    [From the U.S. Government Printing Office, www.gpo.gov]

                                                                        F?A

                                      PRINCE GEORGE'S COUNTY

                                                     MARYLAND

                                                       July 1981

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                                         Fnvironmental       Planning Division
                      THE MARYLAND-NATIONAL CAPITAL PARK AND PLANNING COMMISSION

                                         FLOOD DAMAGE INVENTORY

                                         PRINCE GEORGE'S COUNTY
                                                MARYLAND

                                                JULY 1981

                                     Environmental Planning Division
                       The Maryland-National Capital Park and Planning Commission

                                           FLOOD DAMAGE INVENTORY

                                           PRINCE GEORGE'S COUNTY
                                                  MARYLAND

                                                Prepared by:

                                     The Environmental Planning Division
                         The Maryland-National Capital Park and Planning Commission
                                       14741 Governor Oden Bowie Drive
                                       Upper Marlboro, Maryland 20772

                                                    for:

                                The Maryland Department of Natural Resources
                                          Tidewater Administration
                                         Coastal Resources Division

                                                     and

                                       Water Resources Administration
                                         Tawes State Office Building
                                         Annapolis, Maryland 21401

                THE MARYLAND-NATIONAL CAPITAL PARK AND PLANNING COMMISSION

                PRINCE GEORGE'S COUNTY PLANNING BOARD

                CHARLES A. DUKES, JR., Chairman
                EDWIN H. BROWN
                JOHN W. CHURCHILL
                JOHN H. CUMBERLAND
                ANN C. SHOCH

                                                         DEPARTMENT HEADS

                MONTGOMERY COUNTY PLANNING BOARD         THOMAS H. COUNTEE, JR.
                                                           Executive Director
                NORMAN L. CHRISTELLER, Chairman
                MABLE GRANKE                             A. EDWARD NAVARRE
                JUDITH B. HEIMANN                          Secretary-Treasurer
                BETTY ANN KRAHNKE
                SHELDON P. SCHUMAN                       ARTHUR S. DREA, JR.
                                                           General Counsel

                                                         JOHN F. DOWNS, JR.
                                                           Planning Director
                                                           Prince George's County

                                                         RICHARD E. TUSTIAN
                                                           Planning Director
                                                           Montgomery County

                                                         HUGH B. ROBEY
                                                           Director of Parks and Recreation
                                                           Prince George's County

                                                         STANTON G. ERNST
                                                           Director of Parks
                                                           Montgomery County

                                                         ROBERT D. REED
                                                           Community Relations Officer
                                                           Prince George's County

                                                         JOHN HOOVER
                                                           Community Relations Officer
                                                           Montgomery County

                Prince George's County Regional Office     Montgomery County Regional Office
                County Administration Building             8787 Georgia Avenue
                14741 Governor Oden Bowie Drive            Silver Spring, Maryland 20907
                Upper Marlboro, Maryland 20772

                                                  ii

                                             ACKNOWLEDGEMENTS

                    We would like to acknowledge the significant contributions made by
               those participating in the preparation of the Flood Damage Inventory.

                                       ENVIRONMENTAL PLANNING DIVISION

                                             Stan Udhiri, Chief
                                        Dominic J. Motta, Planner III*
                                         Wendell E. John, Planner I*
                                      Frances J. Guertin, Secretary III

                                      PLANNING DEPARTMENT ASSISTANCE

                                  Lauren Arth, Word Processing Operator IV
                                Charles Colella, Drafting Technician III
                           William Limpeft, Water Resources Planning Assistant
                                  Benetta Yeatman, Drafting Technician II

                         MARYLAND WATER RESOURCES ADMINISTRATION STAFF ASSISTANCE

                         Robert B. Dannecker, Chief, Flood Management Division
                               Mary Lou Soscia, Natural Resources Planner

              *Primarily responsible for the report.

                                                     Contents

                                                                                       Page

                SUMMARY    .....................................................         1

                1.0   Purpose of Study    ......................................         2

                      1.1   Background    ......................................         2
                      1.2 Authorization      ....................................        2
                      1.3   Coordination   .....................................         2
                      1.4   Methodology    .....................................         3

                2.0   County Description     ....................................        3

                      2.1 Location and Physiographic Description        ............     3
                      2.2 Major Watersheds       .................................       5

                3.0   Flooding Problems    .....................................         5

                      3.1   Countywide Discussion    ............................        5
                      3.2   Potomac River Sub-Watershed      ......................      9

                            3.21  Anacostia River   .............................        9
                            3.22  Beaverdam Creek   .............................      12
                            3.23  Oxon Run    ...................................      13
                            3.24  Henson Creek    ...............................      14
                            3.25  Piscataway Creek   ............................      15
                            3.26  Tinkers Creek    ..............................      15
                            3.27  Mattawoman Creek   ............................      17
                            3.28  Lower Potomac   ...............................      18

                      3.3   Patuxent River Sub-Watersheds      ....................    18

                            3.31  Upper Patuxent   ........ i .....................    18
                            3.32  Horsepen Branch   .............................      18
                            3.33  Western Branch    .............................      20
                            3.34  Collington Branch     ...........................    23
                            3.35  Charles Branch    .............................      23
                            3.36  Middle Patuxent   .............................      24
                            3.37  Lower Patuxent    .............................      24

                4.0 References     ..........  ...................................     27

                Appendix A - Sample Letter of Notification        ..................   A-1
                Appendix B - Highwater Elevation of Selected Prince George's
                                County Bri dges  .................................     B-1

                Appendix C - Selected Comments on Floodprone Properties          ..... C-1

                Appendix D - Inventory of Floodprone Structures         .............  D-1

                                                         iv

                                                        Tables                                  Page
                  1.    Structures Impacted by the 100-Year Flood
                        Prince George's County     .......................................       7

                                                        Figures

                  1.    Vicinity Map    ................................................         4
                  2.    Major Watersheds                                                         6
                  3.    Percentage of Flood-prone Structures by Watershed                        8

                  4.    Flood-prone Structures -
                          Anacostia River and Beaverdam Creek Watersheds       .............    10

                  5.    Percentage of Flood-prone Structures -
                          Anacostia.Sub-Watershed      ...................................      11

                  6.    Flood-prone Struct-ures -
                          Oxon Run/Watts Branch and Henson Creek Watersheds         .........   14

                  7.    Flood-prone Structures -
                          Piscataway Creek and Tinkers Creek Watersheds        .............    16

                  8.    Flood-prone Structures
                          Upper Patuxent     ...........................................        19

                  9.    Flood-prone Structures -
                          Western Branch and Collington Branch Watersheds         ...........   21

                  10.   Percentage of Flood-prone Structures
                          Western Branch Sub-Watersheds        .............................    22

                  11.   Flood-prone Structures
                          Middle Patuxent      ...........................................      25

                  12.   Flood-prone Structures -
                          Lower Patuxent    ...............................................    -26-

                                                           v

               Summary

                    This report contains an inventory and aerial cataloging of flood-prone
               properties in Prince George's County. On the basis of this study, a total
               of 11676 structures comprising 1,260 residential, 273 commercial and 143
               other structures are wholly or partially in the floodplain.

                    This inventory will serve as a pilot project for possible replication
               Statewide, to allow for assessment of the potential magnitude and frequency
               of flood damage in the State. The information contained in such an inven-
               tory will also help the State assess mitigation alternatives and priorities
               for governmental action.

                 1.0 Purpose of Study

                      The purpose of this study is to inventory and catalogue floodprone
                 properties in Prince George's County. This information will help the State
                 administer the Flood Management Grant Program and serve as a vehicle for
                 notifying the owners of floodprone properties of floodprone hazards, and
                 the relief available through federally subsidized flood insurance.

                 1.1 Background

                      Although 1 arge amounts of public funds have been spent in Maryland to
                 mitigate damage from periodic flooding, no concerted effort has been made
                 state-wide to collect, assess or distribute information on flood damages.
                 It is particularly discouraging that no comprehensive effort has been made
                 to notify the owners of potentially floodprone structures of the avail-
                 ability of federally subsidized flood insurance. In order to address this
                 situation, the Environmental Planning Division of the Prince George's
                 County Planning Board, in cooperation with the Maryland Water Resources
                 Administration and the Coastal Zone Management Program has undertaken an
                 inventory of flooding problems within the County. This "Flood Damage Data
                 Inventory" will serve as a pilot project for possible replication state-
                 wide. The informati-on gathered will result in an aerial cataloging and
                 filing system for storage and retrieval of flood damage information which
                 will allow assessment of flood damaged areas including history, average
                 annual damages, mitigation alternatives and priority for governmental
                 action.

                 1.2 Authorization

                      This study was prepared in accordance with Contract No. C4-78-440(81)
                 between the State of Maryland, Department of Natural Resources, Tidewater
                 Administration, Coastal Resources Division and the Maryland-National
                 Capital Park and Planning Commission - representing Prince George's
                 County.

                 1.3 Coordination

                      Interviews were conducted with staff of the Washington Suburban Sani-
                 tary Commission and the Department of Public Works. Information on flood-
                 ing due to stream overflows and inadequate drainage was sought from resi-
                 dents of the watersheds. A thorough review of available information on
                 flooding and inadequate drainage problems was also conducted to assist in
                 the identification of floodprone properties. Fortunately, a considerable
                 amount of information on flooding problems exists for Prince George's
                 County including U.S. Army Corp of Engineers Floodplain Information
                 Reports. Although some of these studies were performed over ten years ago
                 and are in need of updating, they do provide useful historical flood infor-
                 mation. In addition, some information is readily available from Stormwater
                 Management Studies and Comprehensive Watershed Management Plans being pre-
                 pared by the County's Storm Water Management Technical Group. Of particu-

                                                      2

               lar value was the report on Flooding prepared by the Prince George's County
               Task Force after the occurrence of Hurricane Agnes in June 1972.

               1.4 Methodology

                    In order to manage the flood data by geographic zones, the boundaries
               of major watersheds were delineated. Within each watershed, the best
               available floodplain delineation was used in conjunction with recent aerial
               photography and County Premise Address Maps to identify the location and
               address of floodprone properties. Since one of the principal purposes of
               the study is to notify property owners of the floodproness of their struc-
               tures, a conservative approach was used whereby all borderline structures
               were included in this initial inventory.

               2.0 County Description

               2.1 Location and Physiographic Description

                    Prince George's County is a 485 square mile jurisdiction which lies
               directly to the east and borders on Washington, D.C. The Patuxent River
               forms the northern and eastern boundaries of the County; while the Potomac
               River, District of Columbia and Montgomery County form the western bound-
               ary. Charles County lies directly to the south. The location of the
               County is shown in Figure 1.

                    The physical characteristics of the County are defined primarily from
               the underlying geology as altered by climatic and hydrologic conditions.
               Except for a small area along the Montgomery County boundary, Prince
               George's County lies almost entirely within the physiographic province
               known as the Atlantic Coastal Plain. The geology of the Coastal Plain con-
               sists of unconsolidated sediments of sand, silt, clay and gravel deposited
               upon the underlying crystalline rocks. The depth of these sediments
               decrease from east to west, thinning out in a wedgelike manner near the
               border between Montgomery and Prince George's Counties.

                    The northern part of the Coastal Plain in Prince George's County is
               gently rolling and has broad valleys. The remainder is a partly dissected
               4-ow-pl-a_teau that extends into Charles County. Near the Patuxent and
               Potomac Rivers this plateau is cut by V-shaped valleys that have short,
               steep slopes. Elevations range from sea level along the lower reaches of
               the major rivers to over 400 feet in the northernmost portion of the County
               near the Rocky Gorge Reservoir.

                    All the major streams in the County are normally  sluggish and most are
               in broad valleys. Because coastal plain soils are highly erodible, silta-
               tion is a major problem. The wide valleys with extensive floodplains also
               lead to considerable flooding problems during major storm events.

                                                    3

                                    F I GURE                    I           LOCATION OF PRINCE GEORGE'S COUNTY, MARYLAND

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                                                                                                                                 4

                2.2 Major Watersheds

                     Prince George's County is divided almost equally between two major
                river basins, the Potomac River which occupies the western half of the
                County and the Patuxent River which occupies the eastern half. The Potomac
                River Basin is largely urbanized and contains most of the existing residen-
                tial, commercial and industrial development in Prince George's County. The
                Patuxent River, on the other handt is still mostly rural and is dominated
                by agricultural land uses.

                     For the purpose of watershed planning and to facilitate a discussion
                of flooding problems,.each River Basin has.been divided into major sub-
                watersheds as follows:

                Potomac River Basin                         Patuxent River Basin

                Anacostia River                             Upper Patuxent
                Beaverdam Creek                             Horsepen Branch
                Oxon Run                                    Western Branch
                Henson Creek                                Collington Branch
                Piscataway Creek                            Charles Branch
                Tinkers Creek                               Middle Patuxent
                Lower Potomac                               Lower-Patuxent

                     The location of these sub-watersheds  is identified on Figure 2. A
                complete description of each sub-watershed is included in Section 3.0 under
                flooding problems.

                3.0 Flooding Problems

                3.1 Countywide Discussion

                     As land uses in Prince George's County have changed from rural agri-
                cultural and forest uses to urban and suburban subdivisions, shopping
                centers and employment parks, the impact of flooding has gradually
                increased. Although floodplain encroachments have been minimized in recent
                years by strong local regulation, occasional conflicts still occur due to
                changes in stream hydrology and hydraulics and changes in the definition of
                the regulated floodplain. The effect of changing land uses on flood damage
                was brought into sharp perspective on June 22, 1972, when tropical storm
                Agnes struck and left in its wake damage and disruption unequalled by
                previous storms. Agnes caused more than $10 million in damage in Prince
                George's County and resulted in a heightened-appreciation of the power of
                floodwaters.

