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Coastal Zone Information Center Flood Hazard Mitigation Plan for Port ions of Coastal Flood Plain of Rio de La Plata COASTAL ZONE INFORMATION CENTER Seplember 1980 DEPARTMENT OF NATURAL RESOURCES TC 556.5 .P84 1980 FLOOD HAZARD MITIGATION PLAN FOR PORTIONS OF THE COASTAL FLOODPLAIN OF RIO DE LA PLATA September 1980 ICA- Financial assistance provided in part by the Coastal Zone MAnagement Act of DEPARTIMENT OF NATURAL RESOURCES 1972, administered by the OE-Fice of Area for Planning of Natural Coastal Zone Management, National Resources oceanic and Atmospheric Administration Coastal Management Program Property Of NOAA Coastal Services Center Library FLOOD HAZARD MITIGATION PLAN FOR PORTIONS OF THE COASTAL FLOODPLAIN OF RIO DE LA PLATA September 1980 In Response to September 1979 Disaster Declaration (FEMA 579 OR Puerto Rico) PROJECT STAFF Department of Natural Resources Fred V. Soltero Harrington, Secretarv Antonio Rodr1guez Figueroa, Under-Secretary Gabriel del Toro, Assistant Secretary for Planning Frank Molther, Special Assistant Rub@n Freyre, Consultant Fe'lix 1. Aponte, Natural Resources Specialist Mariano Vargas, Natural Resources Specialist ,juan Delgado, Natural Resources Technician Ada M. Sotto, Natural Resources Technician Ernesto Morales, Draftsman Marl'a Franco, Secretary Ralph M. Field and Associates, Consultant: Larry R. Johnston Stuart Braman Julie E. Troy CONTENTS Page 1. INTRODUCTION 1 11. DESCRIPTION OF THE AREA 5 A. RIO DE LA PLATA BASIN 5 B. STUDY AREA 5 111. DESCRIPTION AND EVALUATION OF THE FLOOD HAZARD 11 A. HURRICANE DAVID AND TROPICAL STORM FREDERIC 11 B. TYPICAL PATTERN OF FLOODING 14 C. FLOOD HISTORY 15 0. EVALUATION OF THE HAZARD 17 IV. FLOOD HAZARD MITIGATION POLICIES AND OBJECTIVES 20 A. FORMAL ISLANDWIDE OBJECT IVE S AND POLICIES 20 B. ADDITIONAL ISLANDWTZE POLICIES 21 V. IMPLEMENTATION MEASURES 22 A. SUMMARY OF RECOMMENDATIONS 22 B. TAARNING SYSTEMS 25 C. RESERVOIR RELEASES 27 D. EVACUATION PLAN 28 E. INFRASTRUCTURE 31 F. RELOCATION 32 G. STRUCTURAL MEASURES 35 APPENDIX A: FEDERAL/COMMONWEALTH DISASTER ASSISTANCE AGREF14ENT 44 APPENDIX S: HAZARD MITIGATION TASK FORCE 47 APPENDIX C: HAZARD MITIGARION WORK GROUP 48 APPENDIX D: SUMMARY OF RECOMMENDATIONS FROM PUERTO RICO, FLOOD HAZARD MITIGATION PLAN 49 LIST OF FIGURES Page FIGURE 1 RIO DE LA PLATA BASIN AND STUDY AREA 6 FIGURE 2 SUSCEPTIBLE FLOODABLE AREA MAP 8 FIGURE 3 FLOODS AT TOA ALTA, TOA BAJA 16 FIGURE 4 SHORT TERM MEASURES 37 FIG URE 5 PROFILES OF FLOODS 39 FIGURE 6 LONG TERM MEASURES 42 LIST OF TABLES TABLE 1 POPULATION ESTIMATES BY SECTOR IN TOA BAJA 9 TABLE 2 DISASTER ASSISTANCE REQUEST 13 TABLE 3 COST ESTIMATES FOR FLOOD CONTROL T40RKS 36 I. INTRODUCTION Between August 30th and September 6, 1979, Puerto Rico suffered extensive flood- ing from two violent storms -- Hurricane David and Tropical Storm Frederic. On September 2, 1979,President Carter declared six municipios disaster areas; eventually the disaster declaration covered 72 of Puerto Rico's 78 municipios. On September 7, 1979, Governor Carlos Romero Barcelo' signed a Federal/Common- wealth Disaster Assistance Agreement to allow Puerto Rico to receive federal disaster assistance funds. Paragraph nine of this agreement requires Puerto Rico to: ...evaluate the natural hazards in the areas in which the proceeds of the grants or loans are to be used..., take appropriate action to mitigate such hazards, including safe land use and construction prac- tices; and to follow up with applicants,. within Commonwealth capabili- ties, to assure that appropriate hazard mitigation actions are taken.2 Shortly before Hurricane David and Tropical Storm Frederic struck Puerto Rico, an Executive Order on disaster functions 3 assigned lead agency responsibility for hazard mitigation planning to the Department of Natural Resources (DNR). 1FMMA No. 597 DR Puerto Rico. See Appendix A. 2 The legal basis for this requirement is Section 406 of the Federal Disaster Relief Act of 1974 (P.L. 93-288), which requires as a condition of disaster assistance grants, or loans, that the state or local government agree that: 1) ...the natural hazards in the areas in which the oroceeds of the grants or loans are to be used shall be evaluated... 2) -appropriate actions shall be taken to mitigate such hazards, including safe land use and constructive practices, in accordance with standards prescribed or approved by the Administration of DR&R (FDAA) after adequate consultation with the appropriate elected officials of general purpose governments... ; and 3) ...the State shall furnish such evidence of comvliance with this section as may be required by regulations. Proposed regulations governing Section 406 were not issued until Abril 1979. Final recrulations were issued November 3, 1979 (44 CFR, Part 2C5, Subpart M, Hazard Mitigation.) 3Administrative Bulletin No. 3669: Governor's Executive order for Coordination of Executive Funcl:ion in Case of Disasters. August 22, 1979. - 2 - After the initial emergency operations related to the two storms were completed DNR, the Federal Emergency Management Agency (FEMA), Civil Defense Agency, and the Planning Board held a series of meetings to initiate hazard mitigation planning. These meetings clarified DWRIs role as lead agency and provided the initial direction for the hazard mitigation planning effort. As lead agency, DUR reassigned several staff members and consultants from other duties to prepare a work program for hazard mitigation planning. Recognizing that this type of effort would require interagency action, the work program called for establishment of a Hazard Mitigation Task.Force1 to include representatives from over 15 federal, Commonwealth and municipal agencies. A 2 smaller Hazard Mitigation work Group ,with members from three federal and three Commonwealth agencies plus several municipios, was also established. Based on the earlier discussion with otherkey agecies-, DNR proposed two types of hazard mitigation planning: a) the preparation of site-specific plans for selected target areas (potential areas were identified for review with the Task Force); and b) because flooding from David and Frederic was so widespread, the preparation of a general hazard mitigation plan for all of Puerto Rico (called the "islandwide plan"). At its first meeting on November 7, 1979, the Hazard Mitigation Task Force concurred with this overall approach, suggested a number of changes in the work program, and selected two initial target areas for site-specific plans coastal floodplains of Rio Grande de Lol'za and Rio de La Plata. A decision on additional target areas was deferred. At its second meeting on November 29th, 1See Appendix B. 2See Appendix C. 3 the Task Force approved a revised work program, which cqas subsequently approved by the FF1V% New York Regional Office. Following these approavals, DNR began to compile data and evaluate flood hazards for the two target areas and for the islandwide plan. Regular meetings of both the Work, Group and the Task Force were scheduled to periodically review this information and to recommend appro- priate hazard mitigation actions. This report -- Flood Hazard Mitigation Plan for Portions of the Coastal Flood- plain of Rio de La Plata -- presents the results of the investigation for the Rio de La Plata target areas.3 It briefly describes the flood hazard and Puerto Rico's policies for dealing with the hazard, describes on-going actions to reduce future flood losses, and recommends additional actions to be taken in the future. information included in the plan is derived primarily from the following sources: - National Weather Service. 'Hurricanes David and Frederic as they concerned Puerto Rico and the U.S. Virgin Island, March 1980. - Puerto Rico Department of Natural Resources, Coastal Flood Hazards and Responses in Puerto Rico: An Overview. February 1980. - Puerto Rico Department of Natural Resources. Hazard Mitigation Plan for Portions of the Coastal Floodplain of R@o Grande de Loiza. Ma- y 1980 (Draft). - Puerto Rico Department of Natural Resources. Puerto Rico Flood Hazard Mitigation Plan, August 1980. - Puerto Rico Water Resources Authority. La Plata Dam, 1974. - US Army Corps of Engineers. Flood Plain Information, La Plata River, 1965. 3 Hazard evaluations and mitigation recommendations that are specific to the Rio Grande de Lol'za target area are included in the Hazard Mitigation Plan for Portions of the Coastal Floodplain of Rio Grande de Lolza, September 1980. Evaluations and recommendations affecting the entire island are included in the Puerto Rico Flood Hazard Mitigation Plan, August 1980. 