervation and restoration of natural resources is growing, and mapping of the PROTECTING RIVERS FROM nation's wetlands is more than half finished. These accomplishments, how- ALTERATION ever, have been the result largely of programs, policies, and efforts outside As of 1990, 9,351 miles on 123 of the nation's the floodplain management arena. Regulations to protect and manage natural rivers had been designated as wild or scenic, and resources in general are not well coordinated with those to reduce flood losses, therefore protected underfederal law. But these pro- resulting in conflicts when implementation and enforcement are at stake. The tected stretches are greatly outnumbered by the stream strategy itself needs to be better integrated both with other floodplain manage- segments that would be altered by proposed dams, ment tools and strategies and with compatible efforts in other fields, such as channel modifications, and other projects. river corridor management, endangered species protection, and nonpoint pollution control programs. 64 INTEGRATING FLOOD LOSS REDUCTION AND NATURAL RESOURCE PROTECTION Most localflood loss reduction programs focus primarily on the 100-yearfloodplain, while natural resource protection programs focus on a particular resource (wetlands, for example) which rwy or may not be located in thefloodplain. The two types of programs also are triggered by different events. Dis- a section 404 aster relief is provided after a flood, permit is required when dredging orfilling is @A planned; a wild and scenic river study begins after A, Congressional action. These basic differences make integration of the programs difficult. The restoration and preservation of floodplains as natural resources is largely the result of efforts that are not well coordinated with the principal programs of)7oodplain managernent. Floodplain, Wildcat Falls, Joyce Ki&ner Memorial Forest, North Carolina. Conclusion Over the past 25 years, floodplain management has matured from a focus on reducing flood losses by using structural measures to a broader approach that incorporates structural and nonstructural measures for flood loss reduct 'on and also takes into consideration the protection of the natural and cultural resources of floodplains. The examples of flood damages averted, lives saved, and resources preserved are plentiful. It is evident that substantial progress has been made, and that diligent work is underway to remedy past shortcom- ings and reach even greater levels of achievement. If current trends continue, the near future will see a further broadening of the scope of floodplain management to encompass such activities as storm- water management, greenway and river corridor management, and watershed management. Further integration of individual strategies and tools is likely, so that a more unified floodplain management program can emerge, with fewer conflicts among goals and activities. Technological advances also promise the improved application of existing strategies and tools. A number of important opportunities are emerging for improving the future effectiveness of floodplain management in the United States. This report on the nation's floodplain management activities-the first compre- hensive assessment in over 25 years-has identified a plethora of actions to be pursued if significant improvements are to be made in floodplain manage- ment in the coming decade. Of these, two stand paramount: a simplification of the concept of floodplain management, and a set of specific national goals with a timetable for their achievement. These two needs should be addressed as the Federal Interagency Floodplain Managment Task Force undertakes to further refine the Unif@ed National Program for Floodplam Management. 65 RETROSPECT AND PROSPECT -an invited conwwnt by Gilbert E White This Assessment is unprecedented in its depth of analysis of the nature and effectiveness of the nation's management of floodplains. It is the most detailed and nearly comprehensive of all studies of those matters since the concept of floodplain management took official root in the mid-1960s. It places that con- cept in a broader context than ever before, and it provides a base for launch- ing a series of steps to assure that local and state as well as federal programs can at last approach the aspirations that have evolved over the past 65 years. That evolutionary process has been reflected in a stream of laws, executive orders, regulations, new groups, and reports. Debate over the wisdom of reli- ance on simple levees and channel modifications began in the wake of the 1927 flood on the Lower Mississippi. It widened to include issues of dams and economic justification after the Ohio River floods of 1936 and 1938 and a concurrent upstream versus downstream controversy over land treatment. By 1966 a still broader view of the potential role of nonstructural measures found favor. Then followed a series of revisions and expansions of federal and state activities. Those included the National Flood Insurance Act of 1968, a National Science Foundation appraisal of flood research in 1977, a UnIfLed Natwnal Prograrnfor Floodplain Managermni in 1976, with revisions in 1979 and 1986, three Executive Orders, a formal linkage with emergency management programs, and the organization of vigorous nongovernment groups such as the Association of State Floodplain Managers and the Association of State Wetland Managers. All of this and much more is examined in the Assess- ment. To sum up, the report tells the country what has been happening in floodplain management; how well or how poorly the responsible federal and state agencies have been doing; and what are promising means