                     Because most of the development in Prince George's County has occurred
                in the Potomac iRiver Basin near Washington, D.C. the majority of the flood-
                ing problems have also occurred in this basin, particularly in the Anacos-
                tia sub-watershed. Our inventory has identified a total of 1,646 flood-
                prone structures including 1,209 in the Potomac River Basin and 439 struc-
                tures in the Patuxent River Basin. While 86% of the flood-prone residen-
                tial structures are located in the Potomac Basin only 48% of the flood-

                                                     5

                            FIGURE 2                                           WALKER BRANCH
                            PRIORITY         WATERSHED,@                              BEAR BRANCH
                                       FOR
                           PRINCE GEORGES
                                  COUNTY
                                                                                                     R
                                                                                                          NT
                                                                     RV                                          HORSEIPEN
                                                                                                                 BRANCH

                                                                                                               I       E

                                                                                                                        UXENT

                                                                                           ST

                                                                                                       Co

                                                 OX0.          U

                                                       HE
                                                       EK_'    Tt*KE
                                                                                               ANO

                                                                        Is

                                                                   R
                                                                                                    E

                                                                                                   fbD

                          POT.                        T              N. C E

                                                                 BASIN OMPE

                                                                 SUB-BASIN DIVIDE

                                                                      -6-

                               Irf-TM MAWAAM-NAMM CAMAL MM NO RANNOW CQ*MSMM

                         SOMM  MARYLAM 06OL00" SUn" TOPOMA"NC MM

                                                      Table 1

                                     Structures Impacted by 100-Year Flood

                                                                Structures
                Watershed                Total     Residential       Commercial-     Other

                Anacostia                  811           721             78              12
                Beaver Dam Creek            97            65             31              1
                Oxon Run                     9             9               -             -
                Henson Creek               203           188             11              4
                Piscataway Creek            73            71               1             1
                Tinkers Creek               44*           34*              9             1
                Lower Potomac                -             -               -             -

                Total Potomac            1,239          1,088            130             19

                Upper Patuxent              79            30             49              -
                Horsepen Branch              -             -               -             -
                Western Branch             324           ill             93            120
                Collington Branch           16            11               1             4
                Charles Bra-nch              -             -               -
                Middle Patuxent              6             6
                Lower Patuxent              14            14               -             --

                Total Patuxent             439           172             143           124

                Total County              12676         1,260            273           143

                    Includes 30 trailer homes

                                                                                            FIGURE 3
                     PERCENTAGE OF.FLOODPRONE STRUCTURES
                                        MAJOR WATERSHEDS

                                                     Anacostia
                                                         48%

                                                      0 0000000
                                                  0000 0000000000
                                                0000000 0000000000000
                                             000000000 00000000000000
                                            0000000000000000000000000000
                                           000000000000000000000000000000
                                         00000000000000000000000000000000
                                        000000000000000000000000000000000
                                       0000000000000000000000000000000000 00
                                       0000000000000000000000000000000000 00
                                     000000000000000000000000000000000000 000
                                     00000000000000000000000000000000000000000
                                    000000000000000000000000000000000000000000
                                    0000000000000000000000000000000000000000000o
                                   000000000000000000000000000000000000000000000
                                   0000000000000000000000000000000000000000000oo
                                  0000000000000000000000000000000000000000000000
                                  00000000000000000000000000000000000000000000000
                                  00000000000000000000000000000000000000000000000
                                  000000000000000000000000000000000000000000000000
                                 000000000000000000000000000000000000000000000000
                                  0000000000000000000000000000000000000000000        Collington Br.
                                 000000000000000000000000000000000000
                                 00000000000000000000000000000
                                             ----------                                    1%

                 Beaver Dam Cr.
                         6%

                         Oxon Run
                                                                                   Western Br.
                                                                                        01
                            1%                                                        19,0
                                                     ANN\+
                                                      \N\
                                                      \N\ +
                                                         +

                                                         +
                             Henson Cr.                   +
                                 12%                    + +
                                     Piscataway Cr.     + +         Patuxent
                                           4%@       Tinkers Cr.      6%
                                                          3%

                                                      8

               prone commercial structures are located there. The majority of the flood-
               prone commercial structures are located in the City of Laurel in the Upper
               Patuxent sub-watershed. Table 1 identifies the number of structures by
               type and watershed impacted by the 100 year flood in Prince George's
               County. The percentage of flood-prone structures by watershed is dia-
               grammed in Figure 3.

               3.2 Potomac River Sub-Watersheds

               3.21 Anacostia River Watershed

                    The Anacostia River Watershed is 120 square miles with 68 square miles
               of the lower portion within Prince George's County and the remainder in
               Montgomery County. The entire watershed has been designated a State Scenic
               River and is currently being studied under this program. The two main
               tributaries of the Anacostia are Northeast and Northwest Branches. These
               tributaries originate in the Piedmont in Montgomery County, cross the fall
               line onto the Coastal Plain and merge into a tidal estuary near the D.C.
               line. Land use within the watershed is varied with the lower reaches
               inside the Capital Beltway heavily developed with 6 mixture of residential,
               commercial, industrial and institutional uses. Outside the Beltway, the
               watershed is less developed with the Beltsville Agricultural Research
               Center making up a large area of agricultural and forestry uses. An exten-
               sive stream valley park system provides recreational and open space bene-
               fits to large numbers of County citizens.

                    Because much of the Anacostia River Watershed is heavily developed,.
               numerous flooding problems exist. A total of 811 structures have been
               identified within the watershed including 721 residential structures, 78
               commercial and 12 other structures. Figure 4 identifies the approximate
               location of these flood-prone structures. Six major tributaries contribute
               to the flow of the Anacostia River. These are: Northwest Branch, Sligo
               Creek, Northeast Branch, Indian Creek, Paint Branch and Little Paint
               Branch. The relative severity of flooding in each of these tributaries is
               shown in Figure 5.

                    Northwest Branch and its tributary Sligo Creek were probably the
               hardest hit streams in the watershed during the flood resulting from Trop-
               ical storm Agnes in June 1972. Damages were particularly severe in the
               communities of Lewisdale, Riggs Manor and Chillum where over 200 homes
               were flooded. Other flood-prone areas include the region around the Queens
               Chapel and Queenstown shopping complex and the Queenstown Apartments. The
               major floodprone areas in Northeast Branch include Riverdale and East
               Riverdale. In the Paint Branch and Little Paint Branch watersheds serious
               flooding occurs in Lakeland, the Cherry Hill Subdivision and areas along
               Route 1. A significant number of floodprone properties are found along
               Indian Creek in Beltsville Heights, Greenwood Road, Somerset Avenue,
               Springhill Lake, Old Branchville Road and Berwyn Heights.

                                                  - 9 -

                                                       FIGURE 4

          ANACOSTIA RIVER & BEAVERDAM CREEK WATERSHEDS
            STRUCTURES IMPACTED BY 100 YEAR FLOODPLAIN

                                                                                      \@NCRTH

                                            N. COSa IA I

                                          29           8

                                            24    6

                                                 29

                                 66           Is

                              111 972

                              124

                                                  22

                                                 2
                                  14 so 469                   /0000    2
                                                                   6

                                                               10
                                                             2

                                                                                   CREEK

                                                                               LEGEND:

                                                                                  RESIDENTIAL STRUCTURES
                                                                              k
                                                                                   COMMERCIAL STRUCTURES
                                                                                   lINDICATES NUMBER OF
                                                                                   BUILDINGS

                                                                                                      FIGURE 5

                     PERCENTAGE OF FLOODPRONE                                      STRUCTURES
                                 ANACOSTIA SUB-WATERSHEDS

                                  Northwest Br.
                                        39%

                                                  ..........

                                                                                            Indian Cr.
                                                                                                 9%

                                                          ........ .                      00
                                                                                   0000000
                                   ......                                    0000
                                  . ....                                            00000 0
                                                                     00000        0
                                                                             00000000 000
                                                                    000900010000000000000
                                                         rA             0 )0
                                                                      0 0 0000000000000
                                                                        000000000000000       Paint Br.
                                      A' e                  A joA         000000 0 0
                                        >                                     000   000   00
                                                                                00                9%
                                                                                  00000 0
                                                                                  0000000

                                                 <A4              v

                                           b  A A                  A
                                                       7                                 rtheast Sr.
                             Sl i go Br .    1, ,  > "I -.
                                             ,. % 3- r .'
                                 30%             7  , , 4  r                                13%
                                                    P..A 'A ,
                                                     A 1       7, "'r
                                                         A 4  4 c f.
                                                                   4

                       In response to the known flooding problems in the Anacostia Watershed,
                  a number of projects have been developed or are planned to alleviate some
                  of the worst flooding problems and prevent an increase in flooding in the
                  future. Many of these projects were initiated by the U.S. Army Corps of
                  Engineers in coordination with the WSSC and include the realignment and
                  excavation of reaches on Sligo Creek, Northwest Branch, Paint Branch,
                  Indian Creek, Northeast Branch and the Anacostia River. Other flood con-
                  trol projects within the watershed include earthen levees, storage ponds,
                  impoundments, reconstructed bridges and pump stations for the conveyance of
                  stormwater. Two major flood control projects are currently included in the
                  WSSC CIP (Capital Improvement Program) for Northwest Branch at Allison
                  Street in Brentwood and for Indian Creek in Beltsville. When these two
                  projects are completed, approximately 236 structures will no longer be
                  impacted by the 100 year flood. Prince George's County plans to initiate a
                  Comprehensive Watershed Management Plan for this watershed in FY 1983 to
                  further address present and future flooding problems.

                  3.22 Beaverdam Creek Watershed

                      The Beaverdam Creek Watershed which consists of approximately 16
                  square miles of land area is adjacent to the District of Columbia and south
                  of the Baltimore-Washington Parkway. Much of the basin is already devel-
                  oped with a considerable number of commercial and industrial establish-
                  ments. A major highway (Route 50), the Penn Central Railroad, and a Metro
                  Transit line all closely parallel the mainstem of Beaverdam Creek.

                      Flooding problems occur along the mainstem of Beaverdam Creek and its
                  major tributaries, Cabin Branch and Cattail Branch. The major problems are
                  due to loss of natural storage from floodplain encroachment and increased
                  runoff from major graded, paved and piped or channelized reaches. Loss of
                  conveyance due to obstructions, debris and sedimentation and undersized
                  bridge openings also add to flood stages. Ninety-seven (97) structures
                  were identified by this survey as potentially floodprone, including 65
                  residential structures and 32 commercial or other structures. Figure 4
                  identi.fies the general location of flooding problems in the Beaverdam Creek
                  Watershed. The most serious flooding dccurs in the lower portions of the
                  watershed in the north Englewood section of Cheverly, Beaverdam Estates,
                  Beaver Road Industrial Area, Columbia Park and Tuxedo Industrial Area.
                  Flooding also occurs in Palmer Park along Cattail Branch and in Carmody
                  Hills and Cedar Heights along Cabin Branch.    I

                      Because the watershed is already heavily developed., the County has
                  been pursuing a site specific approach to manage the increased stormwater
                  flows, instead of developing a Comprehensive Watershed Management Plan.
                  The site specific approach, however, will not alleviate existing flooding
                  conditions. Consideration is therefore being given to initiating a Compre-
                  hensive Watershed Management Plan in FY 1983.

                                                      12

                3.23 Oxon Run and Watts Branch Watershed

                     Oxon Run is a 14 square mile watershed. It drains the area inside the
                Beltway at the southern portion of the Prince George's County that borders
                the District of Columbia. Approximately 10 square miles of the watershed
                are located in Prince George's County. The small Watts Branch Watershed
                which drains from Capitol Heights and Maryland Park towards the District of
                Columbia, is also included as part of Oxon Run in this inventory. Despite
                being the most completely developed watershed in Prince George's County
                with primarily residential land uses, Oxon Run has been one of the more
                successfully managed urban streams in Prince George's County. Much of the
                downstream portion of Prince George's County has been protected from inten-
                sive development by parkland, cemetery and other open space uses. This has
                helped to minimize flood damages in the past; however, floodplain encroach-
                ment and channelization within the cemeteries may have an adverse impact in
                the future on properties further downstream.

                     Nine (9) residential structures have been identified as being prone to
                flooding from a 100 year storm. These residences are located on Green
                Valley Drive in Suitland on Oxon Run, and Drum Avenue on Watts Branch.
                Figure 6 identifies the general location of flood-prone structures in the
                watershed.

                     Because Oxon Run is already highly developed and flood damages minor,
                no comprehensive watershed study has been completed or is scheduled in the
                near future. The County's watershed management approach will continue to
                be site specific. New development will be evaluated on an individual basis
                to minimize the*effects of increased flows and corrective projects will be
                constructed where a need is demonstrated.

                3.24 Henson Creek Watershed

                     Henson Creek is a 25 square mile watershed located in southwest Prince
                George's County. The creek originates near Andrews Air Force Base and dis-
                .charges into an embayment on the Potomac River. Considerable residential
                development, both single- and multi-family, has already occurred in the
                upper portions of Henson Creek. The remainder of the basin is gradually
                developing in single-family residential uses. Future industrial develop-
                ment near Andrews AFB and a proposed Metro station will spur additional
                development in the watershed. Although Henson Creek is relatively small in
                size in relation to the other major watersheds in the County, it has had
                more than its share of flooding problems. A total of 191 structures has
                been identified as flood-prone within the watershed including 176 residen-
                tial structures, 11 commercial and 4 other structures. Figure 6 identifies
                the general location of these flood-prone properties. The upper portion of
                the watershed, which is generally flat, has experienced considerable devel-
                opment, some of which has encroached on the floodplain. The most serious
                flooding problems in this portion of the watershed have occurred along
                Woodland Road, Weldon Drive, Keppler Road and Beachcraft Court. The lower
                portion of Henson Creek has some special flooding problems. Several tribu-
                taries including Hunters Mill Branch, originate on old alluvial terraces

                                                  - 13 -

                                                      FIGURE 6

                     OXON RUN & HENSON CREEK WATERSHEDS
            STRUCTURES IMPACTED BY 100 YEAR FLOODPLAIN

                                                    Ox

                                                                     0
                               @NO R T H                                   CA

                                                                     2

                                                    95             9

                                                                17
                                              HEN            C

                                                        lop

                                               6                      LEGEND;
                                                                      Q RESIDENTIAL STRUCTURES

                                                                     15 CCMMERCIAL STRUCTURES
                                                                      kINDICATES NUMBER OF
                                                                          BUILDINGS

                                                     -14 -

                along the Potomac River and cut V-shaped valleys with short, steep slopes.
                These streams generate'high flash runoffs and erosion problems which result
                in sedimentation and flooding conditions when level areas and inadequate
                culverts are encountered. This problem is particularly severe due to back-
                water effects at Indian Head Highway. Below Oxon Hill Road, Henson Creek
                is re-named "Broad Creek" and is a wide flat stream under tidal influence
                where much of the sediment load from the entire system is deposited.