4 - Meetings of the Hazard Mitigation Task Force - meeting of the Hazard Mitigation Work Group - Staff work by DNR and other government agencies In addition to these major sources, numerous other documents prepared by several commonwealth and federal agencies were also used extensively. Several actions were taken by government agencies following David and Frederic, independent of the actions of DNR and the Task.Force. Because these actions are essential to the overall hazard mitigation effort, they are incorporated into the plan, to the extent possible. This Flood Hazard Mitigation Plan represents an intermediate stage in an ongoing hazard mitigaticnprocess. The Task Force and Work Group meetings along with ONR staff work represent the initial stage of this process. The process will continue beyond this report as steps are taken to implement the recommendations contained here. Those actions are the goal of this process. 5 11. DESCRIPTION OF THE AREA A. RIO DB LA PLATA BASIN Rio de La Plata begins at an elevation of about 900 meters above mean sea level in the Sierra de Cayey Mountains in the southeastern region of the Island. It flows generally northwest through the municipios of Cayey, Comerio, Naranjito, Toa Alta, Toa Baja'and Dorado for a total river distance of 102 kms., the longest in the Island. It enters the Atlantic Ocean at point 14 kms. west of San Juan, shortly after passing near the urban centers of Toa Baja and Dorado. Average annual rainfall over the basin varies from 130 inches at some portions of the headwaters to less than 60 inches at the coast. However, major floods in the Rio de La Plata floodplain are produced by high- intensity rainfall, which usually occurs in the upper lands and by insuffi- cient drainage on low lands. Three dams were constructed in the river at Ca-rite, Cayey and Comerio to produce hydroelectric power. Most recently, in 1975 the La Plata Dam was constructed upstream of Toa Alta as a water supply project. 3- STUDY AREA The Task Force determined that flood hazard mitigation planning would include those sections of the municipios of Tha Baja and Dorado that are located in the aJluvial 'Lloodplain at the lower northern end of Rio de La Plata. The area is located on the north coastal olain of Puerto Rico, to the west of the San Juan Metropolitan Area (See Figure 1). It extends CUENCA RIO LA PLATA 6 - 0 C A N 0 A r L A v r c o -,'OCR 400 A. CATAk L cc emao VFr ALI or WN a BAYAMON Rio Was TOA ALTA COROZAL Repraia La FIGIG HARANJITO CalSI4 Arn do amerio >4 RIO E-4 COMERIO z z BARRA UITAS CIORA jk@a E.4 a4 La PlatIl 4i 1;:4 if*AGOHIT0 Rio G@avall CAYEY 11111mm AREA ClEsruafo JAN 110AN Logo calt FAJAA CA4 UAS 0 1 2 3 4 5 .O.C! 0 1 2 3 4 5millas Tunii at ESCALA L 120,000 Rio G.amani -7 from the Sabana Seca area in the east, to various villages and hills in the municipality of Dorado in the west and from the Atlantic Ocean on the north to Toa Alta in the south. The Susceptible Floodable Area Maps (Mapas de Zonas Susceptibles a Inun- daciones) shown in figure 2 approved by the Planning Board delineate the floodplain. A recent Planning Board estimate based on this map established that the floodable area of the P-to de La Plata is 13,016 acres. The Floodplain is generally flat land intensively cultivated for sugarcane, pasture, minor crops, and dairy farms. A chain of hillocks running east- west delineate the floodplain in the south. The urban areas of Dorado and Toa Baja are located in the floodplain. Population in the lower basin of -RI'o de La Plata has increased rapidly in the last 20 years. Estimates prepared jointly by the Brureau of the Census and the Puerto Rico Planning Board in 1977 established the total population in 96,500 for both municipios; 74,400 in Tha Baja and 22,100 in Dorado. According to the census, the population of Toa: Baja increasIsed 135.5 percent between 1960 and 1970; in Dorado the increase was 29.2 percent during that petiod. A special census conducted in 19'78'in Toa Baja indicated that populatic had increased another 60.3 percent from 1970 to 1973. Planning Board projections estimated a 27.2 percent increase for Dorado from 1970 to 1977. (See Table 1 for population estimates by sectors in Toa Baja). .. . . ...... C A -C! 4.1,7LI4, 1C C-1 L 4@ @A I ;Ts 714 VAPAS OC ZONAS SUSCIFT14LES A INUNCACIONts wwo*-L- IN-OC-99 0 YEN"" at III" I a 4 5 0 1 32 altsim. FIGURE 2: Planning Board Susceptible Floodable Area Map for R@o La Plata Floodplain TABLE 1: Population Estimates by Sector in Toa Baja ESTIKAD09 Y PROYECCION DE POBLACION Y VIVIENDA POR COMUNIDAD TOA BAJA, 1970, 1995 Y 2000 1 9 7 9 1 9 8 5 2 0 0 0 PORLACION VIVIENDAS PORLACION VIVIENDAS POBLACION VIVIENDAS COMUNIDAD OCUP&D" VACANTES OCUPADAS VACANTES OCUPAVAS VACANTES Pueblo 2014 534 31 1095 531 34 1895 530 34 Tooville 300 06 9 565 113 10 565 163 10 Villa Calm 1562 389 40 17QO 419 27 1700 419 27 Ingenio 3136 -912 91 3622 990 63 3622 980 63 Sabana Sect 12841 3215 240 1.3508 3346 214 13500 3346 214 Levittown 31694 0198 929 42644 12184 720 50264 14361 917 Palo'seco 443 150 to 460 158 10 460 ISO 10 Campanillas 3010* 757 69 3633 776 so 0933 2399 154 Vill& Hostoo 2460 694 74 2557 722 46 2557 722 46 Candelarla 7151. 1771 124 7193 1759 112 7193 1759 132 MacGn 1651 431 29 1790 496 32 1798 496 112 Cl PIantf6 749 258 - 3104 1034 66 3104 1034 66 Covadongs 1400 403 36 2096 577 37 2090 577 37 PSjaro Norte 400 NO 0 1490 425 140 4526 1269 05 PAjaro Sur 5557 1290 66 14151 3704 203 15465 4160 225 San Joad 2008 450 46 2590 599 39 2590 599 38 Nuevo Centro -- -- -- -- -- -- 23030 fiseo 420 Total 76935 19721 1036 103000 27961 1072 143200 39560 2490 Fuentes I. U.S. Departamento de Comerclo, Oficinst del Canso, Canso Especial, To.a Baja, 1970. 2. Proyocclonew do Pang V. Batista y Asoclados on bags a to Proyaccift do Uno do Terrence B 10 According to the Planning Board Report, Housing Situation in Puerto Rico, 1978, there was 18,637 families in Toa Baja in 1977. The 20.74% (5,357) families-vas below the poverty level as established by the F6od and Agricultural Act of 1977. The 14.79% (2,757) of total housing number is considered inadequate. In Dorado there was 6,275 families in 1977. The 38.10% (2,391) of total number of families was-below the poverty level. The 25.24% (1,584) of total housing number is considered inadequate. --11 - III. DESCRIPTION AND EVALUATION OF T14E FLOOD HAZARD A. HURRICANE DAVID AND TROPICAL STORM FREDERIC The flooding that triggered this hazard mitigation p-lanning effort hit the Plo de La Plata f loodplain along with the rest of Puerto Rico during late August and early September 1979. During the night of August 29- 30, Hurricane David passed 100 miles south of Puerto Rico causing heavy rainfall.- Flood waters began to rise in some areas by Thursday evening, August, 30th. Flooding also ocurred over the east, south, and north sections of Puerto Rico during early morning and during the day of August 31tt. During its passage southof Puerto Rico, Hurricane David delivered some of its hea-4est rainfall to the RIO de La Plata basin (on the order of 20 inches). The most severe flooding in the basin ocurred in the coastal plain area surrounding the towns of Toa Baja and Dorado. By the evening of August 30th much of the town of Toa Baja was under water and in the low lying barrrios floodwaters reached depths of 10 feet. Ah, it 500 people from Barrio Ingenic@cne ofthe worst hit area, took refuge in public shelters, and over 1,100 people were evacuated from San Pedro Urbanization. Most of these people lost all or part of their belongings and suffered serious damages, or.in some cases complete loss, of their homes. The river left its banks just below Toa Alta, which is somewhat higher than Toa Baja, and flooded several hundred acres of sugar cane fields surrounding the towns of Toa Baja and Dorado. The main bridge entering Dorado was overtopped and the lower sector of the town Of the south had three to four feet of water. A few days later, on September 4th, Tropical Storm Frederic entered eastern Puerto Rico, just north of Fajardo, at about 8:00 A.M. The storm continued westward across the island during the day and leftjust north @tw of Mayag"uIez in mid-afternoon. Serious flooding again occurred. Following David and Frederic, the municipalities of Toa Baja and Dorado were declared Presidential disasters areas, making them elegible for individual and public assistance. Damages to infrastructure were extensive mostly to the telephone systems, roads and drainage channels. @The total disaster assistance-requests in both towns were 1.43 million dollars. The most affected municipality was Toa Baja with 1.36 million dollars in damages. A summary of disaster assistance requests for in- frastructure is shown in Table 2. Damages to homes and business in thelower Rio de La Plata floodplain cannot be accurately documented because most records of requests for assistance and aid provided are aggregated -or all Puerto Rico. However,, estimates from Toa Baja and Dorado local Civil Defense