of improving the prospect. The result is the first thorough appraisal of ambiguous national aims and how those compare with the present situation on the lands at risk- the diverse areas of watercourses, adjacent wetlands, and the shores of streams, lakes, and oceans. The report candidly recognizes the severe handicaps of incomplete and inconsistent collection of data on which policy judgments must be based. The data base is the one need specified in the 1966 House Document on which almost no action has been taken. For other needs, the record of change has been diverse but generally posi- tive. In no instance, however, has achievement matched the hopes of earlier years. The definition of precisely what is meant by floodplain management in particular areas of the country or under the jurisdiction of specific agencies is still far from clear or uniform in either principle or practice. The policy goals for the sustainable use of floodplains have progressed in agency thinking but are proving difficult to meet in operation in the field. It has not been made clear how floodplain use is inseparably linked to the maintenance of natural resources for the common good for the foreseeable future. The effectiveness of individual federal and state programs, each with a different statutory authority, suffers thereby. Cooperation among the administrators of federal programs, while generally cordial and helpful, has not yet yielded a genuinely unified effort. Lacking exemplary effectiveness at that level, state and local agencies cannot be expected to act in concord in meeting national goals. Great gains have been made in public information and education. Far more legislators, administrators, business executives, farmers, householders, and school children are aware of flood hazards than a decade ago. The level and quality of information, however, still is far below what would be required to induce effective action in the event of a threatening flood, and even more so in the days when measures are needed to mitigate future emergencies. Flood forecasting precision has generally improved. The demonstrated ability of communities to respond positively to a warning is less certain and is uneven. 67 The report suggests lines along which improvement can be brought about and recommends consideration of a number of changes in policy and proce- dure. The report's Review Committee does likewise with its Act in Agenda for Managing the Nation's Floodplains. These must be examined now against the back- ground of experience with previous statements of optimal floodplain policy, such as House Document 465 or the Unifi6d Natiqn@ Program for Floodplain Management. Only fragments of those proposals were adopted. Can anything be learned from the conditions that either promoted or blocked them? What are the factors in climate of public opinion and in government organization that worked for or against them at that time and that may have changed subsequently? It is evident that the reconciliation of thinking among professional groups, for example, has been advanced by research, conferences, training, and publi- cations. Hydrologists, engineers, geographers, economists, land planners, ecologists, city managers, insurance executives, and disaster relief directors, among others, now are speaking the same language. But there are at least three directions in which lessons learned are still not practiced. One important lesson is that quick and nation-wide change in procedures without careful trial in selected areas and without subsequent critical appraisal can be counter-productive. When the Tennessee Valley Authority established its community assistance program for flood damage prevention planning in 1953 and the Corps of Engineers introduced its floodplain management services program in 1960, they moved cautiously and employed a variety of trial approaches. In contrast, when national flood insurance was introduced in 1968 there was a brave commitment to offer coverage to all parts of the country at once. Little attention was given to post-audits of the rates, terms of insurance, map adequacy, and relation of detailed regulations to local physical and social conditions. As a result, the Federal Insurance Administration found itself locked into sometimes unwieldy or ineffective procedures that might well have been avoided in the light of experimentation. The attempt in the late 1970s to set up a nation-wide floodplain map file was likewise an unfortunately hasty enterprise. In its 23 years of operations, the National Flood Insurance Program has achieved much and continues to gain new experience. The current implementation of the Community Rating Sys@ tem now offers special opportunities to appraise the suitability of national standards and procedures at the local level. As new improvements are made in federal programs, it will be important to craft them on an experimental basis with careful provision for evaluation as they are launched. A second lesson derives from the contrast over the years between expres- sions of desirable unified policy and measures to, in practice, unify the activi- ties of agencies which in theory subscribe to the policy. There has been nei- ther a single statement of Congressional intent with respect to floodplain management similar to the Earthquake Hazards Reduction Act of 1977, nor a delegation to a single executive agency of responsibility for coordination of the various federal programs. The Bureau of the Budget was interested in such coordination in the mid-1960s but did not take a strong hand. The Water Resources Council served as a meeting place of interested agencies without having statutory authority. After the council disbanded in 1982 