                     Past efforts to control flooding within the watershed include several
                small channelization projects. In particular, a flood channel constructed
                along the main stem in the vicinity of Woodland Road should help to
                decrease flooding in this area. The current WSSC CIP includes a project to
                alleviate the flooding along Weldon Drive. A Comprehensive Watershed
                Management Plan for the Henson Creek Watershed has been initiated and will
                be completed during FY 1982. This Plan will address the stormwater manage-
                ment and erosion control problems and will recommend solutions to present
                and future flooding problems.

                3.25 Piscataway Creek Watershed

                     Piscataway Creek is a 67 square mile watershed located in Southern
                Prince George's County. Rising on Andrews AFB, the creek flows in a south-
                westerly direction, discharging into a large eimbayment on the Potomac. Of
                its 67 miles of land area, 17 are included in the Tinkers Creek Watershed
                which will be discussed separately. Much of the watershed remains in rural
                land uses with scattered residential subdivisions. Most of this develop-
                ment occurs in the north central portion of the basin along Md. Route 5.
                Because development has not progressed as rapidly as expected, flooding
                problems have not been severe in this watershed. However, development in
                the upper portions of the Piscataway Creek Watershed is expected to in-
                crease significantly in the future, and could generate more flooding prob-
                lems in the middle and lower portions of the basin. This survey identified
                73 structures which are potentially prone to flooding during the 100 year
                storm including 71 residential structures I commercial structure and I
                other structure. Figure 7 identifies the general location of these struc-
                tures.

                     The most serious flooding problems within the watershed are on the
                lower portion of the mainstem along Livingston Road, Floral Park Road and
                in the lower portions of Windbrook Subdivision. Further upstream, the
                Clinton Acres Subdivision is also subject to flooding problems.

                     In order to address the problems of present and future flooding, a
                Comprehensive Watershed Management Plan has been initiated for the Piscat-
                away Creek Watershed. This Plan will be completed during FY 1983.

                3.26 Tinkers Creek Watershed

                     Tinkers Creek is a 17 square mile watershed, which is a majorr tr'ibu-
                tary of Piscataway Creek. The two major tributaries of Tinkers Creek,

                                                      15

                                                    FIGURE 7

           TINKERS CREEK &PISCATAWAY CREEK WATERSHEDS
             STRUCTURES IMPACTED BY 100 YEAR FLOODPLAIN

                                   RTH                                         ki,

                            TINKER                                   CATAWA               -R

                                           15

                                            LEGEND:
                                            (D RESIDENTIAL STRUCTURES
                                           k
                                            5 COMMERCIAL STRUCTURES
                                               lINDICATES NUMBER OF
                                                BUILDINGS

                                                          16

                Meetinghouse Branch and Pea Hill Branch originate on Andrews AFB and flow
                in a southwesterly direction for above @ive miles to their confluence with
                the main Creek, which continues for about another five miles before meeting
                Piscataway Creek. Land use within the watershed is primarily residential
                with a considerable amount of undeveloped land remaining.

                     A total of 14 structures have been identified within the       Tinkers Creek
                Watershed as being flood-prone'during a 100 year storm. This        total
                includes 4 residential structures and 9 commercial structures       and 1 other
                structure. Figure 7 identifies the general location of these        flood-prone
                properties.

                     The most severe flooding occurs along Coolridge Drive in       the Coolridge
                Subdivision. For the 100 year flood, as many as eight existing structures
                will experience varying levels of flooding. There is an isolated home and
                two other structures located north of Southeast Trailer Park that are also
                flood-prone. In the western section of Southeast Trailer Park, across from
                Temple Hill Estates, approximately 30 trailer homes are within the 100 year
                flood limits. Because of the type of structures involved, the effect of
                flooding could be more severe than with conventional structures. On the
                northern end of the Rose Valley Airport runway, two commercial structures
                are within the floodplain limits. A number of roads and bridges within the
                watershed are also susceptible to flooding.

                     Tinkers Creek was the first basin to be studied by the Prince George's
                County Stormwater Management Technical Group. A Technical Data Base Report
                and Watershed Management Plan were completed in 1980 which addresses storm-
                water management and erosion control needs in the watershed. The recom-
                mended plan consists primarily of constructing three dry ponds within the
                Andrews AFB, one behind Georgia Avenue and a second at Branch Avenue both
                in Meetinghouse Branch and a third behind Branch Avenue and Paynes Branch.
                Together, the three detention ponds will remove all homes and commercial
                buildings within Tinkers Creek from the 100-year floodplain. They will
                also reduce the extent and frequency of flooding of roads and bridges.
                Thi-s project has been adopted by Prince George's County and included in the
                Capital Improvement Program. -The project is expected to be completed by FY
                1983.

                3.27 Mattawoman Creek

                     Mattawoman Creek forms a major portion of the boundary between Prince
                George's and Charles Counties, with approximately 24 square miles of the
                watershed located in Prince George's County. Land use within the Prince
                George's County portion of the watershed is predominantly rural with scat-
                tered low-density residential, agricultural and forestry uses. Current
                plans, however, call for major residential, commercial and industrial
                development in the area adjacent to Route 301. Most of the existing devel-
                6pm@ent and subsequent flooding problems within the watershed occur in
                Charles County where several subdivisions encroach on the floodplain.
                Except for road flooding, the Prince George's County portion of the water-

                                                      - 17

                  shed seems to be free of flooding problems. No structures were identified
                  by this survey.  The Maryland Water Resources Administration i@ currently
                  delineating the 100-year floodplain for this watershed. A Comprehensive
                  Watershed Management Plan is not currently programmed for Prince George's
                  County.

                  3.28 Lower Potomac

                      The Lower Potomac consists of a number of small watersheds directly
                  tributary to the Potomac River in the southwest portion of Prince George's
                  County below Piscataway Creek. This area is sparsely developed and flood-
                  plains have not been delineated. No structures were identified by this
                  survey as flood-prone in this area.

                  3.3 Patuxent River Sub-Watersheds

                  3.31 Upper Patuxent

                      The Upper Patuxent consists of the Patuxent River and its tributaries
                  from the Rocky Gorge Reservoir to the confluence with Horsepen Branch.
                  A considerable amount of development has occurred in the upper porti 'on of
                  this area which includes the City of Laurel. The area below the Baltimore-
                  Washington Parkway is largely within the Patuxent Wildlife Research Center
                  where floodplain disturbance is prohibited. Severe flooding has occurred
                  in the City of Laurel on 5 occasions since 1933, including the most spec-
                  tacular flooding in Prince George's County during tropical storm Agnes in
                  June 1972. The most serious flooding occurs in a 4,600 foot long reach
                  from just upstream of U.S. Route 1, south to Maryland Route 198. Numerous
                  commercial properties including Laurel Race Track, Laurel Plaza Shopping
                  Center, Laurel Pines Golf Course, WLMD radio broadcasting station and
                  Montpelier Plaza Shopping Center are subject to flooding during the 100
                  year storm. A total of 79 structures have been identified within the
                  Upper Patuxent area as subject to flooding including 30 residential struc-
                  tures and 49 commercial or other structures. Figure 8 identifies the
                  general location of floodprone structures within the watershed.

                      Very little can be done to reduce flooding potential on the Upper
                  Patuxent. The WSSC has adopted a policy of operating its water supply
                  reservoirs above Laurel with flood control in mind as well as water supply
                  and to carefully monitor upstream storm events in order to allow earlier
                  and more gradual release of flood peaks. This should help to decrease the
                  severity of flooding.

                  3.32 Horsepen Branch

                      The Horsepen Branch Watershed comprises approximately 6.5 square miles
                  of land area in the vicinity of Bowie.. Maryland. Land use within the basin
                  is primarily residential. The Town of "Old Bowie" is centrally located
                  within the watershed, with more recently developed residential subdivisions
                  scattered throughout the area.

                                                      18

                                                FIGURE 8

                             UPPER PATUXENT WATERSHED
          STRUCTURES IMPACTED BY 100 YEAR FLOODPLAIN

                                     T@ HOWARD DUCKETY

                                                10

                                       "AMC"

                                                                             '\,,,@NORTH

                                              UP       R P          X T

                                                             lie

                LEGEND:

                   RESIDENTIAL STRUCTURES

               15 COMMERCIAL STRUCTURES
                kINDICATES NUMBER OF
                    BUILDINGS

                                                      19

                      The 100 year floodplain of Horsepen Branch has not been delineated and
                  the entire watershed has been identified as Zone "C" on the FIA map. For
                  this reason and because very little development has occurred in the vicin-
                  ity of the mainstem, no structures have been identified as flood- prone.
                  Several tributaries to Horsepen Branch do cross under the Pennsylvania
                  Railroad through inadequate culverts, which creates the potential for back-
                  water flooding.

                  3.33 Western Branch Watershed

                      The Western Branch Watershed is the largest watershed wholly within
                  the County, comprising 70 square miles of land area. Most of the watershed
                  lies outside the Beltway; however, a portion is located inside the Beltway
                  in the Forestville area. Land use in Forestville is a mixture of residen-
                  tial., commercial and industrial. Outside the Beltway, the basin is charac-
                  terized by rural land uses, with residential development concentrated along
                  Central Avenue and in the upper reaches of the watershed along Bald Hill
                  and Folly Branches.

                      Most of the streams within the Western Branch Watershed-have flat
                  gradient and sluggish flows. The overbank areas are also flat and in many
                  sections marshy. For these reasons, periodic flooding from stream'overflow
                  occurs along most of the mainstem and tributaries.

                      A total of 324 structures has been identified within the Western
                  Branch Watershed as being flood-prone during a 100 year storm under full
                  development. This total includes 111 residential structures, 93 commercial
                  and 120 other structures. Figure 9 identifies the general location of
                  flood-prone structures within the watershed.

                      Several major sub-watersheds contribute flow to the mainstem of
                  Western Branch. The most severe flooding occurs in the two uppermost sub-
                  watersheds along Folly and Bald Hill Branches. In these sub-watersheds a
                  combination of floodplain encroachment, stream siltation and backwater
                  effects from inadequate structure openings increase the incidences of
                  flooding. Fifty (50) of the 111 flood-prone residential structures are
                  located within these watersheds. There have been reports of frequent
                  flooding of commercial and residential properties along Lanham-Severn Road,
                  Wellington Place, 4th, 5th, and 6th Streets, adjacent to Bald Hill Branch.
                  Another area of potential flooding is along Southwest Branch where roads
                  are frequently closed by flood water, and some residential and commercial
                  developments were built on flood-prone land. Fifty (50) structures includ-
                  ing 20 residences are located within the Southwest Branch floodplain. The
                  flooding is particularly severe at Hampton Mall near Central Avenue and
                  Route 495. Figure 10 represents the distribution of flood-prone structures
                  among the sub-watersheds of Western Branch.

                      Along-the'n.ainstem of Western Branch, flooding potential is most
                  severe in the Town of Upper Marlboro where 89 structures have been identi-

                                                    - 20 -

                                                                                                                                                                                                                  FIGURE 10

                                        PERCENTAGE OF FLOODPRONE STRUCTURES
                                                       WESTERN BRANCH SUB-WATERSHEDS

                                                        Western Main Stem
                                                                         41%

                                                                                                                                                                                             Back Br. 1%
                                                                                                                                                                               00000              urkey Br.
                                                                                                                                                                          00                            2%
                                                                                                                                                                   00

                                             Cabin Br.
                                                         C/                                            V 7       r
                                                      210
                                                                                                                                                                                                    Southwest Br.
                                                                                                                                   +
                                                                                                                                      +
                                                                                                                                +                                                                               164
                                                                         -7                                                        +
                                                                                                          q   IC   1,  .*.*.
                                                                                                          ), @L       . ...     +     +
                                                                                                 I r
                                        Bald Hill Br.
                                                                                                                                +     +
                                                     13%                           r          -'t  AC A                     +      +     +
                                                                                                                                +     +     +
                                                                                                                      +     +      +
                                                                                                                                                                                         Northwest Br. 201
                                                                                                                                                                                                                               /0

                                                                                                                                                                                  Lottsford Sr. 1%
                                                   Federal Spring Br.
                                                                               4%                           . . . . . . .                                              Collington Br.
                                                                                                                                   Folly Br.                                         6%
                                                                                                                                         12%

                                                                                                                            22

                 fied as flood-prone.   Several road crossings on the mainstem are closed for
                 many hours each year due to overtopping.

                      Past efforts to control flooding within the watershed included con-
                 struction in December 1964 of a local levee system along the mainstem near
                 the Town of Upper Marlboro. A comprehensive Watershed Management Plan is
                 currently being prepared for Western Branch. This Plan, when completed,
                 will address stormwater management problems and erosion control needs and
                 will recommend solutions to present and future flooding problems.

                 3.34 Collington Branch Watershed

                      The Collington Branch, a major contributary to Western Branch, has a
                 long, narrow 23 square mile watershed which parallels the west side of
                 Route 301 from Bowie to Upper Marlboro. Land use varies from single-family
                 residential in the vicinity of Bowie to rural and agricultural uses
                 throughout much of the remainder of the basin. A major industrial park is
                 planned for a portion of the basin just south of Route 214. The watershed
                 has remained mostly undeveloped and floodplain encroachments have been
                 minimized. A total of 16 structures have been identified within the water-
                 shed as potentially flood-prone during a 100 year storm under full develop-
                 ment. This total includes 11 residential structures 1 commercial and 4
                 other structures. in addition, 7 road crossings are wholly or partially
                 within the floodplain; however, none of the major transportation arteries
                 would be affected. Figure 9 identifies the general location of the flood-
                 prone structures.

                      The most severe flooding within the waterhsed occurs near the conflu-
                 ence of Collington and Western Branches where 8 residential and commercial
                 structures have been identified as flood-prone. Flooding of these struc-
                 tures would be due primarily to the backwater effect from high stages in
                 Western Branch.

                      The U.S. Army Corps of Engineers completed a flood control project,
                 consisting of floodwalls and channel improvements in 1964, near the-Town of
                 Upper Marlboro. There are no other flood protection measures within the
                 watershed. A Comprehensive Watershed Management Plan is currently being
                 prepared for Collington Branch. This Plan, when completed, will address
                 stormwater management problems and erosion control needs. It will also
                 recommend solutions to present and future flooding problems.