uffices established that 2,000 persons were evacuated and 10,000 homes affected in Toa Baja; 720 persons were evacuated and 1,000 homes affected in Dorado. Although the flooding due to David and Frederic in this area was extensive, the recurrence interval was estimated to be on the order of one in 6 years according to data gathered by the Flood Hazard office of the Deparment of Natural Resources;the potential for property damage'and loss of lives is higher if flooding of a greater recurrence interval hits the area in the future. The following section's provide some perspective on the extent and magnitude of flooding and damages caused by David and Frederic. DISASTER ASSISTANCE REQUEST (DAMAGE SURVEY REPORTS) FOR SEPTEMBER 1979 DISASTER DECLARATION (DOLLARS) DORADO TOA BAJA NO. OF DSR'S TOTAL A. DFXRIS CLEARANCE Public Roads Systems B. PROTECTIVE MEASURES Stream Drainage_Chanhels 414U5.00 20,653.00 7 25,058.00 C. ROAD SYSTEMS Roads 33,417.00 102,521.00 35 135,938.00 Bridges Streets Retaining Wall Culverts D. WATER CONTROL FACILITIES Drainage Channels E. PUBLIC BUILDINGS, EQUIPMENT Vehicle, other r. PUBLIC UTILITY SYSTEMS Water Sanitary Sewerage 19,833.38 3,104.80 9 220930.18 Storm Sewer Storm Drainage 1501036.00 5 150,036.00 Light Power Telephone 10,686.28 1,086,942.40 22 1,097f628.68 G. FACILITIES UNDER CONSTRUCT. Public Facilities If. PRIVATE NON-PROFIT Yacht Club I. OTIIER Park Facilities (Walkway) Recreational Facilities (Fence) TOTAL 68,341.66 1,363,257.20 is TABLE 2 DAMAGE SURVEY REPORTS b 4 B. TYPICAL PATTERN OF FLOODING During periods of normal rainfall the natural drainage is adequate, but during heavy rain, flooding begins quickly in the lower portions of the floodplain. Two factors delay the discharge of floodwaters and increase flood levels. First, sand dunes about five meters high run along the north coast of the floodplain providing only two small outlets to the sea: one at the mouth of Rio de La Plata (Punta Boca Juana) in the west and the other in Rlo Cocal (Punta Corozo) in the east. Highway #1651 running across the top of the sand dunes, reinforces this natural barrier. Second, the increase in tide elevation during storms creates an additional barrier; floodwaters cannot flow rapidly into the sea, thus creating backwater along the floodpalin. A system of channels in the floodplain provide drainage to Rio Cocal and Cafic, Camp4nero. Rl'o Cocal, in the north of the floodpain, is connected in the west with the Rio de La Plata and in the northeast with the sea. The drainage channels vary in length, width and depth, but practically all have only a gentle slope because of the small elevation of the floodplain. Their hydraulic capacity is further reduced because of lack of channel maintenance. As a result of these factors, floodwaters spread over the flood- plain during heavy rains. The town of Toa Baja, near Rio de La Plata, is periodically flooded to depths of 0.6 to 1.2 meters. Floods with an estimated recurrence frecuency of 1 in 10 years have a dramatic impact on the area, affecting 12 to 15 thousands persons. -15 C. FLOOD -HISTORY Mayor flooding of Rio de La Plata is usually associated with the passage of a hurricane near or over the island. The floodplain, a 37 squaremile area below Toa Alta, had been affected by recurring major floods. See Figure (3) Floods at Toa Alta, Toa Baja and Dorado Puerto Rico. The flood of August 8, 1899 is the greatest known flood and was associated with San Cir'iaco, one of the most destructive' hurricane in the history of Puerto Rico. The estimated peak flow on Rio de La Plata was 140,000 cfs., with an estimated frequency of ocurrence of one in 100 years. Damage were estimated at $585,000 in'the Rio de La Plata Basin: more than 3,000 lives were lost throughout Puerto Rico - Rains in the central region around Cayey associated with the passage of Hurricane San Hip6lito on August 22, 1916, produced major flooding with a recurrence interval estimated at one in 35 years. Damages in the La Plata Basin were calculated at $260,000 On Septembre 13, 1928 the passage of Hurricane San Felipe 11 caused extensive damages to agriculture, commerce, hydroelectric plantsi and villages. As in previous major floods, the entire town of Toa Baja was flooded . Depth of flooding was about 0.9 meters in the streets and between 0.1 and 0.6 meters in buildings. The town was covered by water for about nine hours. Floodwaters rose to a height of 0.3 meter next to the rail- road bridge near Dorado and the bridge on Highway #2. in the floodplain, about 2,500 acres of sugarcane were flooded to a maximum depth of 0.4 meter; dairy farms also suffered damages. The floodwaters had a discharge of 120,000 c.f.s. and an estimated frequency of ocurrence of one in 60 years. 16 ALM 6"ovew rem.& A rt- Asv ri c 0 C CAN ell a FA W-V-f-A rw -A.'* &AMA 3 Z C A .44, It- V; gig- V') -%LOOM& amomm. C A 1,A ,@7 Vl I @AS MWMAW OP 00WOMW *P MHM4RAM0- *am Mm W's" cownun iwrgwv" Is 0 "Tw 0 W" MA FIGURE 3:lruwos AT TOA ALTA,TCA BAJA ANO DORADO FNJVM RICO. - 17 Damages were calculated in $409,700 in the La Plata basin. Numerous floods occurred between 1928 and 1960, most of them local in character or of lesser magnitude than San Felipe II. on September 5 and 6, 1960 torrential rains occurred associated with Hurricane Donna, which passed 150 kms. north of Puerto Rico. A record 14.07 inches in 24 hours was'recorded at Cayey. The flood had an estimated frequency of occuxrence of one in 35 years. Damage in the floodplain were estimated in $172,000. Serious flooding also occurred in August 1961, October 1970 and September 1975. Recently, Hurri:cane David and Tropical Storm Frederick make extensive damages to the floodplain. The total disaster assistance requests in both municipios were 1.43 million dollars- D. EVALUATION OF THE HAZARD The Metrocolitan San Juan Area is rapidly expanding into areas adjoining the La Plata floodplain. Many small villages have been established in the floodp@ain itself in recent years, rapidly increasing the population in the area. There has been an increase in demand for both industrial and residential sites in the area. This present and potential future develop- ment will increase the potential for flood damage in the area. Some preliminary studies had been developed to deal with the flood problem in the area. However, at present, no general scheme of protection for the floodplain has been implemented. The t@orps of Engineers, in its report Flood Plain information, La Plata River June 1965, established guidelines for reducing flood damages in the area. According to the report, the flood hazard for Rio de La Plata floodplain is severe, and preliminary investigations indicated that direct flood control measures would reduces flood stages and provide protection to life and property. A combination of works appeared to be the best solution to the flood problem. The general plan that was developed included channels, levees, floodwalls and various possible dams and reservoirs sites in Rio de La Plata and in its tributaries (when this report was published La Plata Dam, at Toa Alta, had not been constructed). in addition to these structural measures, the developmeat or improvement of other non-structural measures would be required to deal adquately with the flood hazard in the area. Development of flood fighting and emergency evacuation plans, improvement of flood forecasting and warning services, revision and/or enforcement of the floodplain regulations were suggested. Despite the severe flood problem of Rio de La Plata, the Federal Government has not been able to allocate funds to assist with structural protects for flood control: annual monetary damages from flooding have not been great enough to justify the needed structural improvements. However, the low economic losses have not reflected the severe social impacts of destructive floods, principally the human suffering. Because family incomes and housing values are low, a home destroyed by flooding may represent only a few thousand dollars in economic loss, but to the family affected it could be a life's accumulated wealth. On the other hand, land and cons- truction costs for providing structural solutions are high. As a result, annual benefits are low and costs are high. Consequently, it has been 19 impossible to justify Federal in@olvement in structural projects to reduce existing levels of damages. Th 1975 the Corps of Engineers began a Preliminary Survey Report for Rio de La Plata. The Corps of Engineers identified two str uctural intensive plans for flood protection of the lower Rio de La Plata floodplain to include the town of Toa Alta and the areas-downstream. Plan A - includes a dam and reservoir above Comerlo, a floodway-type channel in the lower reaches, and a standard-type channel near Toa Alta. Plan B - does not include the reservoir