it was followed by the Interagency Task Force, a voluntary group that also lacked authority to enforce desirable action as outlined in three Executive Orders. It cannot be expected that conscientious administrators will abandon their own statutory authority and responsibility before joining cooperative ventures, no matter how desirable the goals. It is just as clear that unless a strong statement is made by the Congress on the ways in which the basic policies of the individ- ual federal agencies are to be related to the underlying aims in managing floodplain resources, those policies will have little significance in the field, where they influence or are constrained by state and local practices. The third major lesson is that floodplain policy changes must be taken in the context of broad environmental goals applied to local conditions. This was the case in the unfolding of the Coastal Zone Management Act where four federal agencies have joined in a partnership for action on habitat protection, nonpoint source pollution management, and sediment control. It occurs in the implementation of soil conservation programs on lands where environ- 68 mental integrity must harmonize with economic considerations. It is acutely the case in the delineation of wetlands, where the rigidity of proposed national criteria confronts wide variety in interpretation of suitable floodplain use. Coastal erosion raises similar issues. The reconciliation of multiple and some- times inconsistent national goals is an endemic problem in resource manage- ment. It can only be achieved effectively by dealing with particular landscapes in particular regions. When national goals shift or are clarified, as they surely will, the complexity increases. Unless floodplain management practices take into account local food and fiber production, biota, water supply, urban land use, recreation, and more-in addition to flood loss reduction-the goals for maintaining the sustainability of floodplains will surely not be met. Experience over the past 25 years suggests that to help achieve the improve- ments in prospect will require a willingness to test and appraise new pro- grams, a Congressional definition of unified federal policy, an executive decl- sion to assure the coordination of the federal agencies, and a commitment by representatives of the principal state, local, and nongovernment groups to col- laborate in adapting national aims to local conditions where the benefits will be seen-on the borders of the nation's rivers, lakes, and coasts. Without these measures, the resources of those areas will remain unduly vulnerable to natural extremes in stream flows and tides, and the people of this nation will receive less than optimal benefits from floodplains' amenities, soil, water, and biota. Gilbert E While has been observing the nation's floodplains for over 50years. He is a Distinguished Service Proftysor Enwritus of Geography and thefounder andformer director of the Natural Hazard@ Research and Applications Information Center at the University of Colorado. He was chair of the Task Force on Federal Flood Control Polky, 1965-66, and of the National Review Committee established in 1989 to assist in carrying out the assessment surnmarized in this volume. 10 79 Photo Credits. Cox=Bob Cox, Floodplain Management Section, Louisiana Department of Transportation and Development Corps= U. S. Army Corps of Engineers EPA= US Environmental Protection Agency TVA=Tennessee Valley Authority FEMA=Federal Emergency Management Agency NHRAIC=Natural Hazard Research and Applications Information Center Note. -Many of the photographs credited to the TVA were originally provided by other federal and state agencies to the TVA for presentations by that agency. Wherever possible, additional credit is given; in some cases, however, the original donor could not be determined. p. 7 John McShane, FEMA; pp. 9-10 (all photos), Cox; p. 11 (top right), EPA; p. 11 (bottom right), Merrimack River Watershed Council; p. 11 (left), Cox, p 12 (right and bottom left), Cox; p. 12 (top left), NHRAIC; p.13 (top), Colorado Department of Disaster Emergency Services; p.13 (bottom), TVAIArizona Department of Water Resources; p.14, (top), Cox; p.14 (middle), Corps; p.14 (bottom), TVAISouth Carolina Water Resources Commission; p.15 (right), TVA/California Department of Water Resources; p.15 (left), TVAIWashington State Department of Ecology; p. 16, Corps; p. 17 (left and right), Corps; p 18 (top), NHRAIC p.18 (middle), Cox; p.18 (bottom), TVAIMassachusetts Division of Water Resources; p.19 (top), TVA, p. 19 (bottom), TVA/EPA; p. 20 (top right), Cox, p. 20 (top left), TVA/Massachusetts Division of Water Resources; p. 20 (bottom left), Cox; p. 21 (top right), Cox; p 21 (bottom right), EPA; p. 23 TVA/Corps; p.24 (both photos), NHRAIC/Corps-Pittsburgh Office; p.26 Cox; p.34, Corps-Vicksburg Office; p.35, Corps-Vicksburg Office; p.37 Corps; p.38, TVA/Utah Department of Public Safety; p.39, TVA /Massachusetts Division of Water Resources, p.40, NHRAIC, p.43 (top), Corps; p.43 (bottom), TVA/Utah Department of Public Safety; p.44, Cox; p.45, EPA; p.47 Corps; p.48, TIA; p.51, Corps; p.52, FEMA p55 (top), Cox; P.55 (bottom), TVA/Texas Water Commission; P.56, FEMA; p.65, Cox. Back cover: Illustration of some flood consequences and floodplain management measures. Clockwise from top. 1. Flood water detention. 2. Regulations and development policies. 3. Information. 4. Coastal protection. 5. Flood emergency measures. 6 Natural protection systems, 7 Preserving natural resources. 8. Mapping flood hazard areas. 9. Structural elevation. Illompmr,mg; im CAMAGED 0 PRC)PERTY 'v a 000 A7-10NAL FLO01) o= Ck@ A F FIA-1 7May 1992 36661 3