                 3.35 Charles Branch

                      Charles Branch is an 18 square mile watershed located east of Andrews
                 AFB and south of Route 4. Charles Branch discharges into Western Branch
                 near its confluence with the Patuxent River. Land use within the basin is
                 primarily agricultural with a few scattered residential subdivisions. One
                 large subdivision, Marlton has developed to the east of Route 301. The
                 suburban development which has occurred in the watershed has been recent
                 enough to be regulated so as to avoid floodplain encroachment. The 100

                                                    - 23 -

                year floodplain has not been delineated and the watershed is identified as
                Zone "C" on the FIA maps.     This survey did not reveal any structures within
                the watershed prone to flooding. A Comprehensive Watershed Management Plan
                for Charles Branch has not been prepared; however, one will be initiated in
                FY 83.

                3.36 Middle Patuxent River

                      For the purpose of this survey, the Middle Patuxent is defined as the
                area along the Patuxent River from its confluence with Horsepen Branch to
                its confluence with Western Branch. The floodplain in this area is largely
                undisturbed except near Priest Bridge. This survey identified 6 residen-
                tial structures within the 100 year floodplain. Figure 11 identifies the
                general location of these flood-prone areas.

                      Most of the flood-prone structures are located in the vicinity of
                Priest Bridge.

                      Very little can be done to control flooding in these areas except to
                prevent further encroachment in the floodplain and to minimize erosion to
                preserve existing channel capacity.

                3.37 Lower Patuxent River

                      The Lower Patuxent Area is defined for the purpose of this study as
                the Patuxent River and its tributaries south of the Western Branch Water-
                shed. This area is almost entirely rural with only scattered low-density
                development. The only exceptions are the Nottingham and Eagle Harbor com-
                munities and the Chalk Point Power Plant near the southeast tip of Prince
                George's County. Our survey did identify a total of 15 residential struc-
                tures including 12 in Eagle Harbor as subject to potential flooding during
                a 100 year storm event. Figure 12 identifies the location of flood-prone
                structures in the Lower-Patuxent Area.

                                                        24

                                                    FIGURE 11

                              MIDDLE PATUXENT WATERSHED
            STRUCTURES IMPACTED BY 100YEAR FLOODPLAIN

                                                                           @@NCRTH

                                           MID                            T

                                                                             LEGEND:
                                                                             Q RESIDENTIAL STRUCTURES
                                                                              k
                                                                              5 COMMERCIAL STRUCTURES
                                                                                 I

                                                                                 INDICATES NUMBER OF
                                                                                 BUILDINGS

                                                    FIGURE 12
                                 LOWER PATUXENT WATERSHED
            STRUCTURES IMPACTED BY loo YEAR FLOODPLAIN

                                                                                             1\1' @No R T H

                                                                            SIRCE

                                                                XENT

                                                                                    CREE

                                                                                           5

                                                                                           7

                        LEGEND:
                        02- RESIDENTIAL STRUCTURES

                         5 COMMERCIAL STRUCTURES
                       @IkIINDICATES NUMBER OF
                             BUILDINGS

                                                          26

                4.0 References

                1.   Booker Associates, Inc., "Beachcraft Court Stormwater Management

                     Study, Prince George's County, Maryland", WSSC, November 1979.

                2.   Booker Associates, Inc., "Oxon Run Floodplain Study, Prince George's

                     County, Maryland", WSSC, July 1979.

                3.   Clark, Finefrock and Sackett, "Indian Creek Stormwater Management

                     Study, Prince George's County, Maryland", WSSC, December 1979.

                4.   Clark, Finefrock and Sackett, "Weldon Drive Stormwater Management

                     Study, Prince George's County, Maryland", WSSC, August 1979.

                5.   Enviro Plan, Inc., "Environmental Assessment of the Henson Creek

                     Relief Sewer and Stormwater Management Project", WSSC, January 1976.

                6.   Federal Insurance Administration, "Flood Hazard Boundary Maps",

                     Department of Housing and Urban Development, August 1976.

                7.   Gannett, Fleming, Corddry and Carpenter, Inc., "Preliminary Stormwater

                     Management Study at Allison Street-Brentwood on Northwewt Branch,

                     Anacostia River", WSSC, April 1980.

                8.   Greenhorne & O'Mara, Inc., "Cattail Branch Floodplain Study, Prince

                     George's County, Maryland", WSSC, June 1979.

                                                   - 27

               9.   Greenhorne & O'Mara, Inc., "Drum Avenue Drainage Study, Prince

                    George's County, Maryland", WSSC, August 1979.

               10.  Prince George's County Council's Task Force on Flooding, Report dated

                    September 1974.

               11. Prince George's County Stormwater Management Technical Group, "Tinkers

                    Creek Comprehensive Watershed Management Plan", Prince George's

                    County, October 1979.

               12. Prince. George's County Stormwater Management Task Force, "FY 1980

                    Comprehensive Stormwater Management Plan and FY 1980-1985 Capital

                    Improvements Program".

               13. U.S. Army Corps of Engineers, "Review Report on Flood Control and

                    Allied Purposes, Patuxent River and Tributaries, Maryland, February

                    1975.

               14. U.S. Army Corps of Engineers, "Henson Creek Floodplain Information

                    Report", March 1966.

               15.  U.S. Army Corps of Engineers, "Floodplain Information, Piscataway

                    Creek, Prince George's County, Maryland, November 1967.

               16. U.S. Army Corps of Engineers, "Floodplain Information, Beaverdam

                    Creek, Prince George's County, Maryland", September 1967.

                                                 - 28

                 17. Washington Suburban Sanitary Commission Adopted Six Year Capital

                      Improvement Program, Fiscal Years 1982-1987.

       I

                                                    - 29 -

                                     APPENDIX "A"

                              SAMPLE LETTER OF NOTIFICATION

                                               APPENDIX A

                                    Sample Flood Notification Letter
                      This letter of notification was sent to property owners whose
                 homes were found by our analysis to be endangered by the 100 year
                 floodplain. It served to notify the owners of their possible prob-
                 lem and the availability of Federally-subsidized insurance coverage.

                 Dear Property Owner:

                      In-cooperation with the Maryland Water Resources Administration
                 and the Coastal Zone Management Program, the Environmental Planning
                 Division of the Prince George's County Planning Department has initiat-
                 ed an inventory of flooding problems within the County. Information
                 is being gathered which will help the State assess the damage potential
                 and cost of a major flood and plan for necessary relief measures.

                      Due to the scale of maps used and the nature of this survey, some
                 of the properties identified may not actually be flood prone, but
                 based upon a review of existing flood information, it appears that your
                 property may be prone to flooding during a 100-year storm ( a storm with
                 a one percent chance of occurrence in any given year). I would like to
                 emphasize that a conservative approach was taken in identifying flood-
                 prone properties. Any specific information that you can provide based
                 upon your personal observations of flooding in your area will greatly
                 improve the accuracy of our data.

                      I would also like to take this opportunity to inform you of a
                 Federally subsidized flood insurance program that is available to owners
                 of flood-prone properties in Prince George's County. This program,
                 which is administered by the Federal Emergency Management Agency, can
                 provide you with protection from damage.

                      If you have any,questions concerning the Flood Data Inventory
                 Program or wish to provide us with information on flooding, or if you
                 are interested in obtaining flood insurance, please contact the
                 Environmental Planning Division at 952-3651 or 3652. We appreciate
                 your cooperation and assistance.

                                                   Sincerely,

                                                   Dominic J. Motta
                                                   Environmental Planning Division

                 DJM/nlb'

                                                  A-1

                                      APPENDIX "B"

                              HIGHWATER ELEVATION OF SELECTED
                              PRINCE GEORGE'S COUNTY BRIDGES

                                            HIGHWATER ELEVATIONS
                                 SELECTED PRINCE GEORGE'S COUNTY BRIDGES

                                                                         Highwater Elevations
            BRIDGE                     STREAM                      JUNE 21. 1972        SEPT. 22-26, 1975

            Ammendale Rd.             Indian Creek                         -                    127.94

            Bealle Hill Road          Mattawoman                       106.03                   104.12

            Bock Road                 Henson Creek                       75.73                   75.10

            Brinkley Road             Henson Creek                     110.76                   113.79

            Brock Bridge              Patuxent                             -                    116.70

            Gallahan Road             Tinkers Creek                      21.87                   24.00

            Livingston Road           Piscataway Creek                   15.51                   15.64

            Metzerott Road            Paint Branch                         -                     74.05

            Odell Road                Indian Creek                         -                    113.28

            Old Baltimore Pike        Indian Creek                         -                    106.84

            Old Ritchie Road          Southwest Branch                     -                    131.72

            Oxon Hill Road            Henson Creek                         -                     15.93

            Piscataway Road           Piscataway Creek                   22.06                   19.59

            Ritchie Road              Ritchie Branch                       -                    158.65

            Sellman Rd.               Little Paint Branch                  -                    132.06

            Rt. 202 and  408          Western Branch                     21.86                   24.40

            Steed Road                Tinkers Creek                    137.02                      -

            Sunnyside Avenue          Indian Creek                         -                     82.32

            SurrattsRoad              Piscataway Creek                     -                    128.48

            Temple Hill Road          Tinkers Creek                    186.35                   185.67

            Temple Hill Road          Henson Creek                     129.02                   126.31

            Tucker Road               Henson Creek                       71.13                   68-53

            U. S. Rt. 1               Pai,nt Branch                        -                     63.26

            Water Street              Western     Branch                 17.90                   22.08
            White House Road          Southwest Branch                   57.95                   58.35

            NOTE: The information contained in this      appendix was  supplied by the Prince    George's
                   County Department of Public Works     and Transportation
                                                      B-1

                                     APPENDIX "C"

                        SELECTED COMMENTS ON FLOODPRONE PROPERTIES

             APPENDIX 11CH

                                   SELECTED COMMENTS FLOODPRONE PROPERTIES

                                          Anacostia River Watershed

                  Address                                               Comment

             6603 23rd Avenue                                   Hurricane Agnes resulted in 6 ft.
                                                                of basement flooding

             6708 West Park Drive                               Water reached window well during
                                                                Agnes

             6703 25th Avenue                                   Agnes caused 7 feet of basement
                                                                flooding

             4515 34th Street                                   Basement flooding
                                                                Agnes - 8 feet
                                                                David - 3 feet

             4527 34th Street                                   Basement Flooding
                                                                Agnes - 8 feet

             4513 34th Street                                   Frequent basement flooding

             6720 West Park Drive                               Basement Flooding - Agnes

             6609  24th Avenue                                  Basement Flooding - Agnes

             6710  25th Avenue                                  Water surrounded house during Agnes

             6604  24th Place                                   Basement Flooding
                                                                112 feet - Agnes

             6415  24th Place                                   Frequent basement flooding

             5012 Rittenhouse  Street                           Basement Flooding - Agnes

             5004 Rittenhouse  Street                           Basement Flooding - Agnes

             5003 Ravenswood   Place                            Water reached front steps
                                                                during Agnes

             8818 Patricia Court                                Frequent flooding until levee built

             4223 Metzerott Road                                Frequent flooding until levee built

                                                     C-1

             APP ENDIX 11C11                                                                   2

                                      SELECTED COMMENTS FLOODPRONE PROPERTIES

                                              Beaverdam Creek
                    Address                                       Comment

             5203 N. Englewood Drive                        Water has come close to house

                                               Henson Creek

             5410 Stratford Lane                            Frequent flooding until drainage
                                                            improvements were made

             2111 Calhoun Street                            Worst flooding has reached patio

             4304 Weldon Drive                              No flooding has occurred since
                                                            the Temple Hill Road culvert was
                                                            enlarged

             5920 Ladd Road                                 Frequent backyard flooding;
                                                            occasional-basement flooding
                                                            up to 2 feet.

             6413 Roberts Drive                             Frequent property flooding;
                                                            no basement flooding

                                             Piscataway Creek

             7802 Knollwood                                 Basement flooding on 3 occasions
                                                            Agnes, Eloise, Winter 1979

             11753 Crestwood Drive                          Basement fl ooding - Agnes, David;
                                                            maximum 2 feet in basement

             4020 Floral Park Road                          Severe and frequent flooding

                                               Tinkers Creek

             7003 Coolridge Drive                           Basement flooding

                                                    C-2

                                                                                              3
           APPENDIX 11C11

                                  SELECTED COMMENTS FLOODPRONE PROPERTIES

                                            Western Branch

           9103 Sheridan Court                             Frequent yard and basement flooding

           9214 6th Street                                 Frequent basement flooding

           9219 3rd Street                                 Severe flooding; 6 ft. in
                                                           basement 8/31/81

           9111 Wellington Place                           Flood of 8/31/81 came to house

           8811 Magnolia Drive                             Flooded 3 times in 10 years;
                                                           4 feet in basement 8/31/81

           11304 Sherington Court                          House has not flooded; water has
                                                           come close

                                                  C-3

                                      APPENDIX "D"

                            INVENTORY OF FLOODPRONE STRUCTURES

                               I

                                                                                         APPENDIX "DII
                                           LIST OF FLOOD PRO14E AREAS

                   S T R U C T U R E                                                       E L E V A T 1 0 N
                                                                                         lst Floor        100-year
     ---- ----- _TYPE                      -ADDRESS                                      (FT M.S.L.)    (FT M.S.L.

                                            ANACOSTIA RIVER

                                           NORTHWEST BRANCH

         Residential             3400 Allison Street, Brentwood, MD 20722                                    27
                                 3404         If                It                                           If
                                 3406         11                11
                                 3408         11                it
               If                3410         'If
                                 3412         #1
                                 3401         if
                                 3403         11                It
                                 3405         If                if
                                 3407         It
               If                3409
                                 3413
                                 3415         it                                                             If
                                 3417         It
                                 3500
                                 3504                                                                        if
                                 3506
                                 3508
               It                3501         If                11
               it                3503
               if                3505
                                 3507
                                 3600                                                                        It
                                 3602
                                 3604                                                                        it
                                 3606                                                                        11
                                 3603         If                11                                           If
         Residential             2518 Amherst Road, Adelphia, MD 20783                                       65

         Residential             3201 Arundel   Road, Mt. Rainier, MD 20822                                  28
         Residential             2521 Avalon  Place,  Adelphi, MD 20782                                      51

         Residential             3316 Buchanan St.,   Mt. Rainier, MD 20822                                  31
                                 3318-3328  Buchanan  St., Mt. Rainier, MD 20822                             If
                                 3314-3324  Buchanan  St., Mt. Rainier, MD 20822
                                 3331-3337  Buchanan  St., Mt. Rainier, MD    20822

         Residential             3300-3304  Chauncey  Pl., Mt. Rainier, MD    20822                          32
                                 3306-3310      11                 If                                        11
                                 3259-3263      If
                                 3312-3316
                                 3318-3320                         If                                        It
                                 3322-3328                                                                   If
                                 3330-3338
                                                       D-1

                                           L IL S T OF FL 0 0 r; ID-7, A R E A S

                                                                                                         T
                    S T R U C T U R E                                                      P LE V A T 1 0 N
                                                                                         Ist Floor         100-yea
              TYPE                              ADDRESS                                  (FT M.S.L.)           M.S.I.