but includes the channels described above@ These pr eliminary plans assumed extensive urbanization of the Rio de La Plata floodplain in the future. Using this assumption of extensive urbanization, a cost benefit analysis indicates the long term feasibility of the project. Howerver, the Planning Board has classified the floodplain as a high agricultural productivity area, an alternative analysis must be develop if the flood plain is reserved for agricultural use. Until today this kind of analysis has not been studied. The major investment required for development of large structural projects make their construction unlikely in the near future. Therefore, this hazard mitigation plan focus on minor structural and nonstructural measures as the most feasible means of reducing flood hazards. - 20 IV. FLOOD HAZARD MITIGATION POLICIES AND OBJECTIVES A. FORMAL ISLANDWIDE OBJECTIVES AND POLICIES Primary responsibility for the development and implementation of public policies and actions to guide development throughout Puerto Rico, in- cluding flood hazard areas, rests with the Puerto Rico Planning Board. official Planning Board policies on development in flood hazard areas are contained in the Objectives and Public Policies for Land Use, adopted by the Board in June 1977. These were also incorporated into the Puerto Rico Coastal Management Program by the Department of Natural Resources in July 1978. The principal objectives and public policies relating to flooding are quoted below: 1 OBJECTIVE To reduce to a minimum the danger of loss of life and physical damage in the country, as a result of flooding and the action of wave surge -- at the same time identify and promote those land uses and activities compatible with these conditions. PUBLIC POLICIES 10.00 To protect the population actually residing in flood- able areas or in areas affected by the action of wave surge. 10.01 To construct engineering works which will, at a reasonable cost, prevent property damage and risks to the lives of the citizenry actually affected, giving priority to these works above any other flood control measures. 10. 02 Where necessary, to take the appropriate measures to relocate these persons. 11.00 To prohibit land development and construction of struc- tures for urban expansion and other activities which are expressly excluded by current regulation in areas affected by floods and wave surge, except when flood control works or protection against wave surge already exist, are under construction or can be provided at a reasonable cost, to protect the property and guarantee the safety of all the people affected in those lands which are not agricultural(ly) productive, do not have important natural resources, and are not environmentally critical. official English translation. 21 12.00 To stimulate agricultural development in floodable areas which have such potential. .13.00 To construct flood control works with an agricul- tural approach in areas where it is appropriate, and which will result in an increase in agricul- tural production. B. ADDITIONU ISLPMWIDE POLICIES The official Planning Board policies are the most formal and broadest statement of the Commonwealth's position -- but not the only expression of public policy -- regarding development in flood hazard areas. Regu- lations, programs, and activities of the Planning Board and of other agen'cies are a less formal, but still integral, part of the total Com- monwealth policy regarding development in flood hazard areas. The Hazard Mitigation Task Force found it desirable to formally state several of these informal policies: 1. To continually add to and impro@re data on the frequency, extent, and magnitude of flood hazards and their effects. 2. To develop flood hazard -initigation plans for high risk areas. 3. To increase the level of public awareness of flood hazards and what actions they can take to prevent or reduce risks to their person and property. 4. To encourage the purchase of flood insurance by those who live in floodable areas. 22 V. IMPLEMENTATION MEASURES The following sections describe the measures discussed and recommended by the Hazard Mitigation Task Force to reduce future flood losses in the lower Rio de La Plata Floodplain. S1 A. SM4MARY OF RECOMMENDATION Following is a summary of the recommendations that apply specifically to the lower Rio de La Plata floodplain. Subsequent sections provide a discussion of the considerations leading to the recommendations. WARNING SYSTEMS 1- A fully automated flash flood warning system for the lower-Rio de La Plata floodplain should-be developed and implemented. The warning system should consist of a radio network of event reporting rain gauges, repeater stations, river gauges, a microprocesor or minicomputer and radio flash flood alarms. 2. The Puerto Rico Civil Defense Agency should study the need for additional sixens,.alternative locations for such sirens, and the cost of new sirens for the flooding areas in both municipalities. 3. Local civil defense offices in Dorado and Toa Baja should purchase NOAA band radio recervers so that weather warnings can reach the public faster. This receiver is relatively inexpensive. 4. A written agreement should be entered into between P.R. Civil Defense and the National Weather S-@,rvice to provide for improved information exchange. The Puerto Rico Hazard Mitiaation-Plan contains a number of recommendations that, when implemented, will apply throut Puerto Rico, including the lower R@o de La Plata Floodplain. These islanwide recommendations are presented in Appendix D. 23 RESERVOIR RELEASES 1. Upon installation of gates on the La Plata Dam, PRASA should conduct a study to evaluate the impact of dam operation on downstream flooding. This study should adress: a. Establishment of management measures for the dam that take into account the flood hazards downstream from the dam, including: - Written management measures available to the State and local civil deffense offices. - An estimate of the time it takes for water released at the gates-to arrive at the floodplain. b. Establishment of warning systems in the municipios of Dorado and Toa Baja. - warning sirens in strategic points - An effective comunication within PRASA (dam operators), NWS and State and local civil defense offices including precipitation in the drainage area, water level in the dam, information on water release from the dam, etc. 24 EVACUATION PLAN Due to the inadequacy of existing emergency evacuation plan in the area, the Task Force recommended that the U.S. Army Corps of Engineers prepare an emergency evacuation plan. The Corps of Engineers responded to the request and initiated work on the plan. 1. The study will require coordination with various local and federal agencies in the gathering of information. The Task Force encourage the cooperation of such agencies. The P.R. Civil Defense Agency will be the principal coordinator of the study for the Commonwealth. The Civil Defense Agency should encourage public involvement so that residents understand the reason for the plan and the role they must play in its proper execution. INFRASTRUCTURE 1. Request the Puerto Rico Highway Authority to revaluate the design of the proposed bridge over De Diego Expressway at Toa Baja. This reevaluation should address two major concerns of the Task Force: � The proposed design of the bridge apparently does not provide for probable future stream realignment and/or-channelization projects. � The proposed design apparently did not fully take into account the historical pattern of flooding in the area. The length of the bridge is not sufficient to permit the free flowing of flood waters according to the maximum historical flood in the area. 25 RELOCATION -Relocation should not be pursued in Dorado and Toa Baja. There would be substantial negative social impacts associated with relocation of these long - established communities, and other protective measures appear to be more cost effective. STRUCTURAL MEASURES This plan focuses on minor structural measures and nonstructural me measures as the most feasibles means of reducing flood hazards. The Task Force endorse the short - t4rt measures presented in this plan because of the imperative need to take some protective measures. However, the major investment required for development of large structural projects make their construction unlikely in the near future. B. WARNING SYSTEMS Flash Flood Warnings For Dorado and Toa Baja, as well as for the rest of the island, the National Weather Service (NWS) is responsible for issuing weather reports and forecasts. Twice a day, the NWS receives information from a net work of rain gauges across the island, and issues forecasts and flood warnings through teletype and NOAA Radio (162.4 MHz - VHF). A new weather radar was installed in late summer of 1980 at Isla Verde Airport to improve weather forecasting, and the NWS is moving toward full automation to attain more accurate forecasting. 