           Residential                   3200-3214  Chillum Rd., Mt. Rainier, MD 20822                         32
                                         3204-3216                          11 .                               11
                                         3218-3234                          If                                 11
                                         3350-3352
                                         3366-3370
                                         3360-3364
                                         3341-3343                                                             it

           Residential                   2701  Nicholson St., Hyattsville, MD 20782                            32
                                         2703                                                                  If
                                         2705                                                                  it
                                         2707      It
                                         2709      11                  If
                                         2711      It                  11                                      It
                                         2713                          It                                      If
                                         2715                          11                                      11
                 It                      2717      If                  I[
                                         2719      11                  11
                                         2721      It
                                         2723                                                                  it
                                         2725
                                         2727
                                         2729
                 it                      2731      it
                                         2733                                                                  If

           Residential                   31  57-3163  Queens Chapel Rd., Mt. Rainier, MO 20822                 32
                 11                      3117-3121        11                     11                            11
                 If                      3123-3127        11
                 It                      3129-3135        If
                 it                      3145-3149        If
                 If                      3137-3143
                 11                      3220
                 it                      3290

           Residential                   3300-3310 Queenstown Dr., Mt. Rainier, MD 20822                       32
                                         3301-3311                                                             11
                                         3304-3312                                                             it
                                         3305-3313                                                             It
           Residential                   8211 Riggs Rd., Adelphi, MD 20783                                     75
                                         8401      Is           11                                             11
                                         Ran2      it           11                                             11

                                       LIST CF FLOOD PRONE AREAS
                 S T R U C T U R E.                                                   E L E V A T 1 0 N
                                                                                    Is-t. Floor      I 00-yea-,
           TYPE                              ADDRESS                                 FT M. S. L.       M . S
      Residential              2300'Rittenhouse   St., Chillum, MD 20782                                  49
             of                2302
                               2304
                               2306
                               2308
             if                2310
             Is                2312
                               2314                                                                       If
                               2316                                                                       11
                               2318                                                                       Is
                               2320                                                                       IF
                               2322             to               to                                       It
             to                2301             go               it                                       It
             It                2303             If               If                                       I *.
             of                2305                              of                                       to
             If                2307             It               it                                       it
             If                2309             to                                                        It
             91          1     2311             If                                                        11
             it                2313             If                                                        Is
                               2315             It               Is                                       It

      Residential              2301 Sheridin St.,   Chillum, MD    20782                                  51
             Is      .  .      2303             It                                                        If
             If                2305             11      .                                                 11
            .11                2307             Is                                                        to
             It                2309             to
             11                2311             to
             to                2313             to               If
             11                2 315            It               it
             If                2401             11               IF                                       to
             1;                2403             to               If                                       It
      ResIdential              2405 Sheridan St., Chillum, MD.     20782                                51
                               2507             IF               It                                     Is
                               2509             It               of
                               2511             go               Is
             of                2513             oil
             of                2515             of                                                      It
             is                2517             It                                                      It
             as                2519             11               If                                     of
             11                2521             If               Is                                     of
             If                2523             If                                                      to
             it                .2300            If                                                      Is
             11                2302                              If                                     to
             is                2306                              of
             10                2308                              11
             If                2402                              of                                     It
             If                2404                              it                                     go
             to                                 Is               to
                               2408                                                                     so
             to                2410             Is                                                      is

                                                    D-3

                                            LIST OF $'FLOOD PRONE AREAS

                    S T R U C T U R E                                                          E L E V A T 1 0 N
                                                                                            Ist Floor         100-ve
                TYPE                              ADDRESS                                    (FT M.S.L.) (FT M.S.
         Residential               2513  Van Buren    St., Chillum, MD     20782                                  51
                If                 2515               11                11                                        11
                If                 2517               [1                81                                        11
                it                 2519               It                                                          If
                                   2516                                                                           It
                                   2518                                                                           if
                                   2520                                                                           It

         ResidentiaT               @404  Webster St., Brentwood, MD        20722                                  28
                it                 3408               to                11                                        11
                If.                3410               11                it
                :1                 3412               19                11
                                   3401               11                                                          it
                                   3403               If
                                   3407
                                   3409                                 It                                        It
                                   3413                                                                           It

         Residential               6700  West Park    Dr., Chillum, MD     20782                                  65
                11              .  6702          -    11                11                                        11
                it                 6704-                                                                          11
                                   6706                                                                           to
                                   6708               If                If                                        of
                                   6710               is                1.1
                                   6712               If                Is
                if                 6714               It
                                   6716               If
                                   6718               of
                                                      U
                                   6720
         ffesidentia*1'            6802  West Park    Dr., Chillum, MD     20782                                  65
                If                 6804

         Residential               7706  West Park    Dr., Adelphi, MO     20783                                  65
                11                 7708               if                of                                        It
                to                 7710               to
                                   7703               of
                                   7705               it
                                   77-07              If
                                   7711

                                                         D-4

                                          LIST OF FLOOD PRONE AREAS

                  S T R U C T U R E                                                        E L E V A T 1 0 N
                                                                                         Ist Floor         100--yea@
             TYPE                  ---.-,------A-DDRE.SS                                 (FT M.S.L.)     (FT M.S.L.
      Residential               3400  Windom'St.,   Brentwood,  MD 20722                                     27
             it                 3402
             to                 3404
             Is                 3406               If               it                                       to
             11                 3408                                If                                       If
             11                 3410                                it                                       it
                                3403                                                                         If
                                3405               If
                                3407               #1               If
                                3409               If               it                                       if
                                3411                                                                         of
             It                 3413                                                                         It
             if                 3415                                                                         of
             It                 3500                                                                         If

      Residential               2513  Woodberry    St., Adelphi, MD    20783                                 65

      Residential               6603  23rd Ave., Chillum, MD 20782                                           51
             11                 6605                                                                         11
             It                 6607                                                                         Is
                                6609                                If                                       If

      Resident-ial              6602  23rd Place,   Chillum, MD     20782                                    51
                                6604               If               It
                                6606
                                6608
             If                 6601
             at                 6603.                               to                                       If
             Is                 6605               If               is                                       is
             it                 6607               is               of
             1#                 6609                                It
             if                 6611               It               to

                                             AVe.,
    -k-e-s i-d -en-t i a 1      6602  24th         Chillum, MD 2,0782                                        53
                                6604               11               to                                       11
                                660.6              to
      Residenti@]"              6608  24th Ave., Chillum, MD 20782                                           53
             11              .  6610               11               11                                       of
             If                 6612               If               to       -                               If
                                6603               to
                                6605               If
                                6607               If
             Is                 6609               41               If                                       If
                                6611               to               11                                       If
                                6613               Is               It                                       11
                                6615               to               is                                       to
                                6617                                                                         to

                                                       D-5

                                          LIST OF FLOOD PRONE AREAS

                   S T R U C T U R E                                                      E L E V A T 1 0 N
                                                                                       lst Floor        100-ye,.
              TYPE                              ADDRESS                                 (FT M.S.L.) (FT     M.S.1
        Residential              6602 24th Place,   Chillum, MD-    20782                                   51
                                 6604                                                                       it
                                 6606                                                                       It
                                 6608                                                                       If
                                                                    It                                      It
                                 6610
                                 6612              If
                                 6614                                                                       If
                                 6616                               If                                      it
                                 6618
              If                 6620
              If                 6603              It
                                 6605
              if                 6607                               If
                                 6609                               11                                      it
                                 6611                               It                                      to
                                 6613              If               Is                                      to
              Is                 6615              it               If                                      of
              It                 6617                               It                                      of
              It                 6619                               it
              It                 6621              If               It                                      IN
              Is                 6623                               If                                      to
                                 6625

       Residential'              6700 25th Avenue, Chillum,    MD   20782                                   59
                                 6702                               IN                                      It
                                 6704                               If.
                                 6706              If
              at                 67 08.            It               of                                      it
                                 6710
                                 6701              If               If
                                 6703              if
                                                                    it
                                 6705
              It                 6707                               Is                                --------
              11                 6709                               fill                                    it
              It                 6711              at                                                       Is
              It                 6713              11                                                       to
              it                 6715              11               If                                      it

        Residential              4704  31st Pl.,   Mt. Rainier, MD   20822                                 28

                                                       D-6

                                          LIST OF FLOOD PRONE AREAS

                  S T R U C T U R E                                                        E L E V A T 1 0 N
                                                                                          st Floor         100-yeE
            TYPE                                ADDRESS                                  (FT M.S.L.)    (FT _M-S-L

       Residential                       4519  32nd St., Mt. Rainier, MD 20822                             28
                                         4521
                                         4523
                                         4525
                                         4527
           If                            4529                         If
           11                            4531
                                         4518                                                               If
                                         4520
                                         4522
                                         4524
                                         4526
                                         4528                         If
                                         4530                         If

        Residential                      4501  34th St., Brentwood,   MD 20722                             28
                                         4503      11                 11                                    If
                                         4505      If                 If
                                         4507                         11
                                         4509                         If
                                         4511
                                         4513
                                         4515
                                         4523
                                         4527                         If
                                         4529      If
           It                            4528      11
                                         4530
                                         4532
                                         4601
                                         4603
                                         4605

       Residential                       4600  37th St., Brentwood, MD 20722
                                                                                                           27

       Commercial                        5390  Ager Rd., Hyattsville, MD 20782                             32
                                         5620
                                         5950
                                         6000
                                         6002                     If

                                                      D-7

                                           LIST OF FLOOD pqr',.- AR"AS

                    S T R-U    T U R E                                                      E L E V A T 1 0 N
                                                                                          Ist Floor         100-yea
              TYPE                               ADDRESS                                  (FT M.S.L.) (FT M.S.L

          Commercial                       2486-2490 Chillum Rd., Chillum,. MD.20782                         32
                                           2426
                                           2430
              If                           2440
                                           2460
                                           2464                                                                 If
              If                           2490                                                                 it
              If                           2400
              If                           2310-2314
              If                           2222                             It
              if                           2309                             11
              it                           2130                                                                 It.

          Commercial                       1901  Hamilton St., Hyattsville, MD 20822                         32
              11                           2001      11                  11                                     it
                                           2781
                                           2801

          Commercial                       3171-3191 Queens Chapel Rd., Mt. Rainier, MD 20822                32.
                                           3100-3130

        Commercial                         2500-2520  University Blvd., Adelphi, MD 20783                    65
                                           2400-2426          11              11
                                           2501               If
                                           2503
                                           2505                                                                 If
                                           2507                                                                 11
                                           2509
                                           2511

                                                        D-8

                                             LIST OF FLOOD PRONE AREAS

                                     S T R U C T U R E                                         E L E V A T 1 0 N
                                                                                           lst Floor         100 year
                TYPE                               ADDRESS                                 (FT M.S.L.)      (FT_M.S.L

                                                     SLIGO  CREEK

          Residential              2001  Oglethorpe St., Chillum,    MD 20782                                  46
                                   2003
                                   2000
                                   2002

          Residential              1903  Oliver  St., Chillum, MD    20782                                     46
                                   1905
                                   1907
                                   1909
                                   1911                                                                         If
                                   1913
                                   1915
                                   2003
                                   2005
                                   2007                                                                         If
                                   2009
                                   2002                            If
                                   2004
                                   2006
                                   2008

          Residential              2001  Peabody St., Chillum, MD      20782                                    46
                                   2003          it
                                   2005
                                   2007
                                   2000
                it                 2002          it                It                                           It
                11                 2004                            11                                           11
                If                 2006                            If
                11                 2008                            11

          Residential              2003  Powhattan Rd., Chillum, MD 20782                                       46
                                   2005          It                11                                           it
                                   2007          It
                                   2000
                                   2002
                                   2004          If                                                             to
                If                 1901          11                                                             it
                It                 1903          it
                11                 1905
                It                 1907
                11                 1909                                                                         It
                It                 1902
                11                 1904                            it

          Residential              2001  Rittenhouse St., Chillum,    MD 20782                                  52
                                   2003                                                                         If

                                                        D-9

                                                   LIST OF FLOOD PRONE AREAS
                                          S T R U C T U R E                                             E L E V A T 1 0 N
                                                                                                   lst  Floor         100 yeai
                   TYPE                                  ADDRESS                                   (FT  M.S.L.)       (FT M.S

             kes-i dential'            2005   Rittenhouse   St., Chillum, MD 20782                                      52
                                       2007                                                                             11
                                       2009
                                       2011
                                       2000
                                       2002
                                       2006
                  If                   2010
                  It                   2012                                  If

            Residential                2007  Roanoke St., Chillum, MD        20782
                                                                                                                        52
                                       2009
                                       2011
                                       2013
                  If                   2000                                  If
                                       2002                                  11
                                       2004                                  It
                                       2006                                  If
                                       2008
                                       2010
                                       2012
                                       2014
                                       1900
                                       1902                                  If.