26 Once forecasts are prepared, they must be transmitted efficiently to local goverments and the public to be of any use. At present there is issuficient direct information exchange between the Puerto Rico Civil Defense Agency and the National Weather Service. Cormunications most often go from NOAA Radio to the State Civil Defense then to the Regional Civil Defense offices, then to the local civil defense and finally to the public. In Dorado and Toa Baja, local civil defense personnel use popular broad- casting (radio, T.V.), radio communications, and telephone to transmit warnings. in addition, citizen's band radio has been found to be very heplfull during emergencies. When flood warnings are issued to the local office, the civil defense employees are alerted and volunteers are activated. Local police and firemen are contacted and the possible flood situation discussed. The civil defense employees had established their own water level marks in some strategic points. Such marks indicate them when they has to alert and evacuated different sectors of the municipality. The emergency warning are given with sirens and loudspeaker systems. Recomendations 1. A fully automated flash flood warning system for the lower Rio de La Plata floodplain should be developed and implemented. The warning system should consist of a radio network of event reporting rain gauges, repeater stations, river gauges, a microprocesor or minicomputer Located in the central office of the National Weather Service in San Juan and radio flash flood alarms. This recommendation was made by the National weather service in its evaluation report after hurricans David and 27 Frederic and has-the endorsement of the Task Force. 2. The Puerto Rico Civil Defense Agency should study the need for additional sirens, alternative locations for such sirens, and the costs of new sirens for the flooding areas in both municipalities. 3. Local civil defense offices in Dorado and Toa Baja should purchase NOAA band radio receivers so that weather warnings can reach the public faster. This receives is relatively inexpensive. 4. A written agreement should be entered into between Puerto Rico Civil Defense and the National Weather Service to provide for improved in- formation exchange. C. RESERVOIR RELEASES La Plata Dam is a concrete gravity structure located about 7 miles upstream from the town of Toa Baja. The dam was completed in 1974 to create a water supply reservoir that is part of the San Juan Metropolitan Water District, it presently provides a safe yield of 64 million gallons per day, and. was designed for future modification,to provide more water when demand so requires. The reservoir is maintained at spillway cre-ist elevation as much as possible, providing 22,700 acre - feet of storage. Hydrologic studies maked by consultants of PRASA have shown that the presently ungated dam spillway can not reduce flood hazards in the coastal floodplain downstream. The Puerto Rico Aqueduct and Sewer Authority (PRASA) is currently preparing for an additional $16.3 million of construction on the La Plata Dam to increase water supply reserves for the Metropolitan Area, Six bascule gates will be constructed over the spillway that will increase the storage from 22,700 acre-feet to 33,150 acre-feet and crest elevation Erom 47.12 to 52 meters. Although the design does not provide for flood control storage above the water supply pool elevation, PRIASA feels that the additional storage and 28 - gates can help to mitigate downstream flooding problems. RECOMMENDATION 1. Upon instalation of gates on the La Plata Dam, PRASA should conduct a study to evaluate the impact of dam operation on downstream flooding. This study should adiress a. Establishment of management measures or procedures for the operation of the dam that take 'into account the flood hazards downstream from the dam, including: � Written management measures or procedures available to the State and Local Civil Defense offices. � An estimate of the time it takes for water released at the gates to arrive at the floodplain- b. Establishment of warning systems in the municipios of Toa Baja and Dorado. warning sirens in strategic points An effective communication within PRASA (dam operators), NWS, and State and Local Civil Defense Offices, including information on precipitation in the drainage area, water level in the dam, infornation on water release form the dam, etc. D. EVACUATION PLAN The Puerto Rico Civil Defense Agency is designated by Law Number 22 of June 1976 as the agency responsible for coordinating the activities of all Co=onwealth and municipal agencies in response to emergencies and disasters, including evacuation from flood-prone areas. Responsibility for actually evacuating people in time of flooding is shared by the Puerto Rico Civil Defense Agency and municipal Civil Defense organization- Each municipal civil I defense organization is required to have an emergency operation Plan which should include temporary evacuation procedures. -29 - None of the municipalities currently has an adequate formal evacuation plan specifying evacuation routes., procedures, and so on. The evacuation proce- dures are based on the experience of previous flooding conditions. Both municipalities, Dorado and Toa Baja, has limitations in personnel and funds. The restricted number of regular local civil defense employees and lack of basic equipment such as uniform, boots, vehicles, boats, etc. Fortunately, the volunteer groups gives an important support to the local civil defense personnel. The utilization of CB. receivers by some of these volunteers has proved to play an important role as well as private owner boats. Because of the known widespread flooding areas the Red Cross and the National Guard personnel are movilized rapidly to the area. The public schools and community centers are used to shelter refugees. These refugees need to be properly supplied with beds, medical equipment, beds clothes, food, medicines, etc- .More than 3,000 persons were refugees in Toa Baja and more than 1,000 in Dorado according to local civil defense estimate. nurinc,T David and Frederic near 10,000 houses were affected in -.0a Baja and 1,000 in Dorado. The principal evacuation routes utilized were roads PR-165 and PR-865 both -eastward in Toa Baja and PR-693 westward in Dorado. Refugees were reovilized principarly to schools or public,coTmunity centers. 30 Due to the inadequacy of existing emergency evacuation plans in the area during the early stages of this flood hazard mitigation planning effort,. the Task Force recommended that U.S. Army Corps of Engineers prepare an emergency evacuation plan for this area. This Task Force recommendation was followed by formal requests to the Corps of Engineers from the Depart- ment of Natural Resources, Puerto Rico Civil Defense Agency and the municipios of Toa Baja and Dorado for assistance in preparing an emergency evacuation plan. The Corps of Engineers responded to the request and initiated work on the plan. A plan of Study issued in July 1980, lists several* questions and problems to be addressedt a. Assess the adequacy of the Ric de La Plata existing flood warning system. b. Assess the adequacy of the various Commonweklth and municipio preparedness plans for evacuation in the Rio de La Plata area. c. Determine the critical areas to be evacuated. d. Determine the evacuat-"jn zones. e. Determine the evacuation routes. f. Determine the shelters to be used for evacuation. g. Determine the Structural adequacy of the primary sherlters. h. Determine the time needed for evacuation and recommended times for issuance of evacuation orders. .i. Distribution of the R'lo de La Plata Flood Emergency Evacuation Plan for public information. The emergency evacuation plan is scheduled to be completed in June 1981. RECOMMENDATION The study will require coordination with various local and federal agencies in the gathering of information. The Task Force encourage the cooperation of such agencies. The Puerto Rico Civil Defense Agency will be the principal coordinator of the study for the Commonwealth. The Civil Defense Agency should encourage public involvement so that residents understand the reason for the plan and the role they must play in its proper execution- E. INFRASTRUCTURE Heavy rains and associated flooding have caused extensive damages to floodplain infrastructure in the past. Further damage will occur in the future. Proper measures must be taken now if more serious damages to infrastructure is to be avoided in the years ahead. Special attention must be given to future structural development, particularly that which has potential to change the floodplain characteristics. The proposed bridge over R'lo de La Plata on the Diego Expressway PR-22 at Toa Baja, represents the greatest potential for modifying the present floodplain characteristics,. Construction of the bridge as presently designed would increase the potential for flood damages especially those areas south upstream of the proposed construction. RECOMMENDATION The Task Force after careful consideration agreed to request the Puerto Rico Highway Authority to reevaluate the design of the proposed bridge over De Diego Expressway at Toa Baja. This -reevaluation should address t%,-0 major conscerns of the Task Forc6: 0 the proposed design of the bridge apparently does not provide for probable future stream realignment and/or channelization projects * the proposed design did not fully takeiia to account the historical patterns of flooding in the area. The length of the bridge is hot sufficient to permit the free flowing of flood waters according to the maximum historical flood in the area. F. RELOCATION Since*Rlo de La Plata floodplain is-ofte 6f the largest area near the Metropolitan Area suitable for building they have been extensively developed in recent years and thousands of people live and work in the floodplain Many@of-these people live in high risk areas that area subject to frecuent and severe flooding. The analysis of this situation have focus around the possibility or desira- bility to permanently relocate all of these people from the floodplai=. The Department of Housing has recognized that there are many floodplain residents that could be permanently relocated- They also recognized t-he potential social and economic impacts of undertaking such a program. in addition they have recognized the need for a socioeconomic study of t:Me flo odable areas, prior to relocation. This a ctivity will provide for a proper selection of the most critical areas and the analysis of the feasiLility, relocation cost, identification of alternate locations and source of f=ds. J The Department of Housing has developed an analysis of the cost of acquisition and relocation of buildings located in floodable areas of Dorado and Toa Baja Key Figures from this analysis are presented below. Areas under study Municipality/Sector Estimated No. of Structures Dorado: Villa Caito 23 Villa ?lata 364 El Cafio 35 Villa Santa 51 Sub-total 473 Toa Baja: Villa Calma 361 Villa Pelusa & Hcstos 430 Sub-total 791 Total 1264 34 Total cost for the relocation of all these communities is estimated at $46 million, of which $14 million would be utilized for acquisition and $31.6 million for relocation. Ren6 Batista and Associates, as consultants of Toa Baja municipality, estimates the cost of relocation of Toaville, Villa Calma, sectors of Villa Hostos and Candelaria at $60.1 million. This estimate includes the relocation of 1,954 structures and was calculated based on cost estimates utilized by the Housing Department. Recommendation: Relocation should not'be pursued in Dorado and Toa Baja. There would be substantial negative social impacts associated with relocation of these long-esta.blished coumunities, and other protective measures appear to be more cost effective. 35 STRUCTURAL MEASURES Various studies for flood control had been developed for the Rio de La Plata floodplaia. In 1975 the Corps of Engineers developed a preliminary cost- benefit analvsis. of the channelization of Rio de La Plata assuming future extensive urban development of the area. Reng Batista and Associates, consultants to Toa Baja Municipality, has been preparing a plan for flood control measures. They have recommended various measures, both short - and long - term to mitigate the severe impacts of flooding in the Rio de La Plata floodplain. A brief description and Key points of these studies follow. Short-Term Measures The short-term measures for flood control are intended to 3:)rotect againts floods with a relative low frecuency of recurrence- Measures recommended by Batista and Associates are expected to protect against floods with a recurrence interval of one in 10 years@ These short-term measures have a preliminary estimated cost of 14.9 million dollars. These measures were presented and discussed both at Work Group and Task Force meetings. The Hazard Mitigation Task Force endorsed the -short-term measures f'or flood control- Table 3 and Figure 4 details the short-term measures proposed for the Rio de La Plata floodplain by Batista and Associates. The munic.14pality of Toa Baja expressed his disposition for use Housing and Urban Develooment (RUD) funds to share the cost for the development of these measures if other agencies, local or federal, assign funds to complement the total cost. TABLE 3 O)ST FLOOD C011,111(ifl. SHORT-TI..'IM PLAN 1110 DF, LA PINVA PIMA AND DOMDO ACT tv ur t i,:i; (Mrvri,ry UNIT CoST 1. Realicriment of Rio do La Plata from lliahwdy PR-2 Uo the inOULh 700,000 rneterO G. 00 11 , 200,000 '2 Const-rucII-Jon of a fotd aL the entrajice of Dorado rown 100,000 meters 3 6.00 600,000 J. Fnlarqenu@nt and clu-aning of Rio de La Plata im-itith 30,000 IIIL'L-(--rS3 1 lio, Ooo 4 . Close the flow ent-rance froin Rio de La Plata to HTo Cocal 100 yardS3 300.00 3o, 0()0 '0 S. To rise the level of RR-867 in a ford bridge way 1 200 mts./L '150.00 900,000 6. Improvement of Ca6o Campanero 3.- and other local channels 450,000 meters 6.00 '7. protectioli leve(-:!s at Toa Baja Town, Toaville, Villa Calma, Villa 3 flostos and San Jos6 196,000 meters 10.00 1 mm H. Water pump sysLems at Toaville, Villa Calma, Toa Jiaja Town y Villa flostos 4 c/u 400,000.00 1,600,000 ,j. cleall-ij"19 or s.i.nkhotus at Candelaria and Mic,61, 13 C/U 30,000.00 240,000 3 '120, OUO muters 6. 00 10. fruptovemenL of 1?1.() COcill Streal" TOTAL 14,930,000 A A TL A m ir i C 0 C E A N A A E US E NA DA OF ROCA V F IFJA 1APA"A IV IA.14 IV fV' t.V14A 1!0 Flo + U got - Alp 40 FinaAnwxy R1 bIK 7 A ALTA L F L 140: FTH At% UtL K M FLOOD HAZARD MITIGATION MEASVR GOURCK: PINI NATIBU,A920C, P10 VE LA PLATA FLOODPLAIN- . .......... . .... FIGURE'.4 Short Term Measures 38 The Flood Hazard office of the Department of Natural Resources developed a profile of flood discharges in Rl'o de La Plata during David and Frederic (See Figure 5). DNR staff also determined that these floods on the Rio de La Plata floodplain had an estimated frecuency of recurrence of one in six years. Despite this low return frecuency, damages were extensive along the floodplain. Therefore, it can be expected that the short-term measure proposed can help extensively to mitigate flood hazards in the areas of Toa Baja and Dorado. The following protection measures were recommended by the local Government of Dorado in the disaster report after David and Frederic in September 1979 and has the endorsement of the Task Force. 1. Cleaning,'conservation, alignment and stream wall of 1.5 kms. of channel south of the town for protection of Korea and San Antonio Communities ................. ........................ $50,000.00 2. Cleaning and conservation of drainage channel of 0.8 kms- south- east of Villa Plata and Villa Terrones Co=-.unities ........ 12,000.00 3. Reconstruction of storm sewer in the Urb. Costa de Oro to protect 30 homes ............ ........... ..................... 8,000.00 4. Cleaning and conservation of channel in Villa Santa Sector 10,000_00 S. Construction of storm sewer and reconstruction of street to protect El Coto Community in Barrio Maguayo ........... ..... 80,000.00 $160,000.00 A --- - -------- Z M 4 U19TAPICF FROM MOI)TI1,M KILOMETEng OF @1-00DS ON RIO LA PLATA FIGURES 5 40 Long-Term Measures The long-term solution for La Plata floodplain is the channelization of Rio de La Plata to give protection from a 100-year flood. In 1975 the Corps of Engineers prepared a preliminary analysis of alterna- tive plans and economic analysis. They recommended two basic plans. Plan A Include a flood control reservoir above Comerio, a floodway-type channel in the lower river reaches and a standard-type channel near Toa Alta Plan B Include the channels described above but eliminate the reservoir. Cost estimates (1975) for these plans are: Plan A - Reservoir with Channel Amount Total Investment ------------------------------- $ 106,800,000 Total Annual Cost $ 6,600,000 Plan B Channel Onlv Total Investment ------------------------------- $ 87,100,000 Total Annual Cost ------------------------------- 4,200,000 Flood control benefits assuming future urbanization of agricultural areas was also computed for Plan B. The results of the analysis are: Annual flood reduction benefits $ 1,500,000 Annuallocation and intensification benefits 4,300,000 Total Annual Benefits $ 5,800,000 41 Ren6 Batista and Associates, recently (1980) estimated the costs for channelization of Rl'o de La Plata at $132 million. The large cost of chan nelization contrasted with the lower value of