            Residential                6021  Sligo Parkway, Chillum, MD         20782                                   46
                                       6023               it                 11                                         it
                                       6025               it
                                       6027
                                       6029                                                                             It
                                       6103
                                       6105               it
                  it                   6107               11
                                       6201               If
                                       6203
                  it                   6205
                  If                   6207                                                                             it
                                                                             If
                                       6209
                                       6211
                                       Ul 3.
                                       6215
                                       6217
                  it                   6219
                                       6221                                  If
                                       6223               If
                                       6225                                  it
                                       6227
                                       6229

                                                              D-lo

                                                LIST OF FLOOD PRONE AREAS
                                       S T R U C T U R E                                             E L E V A T 1 0 N
                                                                                                lst Floor          100 year
                 TYPE                                 ADDRESS                                   (FT M.S.L.)        (FT M.S-@

          Resi:dent.fal              6231  Sligo Parkway, Chillum,      MD 20782                                     46
                                     6233             11               11                                             11
                                     6303                                                                            52
                                     6305                                                                             11
                                     6307
                                     6309
                                     6311
                                     6313
                 If                  6315
                 If                  6317
                                     6319
                 If                  6321
                                     6323
                                     6403
                                     6405                                                                             If
                 If                  6407
                                     6409
                                     6411
                                     6413
                                     6415
                                     6417
                                     6501                                                                            59
                                     6503
                                     6505
                                     6507
                                     6509
                                     6511
          Residentiai                2000  Somerset   St., Chillu   m, MD 20782                                      52
                 It                  2002                                                                             11
                                     2004                                                                             If
                                     2006
                                     2001
                                     2003
                                     2005
                 If                  2007

          Residential                2000  Tucke  rman St.,.Chillum,    MD   20782                                   59
                                     2002             If
                                     2004.            11
                                     2006                                                                             If
                                     2001
                                     2003
                                     2005
                                     2007                                                                             it

          Residential                6020  20th Ave.,    Chillum,    MD 20782                                        46
                 to                  6022             11               11                                             If
                 It                  6024             If               it

                                                            D-11

                                                LIST OF FLOOD PRONE AREAS*
                                       S T R U C T U R E                                          E L E V A T 1 0 N
                                                                                              lst Floor         100 year
                  TYPE                                 ADDRESS                                (FT M.S.L.)       (FT M.S.

           Residential               6102  20th Ave.,    Chillum,  MD 20782                                       46
                                     6104
                                     6106
                                     6200
                                     6202
                                     6204
                                     6206
                                     6212
                                     6214
                                     6216              If        It
                                     .6218             If
                                     6220
                                     6222
                  it                 6224
                                     6226
                                     6228
                                     6230                                                                         If
                  it                 6302              if        It
                  11                 6304              It        It
                  If                 6306
                                     6308
                                     6310                                                                         It
                                     6312                                                                         11
                                     6021                                                                         If
                                     6023                        it                                               It
                                     6025                        11                                               11
                                     6027                        If                                               it
                                     6103
                                     6201
                                     6203
                                     6207
                                     6209              If
                                     6211
                                     6213
                  it                 6215
                                     6217
                                     -6219
                                     6221                                                                         If
                                     6223
                                                                                                                  it
                                     6225
                                     6227
                                     6314                                                                         52
                                     6316                                                                         It
                                     6318
                                     6320                        If
                                     6322              If        IV:
                                     6402
                  It                 6404

                                                          D-12

                                            LIST OF FLOOD PRONE AREAS'
                                    S T R U'C T U R E                                        E L E V A T 1 0 N
                                                                                         lst Floor        100 year
               TYPE                               ADDRESS                                (FT M.S.L.)      (FT M.SJ

         Res-id'entfal            6406  20th Ave., Chillum, MD 20782                                        52
                                  6408
                                  6410
                                  6412
                                  6414                                                                      If
                                  6500                                                                      59
                                  6502
                                  6504
               If                 6506
                                  6508
                                  6510

         Residential              6200  20th Place, Chillum, MD 20782                                       46
                                  6202                      11
                                  6204                      If
                                  6206
                                  6208
                                  6210
                                  6212
                                  6214
                                  6216
                                  6218                      If
                                  6220                      If
                                  6224
                                  6226
                                  6228
                                  6201
                                  6203
                                  6205
                                  6207          If          11
                                  6209         If                                                           it
                                  6307                                                                      59
                                  6315                                                                      of
                                  6403
                                  6409
                                  6503
               it                 -65b5
               If                 6507

                                                     D-13

                                             LIST OF FLOOD PRONE AREAS

                     S T R U C T U R E                                                       E L E V A T 1 0 N
                                                                                           lst Floor        100-yeai,
               TYPE                               ADDRESS                                  (FT M.S.L.) (FT M.S.L.

           .-Residential                     2000  Sheridan St., Chillum, MD 20782                             52-
                  If                         2002      1)
                                             2004
                                             2006
                                             2001
                                             2003
                                             2005
                                             2007      it               it

            Residential                      2000 Ravenswood St., Chillum, MD 20782                            52
                                             2002      At
                  it                         2004      If
                  11                         2006
                  If                         2001
                                             2003
                                             2005

                                                         D-14

                                             LIST OF FLOOD PRONE AREAS

                                     S T R U C T U R E                                         E L E V A T 1 0 N
                                                                                             lst Floor       100 year
                 TYPE                              ADDRESS                                  (FT M.S.L.)     (FT-Ki-_S.L

                                                  NORTH EAST BRANCH

          Residential              4908  East-West Hwy., Riverdale, MD 20840                                   29

          Residential              5309  Greenway Dr., Edmonston, MD 20781                                     21
                 11                5311              11          11                                            11

          Residential              5311  Patterson   Rd., Riverdale, MD 20840                                  29
                 If                5313                          11
                 11                5315
                 If                5317
                                   5312                                                                        If
                                   5314
                                   5316
                                   5318
                                   5320

          Residential              5301  Powhatan St., Riverdale, MD 20840                                     29
                                   5303              11          11                                            If
                                   5305              11          If
                                   5307
                                   5311
                                   5313

          Residential              5414  Quesada Rd., Riverdale, MD 20840                                      29
                 11                5422              11          11                                            11

          Residential              5301  Quintana St., Riverdale, MD 20840                                     29
                                   5303                                                                        If
                                   5305                                                                        11
                                   5302                                                                        If

          Residential              4909  Ravenswood Rd., Riverdale, MD 20840                                   29
                 If                4911                          of                                            11
                                   4913                                                                        If
                                   5003                                                                        11
                                   5005                          If
                                   5007
                                   5009                                                                        If
                                   5011                                                                        11
                                   5004
                                   5006
                                   5008
                 If                5010
                 11                5012

          Residential              5000  Rittenhouse   St., Riverdale, MD 20840                                29
                 11                5002              11          11                                            11
                                   5004
                                   5006

                                                        D-15

                                               LIST OF FLOOD PRONE AREAS
                                       S T R U'C T U R E                                          E L E V A T 1 0 N
                                                                                             lst Floor         100 yeai
                 TYPE                                ADDRESS                                 (FT M.S.L.)       (FT M.S

           Re,sidential*            5008  Rittenhouse St., Riverdale, MD 20840                                  29
                                    5012

           Residential              5306  Riverdale   Rd., Riverdale, MD 20840                                  25
                 If                 5308             It           11
                                    5312                          it
                                    5314
                                    5316
                                    5318
                                    5320                                                                        it
                                    5322
                                    5324

           Residential              5006  Sheridan   St., Riverdale, MD 20840                                   31
                                    5008                                                                        11
                                    5010
                                    5012
                                    5005
                                    5007             It
                 it                 5009             It
                                    5011
                                    5013                                                                        It

           Residential              5005  Somerset Rd., Riverdale,     MD 20840                                 31
                 1)                 5007
                 11                 5009

           Residential              6303  Taylor Rd., Riverdale, MD       20840                                 29
                                    6305             11                                                         11
                                    6311
                                    6313
                                    6315                                                                        If
                                    6317                          If

           Residential              5007  Tuckerman   St., Riverdale, MD 20840                                  33
                                    5011
                                    5013
                                    5015
                                    5017
                                    5012
                                    5014
                                    5016             If           it.
                                    5018                          If
                                    5020                          11                                            If
           Residential              6120  54th Ave., Riverdale,     MD  20840                                   25
                 11                 6122             11.          11                                            11
                                    6124
                                    6126
                                    6200
                                    6202
                                    6204

                                                          D-16

                                     LIST O.FFLOCD PRONE AREAS

                 S T R U C T U R E                                             E L E V A T 1 0 N
                                                                             Ist Floor       100-y-ar
            TYPE                          ADDRESS                             (FT M.S.L.) (FT M.S.L.

        Commercial                 6250-6270 Kenilworth Ave., Riverdale, MD 20737              31
                                   6300             11              11
                                   6322-6324
                                   6328
                                   6408             It              11                          it
                                   6410                                                         11
                                   6504                                                        33
                                   6510                                                         11
                                   6600                                                         It
            It                     6715                                                         It
                                   6801                                                         It

                                                D-17

                                              LIST OF FLOOD PRONE AREAS

                                       S T R U C T U R E                                        E L E V A T 1 0 N
                                                                                             Ist Floor       100 yeav
                  TYPE                              ADDRESS                          -      (FT M.S.L.)     (FT M.S.L

                                                        INDIAN CREEK

           Residential              5101  Cleveland Ave., College Park, MD 20740                                52
                  If                5402                11             11                                       11
                                    5500
                                    5502
                                    5519

           Residential              4906-Navahoe St.,    College Park,   MD 20740                               60
                                    4910                                                                        11
                                    5009@                                                                       58
                                    5011                                                                        It
                                    5013
                                    5101
                  If                5103
                  11                5105
                  If                5107
                  11                5109
                  If                5004
                  11                5010
                  If                5014                If
                  it                5100                11
                                    5106
                                    5108
                                    5110
                                    5112                                                                        it
                                    5114                                                                        11
                                    5116                                                                        it
                                    5118                If
                                    5120                11
                                    5122                it                                                      it
                                    5124                If                                                      If
                                    5126                It                                                      11

           Residential              2000  Ravenswood    St., Chillum,  MD 20782                                 52
                                    2002                               to
                                    2004                               it
                                    2006
                                    2001                If-
                                    2003
                                    2005                of             It

           Residential              5500  Richmond Ave., College Park, MD 20740                                 50

           Residential              2000  Sheridan St., Chillum, MD 20782                                       52
                                    2002
                                    2004

                                                          D-18

                                              LIST OF FLOOD PRONE AREAS
                                     S T R U C T U R E                                              E L E V A T 1 0 N
                                                                                               lst Floor          100 year
          ---TYPE                                   ADDRESS                                    (FT M.S.L.)        (FT M.S.

        R-esfdential               2006  Sheridan   St., Chillum, MD. 20782                                         52
                                   2001
                                   2003
                                   2005
                                   2007            If            It

        Residential                8000  51st Ave., College Park, MD '20740                                         65
                                   8002            If            if                                                    if
                                   8006                                                                                If
                                   8001                                                                                Ob
                                   8003                          If                                                    It
              It                   8012                                                                                ic
              Is                   8108                                                                                of
              It                   8105                                                                                cc
                                   8.111                                                                               If
                                   8113
                                   8115                                                                                It
                                   8117                          If

        Residential                8002  54th Ave., College Park, MD          20740                                 64
              it                   8004            11            11                                                    If
                                   8006            11            It                                                    it
                                   8008            If            of                                                    it

        Commercial                 5502  Albany    Ave., College Park, MD 20740                                     52
                                   5504            11            11                                                    11
                                   5507                          It

        Commercial                 5503  Atlanta Ave., College Park, MD 20740                                       52
              If                   5505            It            If

        Commercial                 5107  Berwyn    Rd., College   Park, MD 20740                                    54
                                   5111            11            If                                                    DO
                                   5113            it            Is                                                    ED
                                   5119                          Is'                                                   at
                                   51-13                         is                                                    It
                                   5115                          Is                                                    If
                                   5117                          If

        Commercial                 4905  Navahoe   St., College    Park, MD 20740                                   60
              if                                   11            If
                                   5134                                                                             58

        Commercial                 8100  Rhode   Island Ave., College Park, MD          20,740                      58

        Commercial                 8005  51st Ave., College-Park, MD 20740                                          65

        Commercial                 8300  54th Ave., College.Park, MD 20740                                          65

                                                            D-19

                                            -LIST OP FLOOD .'PRONE AREAS
                     STRUCTURE                                                                  ELEVATION
                                                                                            Ist Floor         100-yeai
                TYPE                               ADDRESS                                   (FT M.S.L.) (FT M-SA

                                               PAINT BRANCH

             Residential              9002  Bote'ler Lane, College Park, MD 20740                                 78
                                      9006       If                                                                 11
                                      9007       it                                                                 If
                                      9041

             Residential              4800  Lakeland Rd., College Park, MD 20740                                  58
                                      4802                                11                                        11
                                      4808                                it
                                      4812
                                      4900
                                      4902
                                      5002                                                                        60
                                      5004
                                      5008
                                      5013
                                      5014                                it
                                      5015
                                      5016
                                      5019       It
                                      5021
                                      5022                                                                          If
                    If                5100       it                                                               64
                                      5102       11                                                                 11
                                      5103       If
                                      5104       It                       It
                                      5108                                                                          it
                                      5109
                                      5110
                                      5111

             Residential              4101  Metzerott Rd., College Park, MD 20740                                 75
                                      4103
                                      4105
                                      4109
                    If                4201       11
                    11                4203       it                       If
                    It                4221
                                      4223

             Residential              8802  Patricia  Court, College Park, MD 20740                               75
                    If                8804       11
                                      8806
                                      8808
                    If                8810       11
                    It                8812                                If                                        It

                                                          D-20

                                             LIST OF FLOOD PRONE AREAS.

                    S T R U C T U R E                                                            E L E V A T 1 0 N
                                                                                               lst Floor         100-year
               YPE                                 ADDRESS                                     (FT M.S.L.)     (F-r M-,-S. L..

                                              PAINT BRANCH

           Residential                8814  Patricia Court, College Park, MD 20740                                   75
                                      8816
                                      8818
                                      8803
                 If                   8805       11
                                      8807
                                      -8809
                                      8811                                 If
                                      8813
                                      8815
                                      8817
                                      8819       If

           Residential                8000  Travis Lane, College Park,      MD 20740                                 75
                                      8002       If
                                      8004
                                      8001
                                      8003
                                      8005  .    If                        of                                          It
                                      8007       If

           Commercial                 4902  Calvert Rd., Riverdale, MD      20737                                    46
                 11                   4917-4923 Calvert Rd., Riverdale, MD 20737                                       11

           Commercial                 4911-4917 College Ave., College Park, MD 20740                                 46
                 11 .                 5001                                 If
                                      5003
                                      5005
                 If                   5012             If

           Commercial                 1303  Cpl.  Frank  Scotts Dr., College Park, MD 20740                          52
                                      6707

           Commercial                 4915  Lehigh Rd., College Park, MD 20740                                       46
                                      5008                         If
                                      5012
                                      4908-4914

                                      3838  University Blvd., College Park, MD 20740                                 78
           Commercial                 4925   50th Ave., College Park, MD 20740                                       52
                 11                   7410
                 If                   7415

           Commercial                 5018  Lakeland Rd., College Park, MD 20740                                     60
                                                           D-21

                                            LIST OF FI-C00 PRONE JAREAS
                                                                                             E L E V A T 1 0 N
                                    S,T R U C T U R E                                   Ist Floor         100 YE
               TYPE                               ADDRESS                               (FT  M.S.L.)       FT M.