damages,at present indicates a low probability for federarl financial assistance for channeli- zation in the near future. Justification for channelization works, however, will depend on future development plans for the floodplain- (.See Figure 6) RECOMMENDATION This plan focuses on minor structural measures and nonstructural -measures as the most feasibles means of reiucing flood hazards. The Task Force endorse the short-term measures presented in this plan because of the imperative need to take some protective measures. However, the major investment required for development of large structural projects make their construction unlikely 11 the near future. -'N A I LAM TIC U C E A M (NSfMAJ-l .,f BOCA VIEJA Pin @7' 9-0- 1C A IL 0 a 4 WKDIA LUN A kt ViltA c.pAmiLLA A li,A Aq 4AXDKt.AALAj_A AJA U 64@ f t". TOA ALTA Lf P40: EICHAk,tL ORM FLOOD HAZARD MITIGATION MEASUR Sovoct: 09"1 DATIOTA.ABSOC, J?10 VE LA PLATA FLOOI)PLAIN: FIGURE .6 Lonq Term Measure - 43 - I APPENDICES 44 APPENDIX A: FED 0,@111(),NAVEALT11 I)ISASTER ASSISTANCE AGREE,%IENT %'E@A'L EMERGENCY MANAGEMENT AGENCY RECIONAL OFFICE 26 FEDERAL PLAZA. NEW YORK. NEW YORK 10007 REGION 11 September 5, 1979 Honorable Carlos Rome'ro-Barce16 Governor of the Co=onwealth of Puerto Rico San Juan, Puerto Rico 00903 1 Dear Governor Romero-Barcel6: 1. This letter is the Federal/Commonwealth Disaster Assis- tance Asreement for a Major Disaster, No. FEMA 597 DR Puerto Rico, under Public Law 93-288, in accordance with Section 2205.44 of the Federal Disaster Assistance Re ulations. A COPY Of the Re lation3 znd Exhibit A, Federal Financial Assistance, anFExhibit B, Commonwealth Certification C-fi- cers, are attached hereto and made a part hereof. 2. On September 2, 1979, the Presidunt determined that da- mages resulting from high winds, heavy rains, and flooding beginning on or about August 29, 1979, have caused a major disaster* in the Commonwealth of Puerto Rico and you hereby acknowledge receipt of notice of this declaration. You have certified that the Co=onwealth of Puerto Rico or other pu- blic agencies thereof are expected to elpend $5,000,000, for disaster relief purposes for which no Federal reimbursement has been or will be received, in accordance with the table contained in your request, as amended. A copy of your re- quest is attached hereto as Exhibit C,and made a part hereof. 3. Federal assistance will be made available in accordance with Public Law 93-288, Executive Order 11795, and the Re- gulations attached hereto. 4. The duration of the catastrophe, causing the damage with vhich this Agreement is concerned, is from August 29, 1979, through September 6, 1979; no project application will be approved for assistance required to alleviate damage as a result of this major disaster occurring at any other-times. 5. In the event that funds arc to be transferred to the Ccr=onwealth of Puerto Rico for disaster relief purposes; the Commonwealth and its political subdivision, agree to the following: In the evcnL t1lat the Commonwealth of Puerto Rico or its political subdivisiori., Violate any of the con- 45 Page #2 dition3 imposed upon disaster relief assistance under Public Law 93-288, this Agreement, or applicable Federal Re ulations, the Director will notify the Commonwealth that additfonal financial assistance for the purpose of the project in connec tion with which.the violation occurred will be withheld until such violation has been corrected. Provided, ho@;ever, that the Di-rector, after such notice to Lhe Commonwealth, is not satisfied with the corrective measures taken to comply with his notification,the Director will notify the Commonwealth that fux:ther financial.assistance will be withheld-for the project for which it has been determined that a violation exists, or for all or any,portion of financial assistance which has or is to be made available to the Commonwealth or local governments for the purpose of disaster relief assis- tance under the provisions of Public Law 93-288, this Agree- ment, or applicant Federnl Regulations. 6. No member of or Delegate to Congress, or Resident Commis- sioner, shall be admitted to any share or part of this Agree- ment, or to any benefit to arise thereupon. Provided, how-- ever, that this provision shall -not be construed to.extend to any contract made with a corporation for its general benefit. 7. The Commonwealth officers authorized to execute certifi- cations and otherwise to act on behalf of the Commonwealth are listed in ExhibiL b which is attached hereto and made a part hereof. S. Federal assistance extcnded under Public Law 93-288 and this Agreement shall be limited to the following areas of the Commonwealth of Puerto Rica and such additional areas as may be subsequently designated by the Director of the Federal Emergency Management Agency. The Municipios of: Arecibo Humacao Arroyo Manati Barceloneta Ponce Toa Baja Dorado Vega Baja Juana Diaz GuAnica Jayuya Guayanilla Can6vanas Car6lina for Individual Assistance only. - 46 - Page 3 9. The state agrees: (1) to review and update as necessary disaster mitigations portions of the Commonwealth Emergency Plan; (2) that, as a condition for any Federal loan or grant, the applicant shall evaluate the natural hazards in the areas in which the proceeds of the grants or loans are to be used and shall take appropriate action to mitigate such hazards, including safe land use and construction practices; and (3) to foil up with applicants, within Commonwealth capabili- ties, to assure that appropriate hazard mitigation actions are taken. The Regional Director agrees to make Federal technical advice and assistance available to support these planning efforts and actions. 10. The Commonwealth will establish and maintain an active program under this Agreement of non discrimination in disaster assistance outlined in Part 2205.13, Title 24, CFR. This program will encompass all Commonwealth and local actions pursuant to this Agreement. 11. The Commonwealth will establish and maintain a program under this Agreement to assure that recipients of the FEMA Disaster Assistance comply with. 24 CFR, Part 24, Debarmant, Suspension and Ineligibility of Contractors and Grantees. This program will encompass all Commonwealth and local con- tracts pursuant to this Agreement. 12. The Commonwealth will notify all Commonwealth and local agencies and local goverments within the areas defined by this Agreement of the time limitations agreed to herein and the terms and conditions of eligibility for Federal assistance. 13. This Agreement may be amended at any time by written approval of both parties. Sincerely, Norman Sceinlauf Acting Regional Director Federal Emergency Management Agency Agreed: Governor Date - 47 APPENDIX B: HAZARD MITIGATION TASK FORCE AGENCY REPRESENTATIVE Commonwealth: Department of Natural Resources Gabriel Del Toro, Chairman Ruben Freyre Governors Authorized Representative for Juan Negron (P.R. Telephone Co.) State Civil Defense Agency Antonio V. Munera Puerto Rico Planning Board Boris Oxman Department of Transportation Rafael Torres Garcia and Public Works Department of Education Heriberto Capella Puerto Rico Aqueduct and Jose, R. Goitla Sewer Authority Department of Housing Cesareo Angelero* Francisco Hernan@dez** Regulations and Permits Administration Oscar Pi:Eeior* Telesfro Carrero** Puerto Rico Industrial Development Co. John Smith Municipios: Loiza Felipe Sanjurjo Carolina Roberto Bonilla Canovanas Miguel Del Valle Dorado Manuel J. Canino Toa Baja Antonio Rivera Federal: Federal Emergency Management Agency Curtis Carleton U.S. Army Corps of Engineers Emilio Colon National Weather Service Robert Calvesbert U.S. Geological Survey Karl G. Johnson U.S. Soil Conservation Service Oscar Perez Housing and Urban Development Arcadio Torres* Manuel Seone** *Original representative **Replacement APPENDIX C: HAZARD MITIGATION WORK GROUP AGENCY REPRESENTATIVE Department of Natural Resources Fe'lix I. Aponte, Chairman Ada Sotto Puerto Rico Planning Board Rafael Esteva Department of Transportation and Rene" Beauchamp Public works State Civil Defense Rcberto Martinez Nora Zenoni Federal Emergency Management Agency Eduardo Garcia* Ramon Martinez** Rafael Ramirez** U.S. Army Corps of Engineers Emilio colon . National Weather Service Robert Calvesbert *Original representative "Replacement APPENDIX D: SUMMARY OF RECOMMENDATIONS FROM PUERTO RICO FLOOD HAZARD MITIGATION PLAN FLOOD INSURANCE Flood Insurance for Privately_Owned Structures 1. Promote greater knowledge of the flood insurance program and its benefits through a program of increased public awareness. a. The Federal Insurance Administration and EDS Federal Corporation should more actively promote the sale of flood insurance in Puerto Rico. b. The Puerto Rico Planning Board and Department of Natural Resources should promote greater awareness of the flood insurance program as part of a general flood hazard aware- ness program. The following measures should be used: Radio Public notices in conspicuous places Television Banks Newspapers Professional and civic organizations Special Mailings 2. FIA should take administrative actions to lower the annual cost of a minimum flood insurance policy by extending the term of the policy from one year to two or three years. This action by FIA would make flood insurance more affordable to low income residents with low value properties. Insurance Renewal by Recipients of Disaster Aid 1. The Government of Puerto Rico should subsidize the cost of renewing minimum flood insurance policies for about 63,000 families currently insured under the Puerto Rico/FEMA Agreement covering beneficiaries of Individual and Family Grants. 