                                                    BEAVER  DAM

         Residential              2400 Beaver Road, Kent   Village, MD 20785                               41
               11                 2130                        If                                             11
               of                 2120

         Residential              6401 Country   Club Court,  Kent Village, MD    20785                    54
               Is                 6403           11           #1                                             it
               it                 6400           If           11                                             is
                                  6405                        it                                             11
                                  .6402

         Residential              2707 Country   Club Rd., Kent Village, MD 20785                          54
               If                 2715                                                                       if
                                  2717                                                                       41
                                  2723                                                                       is
                                  2727                                                                       If
               If                 2701                                                                       11

         Residential              1600 Englewood   Ave., Cheverly, MD      20785                           31
               If                 1602           it           It                                             11
               11                 1604           11           11                                             11
               11                 1603                                                                       11
               11                 1605                                                                       if

         Residential              2708 Hawthorne   Terrace,   Kentland, MD 20785                           53
                                  2710           91           11                                             If
                                  2712                                                                       It
                                  2714                                                                       Is
                                                 If           19                                             if
                                  2716
                                  2718
                                  2720
               at                 2722           If           If                                             to

         Residential              5314 N. Englewood Dr., 'Cheverly,    MD  20785                           33
               If                 5210           to           of                                           32
               91                 5212
                                  5214           If
               It                 521.6          11           If                                             If
               It                 5218           It           If
               It                 5201-          Is           11
                                  5203           11           of                                             to
               It                                             It                                             it
                                  5205
               it                                11           If
                                  5300                                                                     33
                                  -i'302         It           it                                             it
                                                 It                                                          it
                                  5304
                                  5306                        to                                             19
               If                 5207           11           11                                           32
                                  5108           It           11                                             11
                                                                                                             It
                                                 Is           It

                                                       D-22

                                          LIST OF FLOOD PRONE AREAS

                   S T R U C T U R E                                                       E L E V A T 1 0 N
                                                                                         lst Floor         100-yea
              TYPE                              ADDRESS                                  (FT M.S.L.)     (FT M. S. L
       R@sid'entia'f             2600 Pinebrook Ave., Kentland,.MD                                           54
              11                 2602           Is          Is                                                 It
              it                 2604                       It                                                 so
              11                 2606                                                                          to
                                 2608
              13                 2610           it

       Residential               1810 61st  Ave.,  Cheverly, MD 20785                                        35
                                 1812           11          11                                                 11
                                 1814           11          It                                                 of
                                 1817           to                                                             to
                                 1815           It
                                 1813           It
                                 1808           11
                                 1811           Is

       Residential               1814 62nd Ave., Cheverly, MD 20785                                          .37
                                 1812
                                 1810                       Is
                                 1815
                                 1813
                                 1811
                                 1808
              If                                            it                                                 it
                                 1809

       Commercial                8121 Ardwick Ardmore, Rd., Ardwick Industrial Park                          75
                                 8201

       Commercial                5800 Columbii   Park Rd., Cheverly, MD 20785                                41
              if                 5801                                                                          14
              it                 5720                                                                        40
              Is                 5718                                                                          If
              of                 5716                                                                          11
        Commercial               5700 Columbia  Park Rd.,   Cheverly, MD 20785                               35
              It                 5620         11                   11                                          it
                                 5618         11                   is                                          If
                                 5610                              If
                                 5600                              11
                                 5701

       Commercial                7229 Country   Club Rd.,   Kentland,  MD 207805                             54
              11                 7233           11          If                                                 to
              16                 7241           It          to                                                 it
              It                 72-243         to          is                                                 it
              of             .   7245           .16         It                                                 it
                                 72491.         It
                                     i
                                 7301

                                                        D-23

                                          LIST OF FLOOD PRONE AREAS

                   S T R U C T U R E                                                      E L E V A T 1 0 N
                                                                                       lst Floor        1 00-ye-;:
              TYPE                              ADDRESS                                (FT M.S.L.)    (FT M.S.!

                                                                                                           15
        %lomr-nercial            6900 Old Landover Rd., Kentland, MD 20785
                                 6907         If .         11
                                 6911         It           it
                                 7000         to           11
                                 7100         If

        Comme rc i al            3101 Pennsy  Dr. , Kentland, MD 20785                                     53
                                 3120                                                                        it
                                 3133
            If                   3137                      If
            it                   3301          It          is
                                 3300          it          It

                                                       D-24

                                        LIST OF FLOOD PRONE AREAS
                                 Sj R U*C T U R E                                       E L E V A T 1 0 N
                                                                                   Ist Floor        100 yeai
            TYP E                             -AD-P-RESS - -- ------               (FT M.S.L.) -JFT M.S,

                                                  OXON RUN

         Residential            507 Drum Ave., Capitol Heights, MD 20027              140            140
                                509                                                   ljq            142
                                511                                                   142            142

         Residential            2430 Green Valley  Dr., Suitland, MD 20023                           153
                                2428                                                                 155
                                2426                                                                 157
                                2424
                                2422                                                                 154
                                .2420

                                            LIST-01c' FLOOC PRONE AREAS
                                    S T R U C T U R E                                        E L E V A T 1 0 N
                                                                                        Ist  Floor       100 ye@
               TYPE                               ADDRESS                               (FT M.S.L.)      (FT M.!

                                                  HENSON CREEK

         Residential             4004  Beachcraft Ct., Temple    Hills, MD 20031                           160
               11                4006             It             it                                          U
               if                4008                            If                                          91
               Is                4012                                                                        if
               11                4010                                                                        Is
               Is                4003
               If                4005             11.1
         Residential             7102  Bock Rd.,  Oxon Hill 20022                                            81
                                 7104                            If
         Residential             3701  Brinkley   Rd., Temple Hills, MD 20031                              121
               If                3504             It             11                                          it
               Is                3500             Is                                                         It

         Residential             2103  Calhoun St., Oxon Hill, MD 20022.                                     82
               If                2105             Is             It
               11                2107
               It                2109
                                 2111
                                 2113
                                 2201                            If
                                 2203                            11
                                 2205                            It                                          if
               If                2207                            it
                                 2209             of             to
               It                2211                            it                                          to
                                 2213                            it
               it                2215                            Is                                          it
               It                2301                            It                                          If
               11                2303             Is             11                                          11
               If                2305             It             11                                          if
               at                2307             It             it                                          11
               If                2309                            11                                          It
                                 2311                            If                                          to

         Residential             4304  Canterbury Way-House, Temple Hills, MD 20031                        134
         Residential             4609  Eaton Dr.,  Marlow Heights, MD 20023                                171
                                 4611                            If                                          it
                                 4614             It             It
               If                4612
               11                4610
               19                4608             It

         Residential             4001  Forest Grove Dr., Suitland, MD 20023                                199
                                 4005

                                                      D-26

                                              LIST OF FLOOD PRONE AREAS

                    S T R U C T U R E                                                           E L E V A T 1 0 N
                                                                                              lst Floor         100-ye
              TYPE                                 ADDRESS                                    (FT M.S.L.) (Fr M.S.

    -sidenti'al              4310 Hartlor
                                        I d Hills, Suitland, MD 20023-                                      195
                             4308             11              11                                              Is
                             4306

    asidential               4206  Henderson   Rd., Temple Hills, MD       20031                            195
        is                   4300             11              If                                              11
        Is                   4302             If
    !sidential               5400  Henson Dr.,    Temple Hills, MD 20031                                    195
    @sidential               7903  Indian Head   Highway, Oxon Hill, MD 20745                               N/A
                             7907              11
                             7911              it
    !sidential               .8420 Indian Head    Hwy., Oxon   Hill,  MD 20022                                28
                             8422             If              11
                             8424                             If
                             8426                             11
        If                   8428             If              Is
        of                   8430             Is              It
        if                   8432             to              10
        it                   8434
    !sidential               5813  Keppler    Rd., Temple Hills, MD 20031                                   158
                             5817             11              Is
                             5814             If              to
                             5808             11              to
                             5806             If
                             5811
        If                   5807                             If                                              Is
                             5805                             It
                             5803                             18
                             5801             If              if
                             5719             If              of
                             5717             11              It                                              11
                             5715             is
        If                   5713             If
        11                   5711             of                                                              If
        If                   5709
        to                   *5707
        of-                  -5705
        If                   5703
        Is                   5701
        it                   5519
        It                   560i
                             5607
                             5605
                             5603

                                                           D-27

                                           LIST OF FLOOD PRONE AREAS

                   .S T R U C T U R E                                                      E L E V A T 1 0 N
                                                                                        Ist Floor         100-ye
              TYPE                               ADDRESS                                 (FT M.S.L.) (FT M.@z_
    Residential               5920 Ladd Rd.,   Suitland    MD  20023                                    160
                              6003          11              is                                           it
                              6005          it              If                                           11
                              6007          11             if'                                           11
                              6009          to
                              6011
                                                                                                         If
    ResIdential               5922 Ladd Rd., Suitland, MD       20023                                   160
                              6000                                                                       of
                              6002
                              6004
                              6006         11           If                                               is
                              6008         It  -
                              6010         Is
                              6012         11           If
                              6014         If           11                                               It
                              6016         11           if      I                                        If
           of                 6018         Is           If                                               to
    Residential               9101 Livingston Rd., Oxon Hill,      MD  20022                             28

    Residential               4901 Meadowbrook Dr., Suitland,      MD  20023                            175
                              4902         If           19                                               If

    Residential               4101 Offut Dr., Suitland, MD 20023                                        175
           If                 4103         11           it                                               of
                              4100         Is           It

    Residential               5402 Old Temple Hill Rd., Temple Hills, MD 20031                          125
           If                 5400         If           Is                                               It
           of                 5413
                              5411                                                                       of
                              5409
                              5600
           to                 4356         If           If                                               of

    Residential               902 Palmer Rd., Oxon Hill, MD 20022                                        35

    Residential               6415 Roberts Dr., Temple Hills, MD 20031                                  121
                              6413                                                                       If
                              6409                                                                       Is
                              6405         if           11
                              .6411        to           11
                              6407         It        .  It *
           If                 6403                      if

    Residential               5410 Strafford Lane,     Temple Hills, MD 20031                           158
                              5408
                              5406                      If                                               It
           to                 5404
           11                 5402
           is                 5400
           is                 5312
           Is                 5310         to           Is

                                             LIST OF FLOOD PRONE AREAS

                   S T R U C T U R E                                                              E L E V A T 1 0 N
                                                                                                lst Floor          100-yea
              TYPE                                 ADDRESS                                      (FT M. S. L.      FT    S. L

      Risid6ntidl'                6206  Suitland Rd., Suitland, MD 20023                                             195
              If                  6208

      Residential                 5515  Temple Hills Rd.,        Temple Hills, MD 20031                              134
              to                  5601            Is             11
              It                  5603            111,           If
              01                  5607
              It                  5410
              it                  5412

      Residential                 4300  Weldon    Dr., Temple    Hills, MD 20031                                     153
              to                  4302                           11                                                     to
              If                  4304                                                                                  It
              to                  4306                                                                                  to
              It                  4308            to                                                                    it
              is                  4310            Is             If                                                     It
              19                                  If             Is                                                     11
                                  4312
              It                  4314            If             It                                                     It
                                  4316            it             It

       Residential                501-507  Wilson   Bridge Dr.*,   Oxon  Hill, MD   20745
              It                  509-515
              11                  517-523
              It                  525-531                                                                              It
                                  533-539
                                  541-547
                                  549-555                                  It                                          It
              it                  557-563                                  11
              11                  565-573

                                                            D-29

                                           LIST OF FLOOD PRONE AREAS

                    S T R U C T U R E                                                     E L E V A T 1 0 N
                                                                                        lst Floor        100-ye
              TYPE                              ADDRESS                                 (FT M.S.L.) (FT_M.S.

       Residential              6211   Woodland Rd., Suitland, MD 20023                                    175
              it                6301          11            11
                                6303          of
                                6305          to
                                6307          It
                                6311-                       It                                               it
                                6401                        It
                                6405                        11
              it                6409          It            If                                               If
              If                6411          It
              If                6415          It
              of                6417          11                                                             It
                                6419          It            It                                               it
                                6501          It            It                                               It
              It                6505          to            It                                               It
              If                6509          It            It                                               It
              It                651  5                                                                       11
                                                                                                             if
                                6517
                                6519                                                                         #1
                                6600.
                                6602
                                6604                                                                         if
                                6606
              It                6608                        It                                               If
              to                6610                        it                                               it
              11                6612          It            It                                               if
                                6614          It            of                                               it
                                              It                                                             If
                                6616
                                6618          Is                                                             If
              it                6620          Is                                                             1,
                                6622'         It
                                6700          it

                                                        D-30

                                          LIST O= FLOOD PRONE AREAS
                                                                                           E L E V A T 1 0 N
                                  S T R U'C T U R E                                   1st  Floor        100 yea@
              -T-YPE                            ADDRESS                               (FT  M.S.L.)_     (FT M.S.

                                8500 Indian Head Hwy.,   Oxon Hill, MD    20022                           28

       Commercial               9100 Livingston Rd., Oxon Hill, MD 20022                                  28
                                9116                           If                                         Is
                                9011                           of
                                9001                           If

       Commercial               5007 Meadowbrook   Dr., Suitland, MD 20023                                175

       Commercial               4625 Old-Branch Ave., Temple Hills, MD 200311                             171
            if                  4600

       Commercial               6101 Suitland Rd., Suitland-1.  MD 20023                                  195
                                6200

       Commercial               709 Taylor Acres Ave., Oxon    Hill, MD 20022                             18

                                                    D-31

                                          LIST OF FLOC)D PRONIE.' AREAS
                                   S T R U C T U R E                                     ELEVATIOIN
                                                                                    Ist  Floor        100 V e a
               TYPE                             ADDRESS                              (FT M.S.L.)          Vi @
                                                                                                      (FT

                                                 TINKERS CREEK

         Residential             6901 Coolridge Dr., Suitla.nd, MD 20031
               11                6907         11 .         of
                                 7007         It           It
                                 7003         It           It

         Commercial              6709 Branch  Ave., Suit-land, MD   20031
               It                -6711        It           It                                            It

                                                                                                         of
         Commercial              6805 Coolridge Dr., Suitland, MD 20031
               11                6807         11
               it                6809                                                                    at

                                 6813         It
               it                6815         Is           It
               It                6817         at

                                                     D-32

                                           LTS'r OF FLOOLD, PRONIE ArEAS
                                               I

                   S T R U C T U R E                                                        E- L E V A T 1 0 N
                                                                                          lst Floor         100. ycar
             TYPE                                ADDRESS                                  (FT M.S.L.)    LF, ji_-M . S-,..L .