2. Before these policies must be renewed, the Puerto Rico Department of Social Services and municipios should undertake an aggressive public awareness campaign, including direct mailing, personal visits to each household or business, or other appropriate measures to explain the danger of not maintaining adequate flood insurance. Insurance for Public.Buildings I 1. Government buildings should be insured against flood damages. How- ever, before purchasing flood insurance, an inventcry should be taken of public buildings located in floodable areas and of the value of buildings and building contents that should be insured. The costs and benefits to Puerto Rico or insuring these buildings and contents through the NFIP vs. establishing a qualified program of self-insurance should be evaluated. FLOODPLAIN REGULATIONS Enforcement of Planning Regulation Number 13 1. Before taking special measures to try and strengthen enforcement of Planning Regulation Number 13, a brief study of current implementa- tion of the regulation should be conducted in order to document the nature and extent of problems with enforcement. 2. Following completion of this study, the Planning Board, Regulation and Permits Administration, Department of Natural Resources and Department of Housing should prepare an Interagency Agreement de- tailing the responsibilities of each agency for surveillance and enforcement of Planning Regulation Number 13. 3. The Department of Natural Resources and the Department of Housing should make available personnel @_o assist with surveillance of floodplain activity in accordance with the Interagency Agreement recommended above. Revision of Planning Re_qulation Number 13 1. Planning Regulation Number 13 should be revised as needed to clarify its definitions and provisions and to make any other changes indicated by the study of present enforcement. Better Mapping of Flood Zones 1. The Planning Board should undertake to have all regulated flood zones mapped at a scale of 1:2,000 for urban zones and 1:4,000 for rural zones. 2. The Planning Board should identify the highest priority V-zones and make a request to FIA that Puerto Rico receive high priority for remapping those V-zones. Safe Construction and Reconstruction 1. To aid professional engineers and architects in designing and con- structing safe structures, the Regulation and Permits Administration, in cooperation with the U.S. Army Corps of Engineers, should prepare a manual describing floodproofing techniques acceptable for use in Puerto Rico. PLOOD FORECASTING AND WARNINGS 1. NOAA should take immediate steps, in coordination with the COE, U.S. Geological Survey (USGS), FEMA, and DNR, to develop and implement a fully automated flash flood warnings system, consisting of a radio network of event-reporting rain gages, repeater stations, river gages, and computer equipment. The initial cost is estimated at 1.5 to 2.0 million dollars (including $134,000 for the hardware for 56 rain gages and 31 river gages, and computer equipment). 2. The NWS should continue to work closely with Civil Defense Officials to improve data collection and dissemination of flood warnings. Tn particular, NWS should identify communities most vulnerable to flash floods, and maintain a continuing educational program for Civil Defense personnel on the potential for "worst case" versus "minimum" flood situations. 3. Plans for preparedness literature and films, whether done by NWS or FEMA, should recognize the special and unique needs of Puerto Rico and be designed accordingly. 4. A major NOAA weather radio publicity campaign should be initiated early in 1980 for Puerto Rico. EVACUATION PLANNING 1. The Civil Defense Agency and the CoE should perform a survey of flood hazard areas and determine, in order of priority, which areas are in the most danger from flooding or isolation during flooding and need detailed emergency evacuation plans. 2. The Civil Defense Agency, through its On-Site Assistance Program, and municipal civil defense directors should prepare evacuation plans for those areas determined to need formal emergency evacuation plans. As much as possible, these plans should be prepared similar to the ones being prepared by the Corps of Engineers for the R:ro Grande de Lofza and R1*o de La Plata coastal floodplains. 3. other agencies, such as DNR, the Geological Survey and the National Weather Service should assist in the preparation of these evacuation plans by providing funding and technical assistance. RELOCATION 1. A study of relocation needs and the social and economic impacts of relocation should be undertaken by the Department of Housing. The study should use data available from the 1980 census. 2. Federal funding assistance should be sought for the study as well as for subsequent implementation of any specific relocation program. FLOOD CONTROL STRUCTURES Construction of Additional Flood Control Structures 1. Puerto Rico should request the Corps of Engineers to conduct flood control studies for all densely developed areas located within regulatory floodways. Maintenance Of Existinq Flood Control Structures 1. The Puerto Rica Legislature should provide additional funding to the Department of Natural Resources (flood control section recently trans- ferred from DTPW) for increased maintenance of storm sewer systems, channelized streams and other flood control structures under common- wealth responsibility. Municipios should likewise increase funding for maintenance of storm sewers and local canals under their juris- diction. IMPROVED INFORAMATI0N ON FLOOD HAZARDS AND IMPACTS 1. Puerto Rico, federal and private agencies should collect and maintain information on flood damages and disaster assistance by municipios and socioeconomic areas. 2. The Department of Natural Resources should establish a central infor- mation repository that will contain and make available most information on flood hazards, flood damages, and emergency and disaster aid. 3. In order to ensure a complete and cc-sistent information base, the Department of Natural Resources should establish and provide to all concerned agencies clear and simple guidance, including development of appropriate forms, regarding the collection of data on flood damages and disaster assistance. PUBLIC AWARENESS 1. The Department of Natural Resources should establish a Public Aware- ness Program to coordinate the flood hazard public awareness activities of other agencies, and to prepare and distribute additional materials that are needed. HAZARD MITIGATION PLANNING Additional Hazard Mitigation Plans for Target Areas 1. Additional hazard mitigation plans should be prepared for high priority areas, especially for highly developed flood plains. Hazard Mitigation Planning Following the Next Declared Flood Disaster 1. The present Hazard Mitigation Task Force should be maintained as a functioning group to assist with the preparation of additional hazard mitigation plans and to help with the implementation of recommenda- tions included in this Puerto Rico Hazard Mitigation Plan and in the hazard mitigation plans for target areas. 2. The Department of Natural Resource , with the assistance of the Task Force, should prepare a set of det. :lcd procedurcs describing each agency's responsibilities for hazard mitigation planning. 3. FEMA should provide more specific guidance, greater technical assis- tance, and funding assistance for hazard mitigation planning. Hazard Mitigation Recommendations for Damage Survey__Reports 1. Public agencies should be required to implement the hazard mitigation recommendations contained in Damage Survey Reports in order to receive .9 @ederal disaster funds. Follow-up to Hazard Mitigation Recommendations Contained in Hazard-Mit-4- gation Plans and Damage Survey RcT)orts 1. The Department of Natural Resour'Ces should provide follow-up on recommendations and periodically rcport to the Governor on progress in implementation. M COASTAL SERVICES CTR LIBRARY ill 11111 111111111111111111 6668 14111100 7