                                               PISCATAWAY

         Residential                    11729  Crestwood Ave., North Clinton, MD 20613                        110
                                        11737
                                        11741
                                        11745      If                    it
               If                       11749      It
                                        11753                                                                   If

         Residential                    3006 Floral Park Rd., Clinton,     MD 20613                            34
                                        3106
                                        3402
                                        3410       If.
                                        3500
                                        3611
                                        3701                                                                    If
                                        3708                                                                    11
                                        3710                             If
                                        3711                             11
               If                       3805       11                    11
                                        3806
                                        4001
                                        4006
                                        4020

          Residential                   7800 Knollwood St., Brandyviine, MD 20613                             110
               If                       7802       11
               11                       7803       11
                                        7804                             If
                                        7805                             11                                     If
               it                       7806       If
               11                       7807       11
               If                       7808       11
               11                       7809       11                    It                                     It
               it                       7810       If                                                           it
               If                       7811       11                                                           11
                                        7812
                                        7813
                                        7815       If
               It                       7901       If                                                           It

          Residential                   13512 Livingston Rd., Accokeek, MD 20022                               17
                                        13514      it                                                           U
                                        13515                                                                   If

                                                        D-33

                                                LIST OF FLOOD PRONE AREAS

                     S T R U C T U R E                                                            E V A T 1 0 N
                                                                                           lst Floor        100-year
                TYPE                              ADDRESS                                  (FT M.S.L.) (FT M.S.L.

                                                PISCATAWAY (cont'd)

           Residential                   13516  Livingston  Rd., Accokeek, MD 20022                             17
                                         13600     11
                                         13604     It
                                         13606
                                         13711
                                         13712
                                         13801
                                         13809                            It
                                         14001

                                         13401  Piscataway Rd., Clinton,    MD 20613                            34

                                         7600   Redwood Ct., Brandywine, MD 20613                              118
                                         7601                                                                    if
                                         7602
                                         7603
                                         -7604
                                         7605
                                         7606

           Residential                   11708  Redwood Dr.,.Brandywine,   MD 20613                            118
                                         11712
                                         11713
                It                       11716     11
                11                       11717     It
                It                       11720     it
                It                       11721     If                                                            It
                                         11724
                It                       11725     it
                                         11728
                                         11729
                                         11733
                                         11801

          Residential                    3604 Taylor Circle, Ft. Washington, MD 20022                           18
                                         13001 Winebrook Dr., Clinton, MD 20735                                .44

          Commercial                     11700 Brandywine Rd., Clinton, MD 20613                               94

                                                        D-34

                                          LIST OF FLOODIRON'E AREAS
                   S -1 R U C T U R E                                                     E L E V A T 1 0 N
                                                                                        Ist Floor        100-year
             TYPE                               ADDRESS                                 (FT M.S.L.)     FT M..S.L.

                                               PATUXENT

          Residential                17001 Annapolis Rd., Annapolis, Md. 20715                               43

          Residential                26 Avondale St., Laurel, Md. 20811                                    148

          Residential                12921 Brock Bridge Rd., Laurel,    MD 20811                           116
                                     12923
                                     12925             If
                                     12927
                                     12929
                                     12931
                                     12909
                                     12911
                                     12913
               If                    12915
                                     12917
                                     12919
                                     12901
                                     12903
                                     12905
                                     12907
                                     12935
                                     12937
                                     12939             If                                                    It
                                     12941

          Residential                23100 Crispus Attucks Blvd., Eagle Harbor,     MD 20608                 7
                                     23102
                                     23106
                                     23110
                                     22907             If

          Residential                319 Main  St., Laruel, MD 20810                                       148

          Residential                8400 McClure Rd., Upper Marlboro, MD 20772                              9

          Residential                9305 Montpelier   Dr., Laurel, MD  20811                              116
                                     9307              11             11                                     11
                                     9309              it
                                     9306              If
                                     9308                             If                                     It
                                     9310                                                                    Is
                                     9312                                                                    it
                                     9314                                                                    If

                                                       D-35

                                             LIST OF FLOOD PRONE AREAS

                      STRUCTURE
                                                                                            lst Floor        I 00-yea
               TYPE                                 ADDRESS                                 (FT M. S. L.   (FT M.S.L

                                                   PATUXENT

            Residential                22803  Paul Sunbar   Ave., Eagle   Harbor, MD 20608                       7
                                       22900
                                       22907
                                       22908
                                       23001
                                       23003               it             If
                                       23100                              it

            Residential                5802  Green Landing Rd., Upper     Marlboro, MD 20772                     9
                                       5902                                                                      If

            Residential                17400 River Airport Rd., Brandywine, MD 20613                             8

            Residential                7100 Route 301(NW), Annapolis, MD 20715                                  43
                                       7110                11                                                    11
                                       7111

            Commercial                 26.Avondale St., Laurel, MD 20810                                       148
                                       42

            Commercial                 20  Baltimore Blvd., Laurel, MD 20810                                   146
                 11                    30
                 It                    42

            Commercial                 9701  Ft. Meade Rd., Laurel, MD 20810                                   145
                                       9703                11             11                                     11
                                       9705                it             11                                     11
                                       9707                               If                                     If
                 if                    9709
                                       9711                It
                                       9713
                 If                    9715
                                       9717                                                                      If
                                       9719                                                                      11
                                       9721                                                                      If
                 If                    9723
                                       9725
                                       9727                It             It
                                       9729
                                       9731

                                                           D-36

                                        LIST OF FLOOD PRONE AREAS

                  S T R U C T U R E                                                  E L E V A T 1 0 N
                                                                                   Ist Floor       100-year
            TYPE                             ADDRESS                               (FT M.S.L.) (FT M.S.L.-

                                           PATUXENT

          Commercial                I Main St., Laurel, MD 20810                                      148
                                    9
                                  19
                                  21    If
                                  22
               If                 99
               11                100    If
               If                101
                                 103                                                                   If
                                 105                                                                   If
                                 109                                                                   ',1
                                 311
                                 313    If
                                 315    [1
                                 317    If                                                             it
                                 351                   It                                              If
                                 353                   It
                                 355
                                 357
                                 359
                                 361
                                 363
               If                365                                                                   If
                                 367                                                                   If
                                 369                   If                                              11
                                 371                                                                   If
                                 373

          Commercial                1  2nd Ave., Laurel, MD 20810                                    145

                                                    D-37

                                               LIST OF FLOOD PRONE AREAS

                     S T R U C T U R E                                                       E L E V A T 1 0 N
                                                                                          lst Floor         100-yeat
               TYPE                               ADDRESS                                  (FT M.S.L.) (FT M.S.L

                                               WESTERN BRANCH

                                                  BALD HILL

          Residential.                   6109 C   St., Seabrook, MD 20706                                    137
                                         6110

          Residential                    9213  Lanham Severn Rd., Seabrook, MD 20706                         136
                                         9215                    if
                                         9217
                                         9305

          Residential                    8810  Magnolia Dr., Seabrook, MD 20706                              142
                11                       8811     11             If                                             11

          Residential                    9103  Sheridan Ct., Seabrook, MD 20706                              137
                if                       9104

          Residential                    9201  Wellington Ct.,   Seabrook, MD'20706
                                         9203                                                                   If

                                         9111  Wellington Pl.,   SeabrookMD 20706
                                         9113     11             11
                                         9115     if             If
                                         9117     If
                                         9119

          Residential                    9216  3rd  St., Seabrook, MD 20706
               If                        9217
                                         9219                                                                   If

          Residential                    9219  4th  St., Seabrook, MD 20706
                                         9225     if             11                                             If
                                         9226     It
                                         9227     If
               If                        9217  5th  St., SeabrookMD 20706

                                         9209  6th  St., Seabrook, MD 20706
                                         9212                    It
                                         9214                    If

                                                        D-38

                                          LIST OF FLOOD PRONIE AREAS

                   S T R    C T U R E                                                      E L E V A T 1 0 N
                                                                                         lst Floor        100--year
             TYPE                               ADDRESS                                  (FT M.S.L.)     FT M,S.L.

                                             FEDERAL SPRING

         Residential                   13011   Old Marlboro Pike, Upper Marlboro, MD 20772                    12
                                                               11
                                       13013
                                       14003                   If                                             37
                                       14005
               If                      14007
                                       14009

         Commercial                    14011
               if                      14015    11                                                             if

                                               FOLLY BRANCH

         Residential                   10321 Buena Vista Ave., Lanham, MD 20706                             118

                                       10234 Chautauqua.Ave., Lanham, MD 20706                              118
                                       10236                   11                  if                          11
                                       10300                   If                  It                          If

                                       5633 Hiland Ave., Lanham, MD 20706

         Residential                   10800 Lanham-Severn Rd., Lanham, MD 20706                            134
               11                      10802    11
               If                      10804    If
                                       10805    If

         Residential                   10707  Larch Dr.,   Glenn Dale, MD 20769                             134
                                       10711

                                       5636  Lincoln Ave., Lanham, MD 20706                                 118
                                       5730     11             11                                              It

               If                      7401  Northern Ave., Glenn Dale, MD 20769                            134
                                       7409                                        11                          11
                                       7413

                                                       D-39

                                            LIST OF FLOOD PRONE AREAS

                     S T R U C T U R E                                                        _E L E V A T 1 0 N
                                                                                            lst Floor         100-yeai
               TYPE                               ADDRESS                                   (FT M.S.L.) (FT M.S.L,

                                                  FOLLY BRANCH (cont'd)

          Residential                    9902 Poplar St., Lanham, MD 20706                                      118
                                         9903
                                         9906

          Residential                    10706 Potomac St., Glenn Dale, MD 20769                                134
                                         10708

                                         6507 Woodstream Dr., Lanham, MD 20706                                  140

          Commercial                     10802 Lanham-Severn Rd., Lanham, MO 20706                              134
                                         10804     it
                                         10806     11
                                         7317 NorthernAve., Glenn Dale, MD       20706

                                                COLLINGTON BRANCH

          Residential                    4712 Largo Rd., Upper Marlboro, MD 20772                                 30
                                         15117
                                         15119
                                         15202                                                                    32
                                         15204
                                         15206
                                         15208

          Residential                    15728  Pointer Ridge Dr., Upper Marlboro, MD 20772                       30
                                         15730                                                                     11
                                                                                                                   it
                                         15732
                                         15734                    it

          Comme-rcial                    6000 Laurel Bowie Rd.,     Bowie, MD 20716                             145

                                                         D-40

                                          LIST OF FLOOD PRONE AREAS

                   STRUCTURE                                                               ELEVATION
                                                                                        lst Floor        100--year
                                                                                                              i@ 1 11.
             TYPE                               ADDRESS                                 (FT-M.S.L.) (FT MII

                                              TURKEY BRANCH

         Residential                   3130 Pyles Dr., Upper Marlboro, MD 20772                             82
               11                      3131                                                                   H
                                       3133

                                       2600  Ritchie-Marlboro Rd., Upper Marlboro, MD 20772                108

                                              CABIN BRANCH

         Residential                   3508 Brown Station Rd., Upper Marlboro, MD 20772                     38

                                                NORTHEAST

         Commercial                    12211 Central Ave., Upper Marlboro, MD 20772                         78

                                                 SOUTHWEST BRANCH

         Residential                   1212 Darlington St., Forestville, MD 20028                          148
                                       1214

         Residential                   10304 New  Orchard Dr., Upper Marlboro, MD 20772                     88

                                       2017 Marbury,Dr., District Heights, MD 20028                        198

                                       10402 Rambling Hill Ct., Upper Marlboro, MD 20772                    83
                                       10404

                                       1514 Ritchie Rd., Forestville,    MD 20028                          162
                                       1504 Shady Glenn Dr., District    HeightS, MD 20027                 180

                                                       D-41

                                            LIST OF FLOOD -'r-Ro%,E AREAS

                     S T R U C T U R E                                                      E L E V A T 1 0 N
                                                                                          lst Floor         100-year
               TYPE                               ADDRESS                                 (FT M.S.L.) (FT M.S.L.

                                                SOUTHWEST BRANCH (cont'd)

          Residential                    11302 Sherrington Ct., Upper Marlboro, MD 20772                       72
                                         11304

          Residential                    11102 Webbwood Ct., Upper Marlboro, MD       20772                    74
                11                       11104
                If                       11106
                it                       11108
                                         11110
                                         11112                              If
                                         11114
                                         11105
                                         11109    It                                                             it

          Residential                    11014 Woodlawn Blvd., Upper Marlboro, MD 20772                        74

          Commercial                    -8617 Central Ave., Capitol Heights, MD 20027                          120
                                         9001                               it
                                         9005                               If
                                         9033                               If                                   If
                                         9101                                                                    it
                                         9171                                                                    11
                                         9175                                                                    If
                                         9179                               it
                                         9181
                                         9183
                                         9185
                                         9195     If

          Commercial                     401 Old  Ritchie Rd., Forestville, MD 20028                           128
                                         407      11                        11                                   11
                                         408      If

                                               WESTERN (MAIN STEM)

          Residential                    14946 Main St., Upper Marlboro, MD 20772                              30
                11                       14948    11                        11                                   If

                If                       15104    If

                                                         D-42

                                           LIST OF FLOOD PRONE AREAS

                   S T R U C T U R E                                                        E L E V A T 1 0 N
                                                                                          Ist- Floor       100-year
             TYPE                                ADDRESS                                  (FT M.S-L.)___(FT M.S.L.

                                              WESTERN BRANCH (MAIN STEM) cont'd)

         Residential                    15106 Main.St., Upper    Marlboro, MD 20772                              30
                                        15108                                                                    If
                                        15109
                                        15115
               it                       15220                    it
                                        15224
                                        15226
                                                 It
                                        15241
                                        15242                                                                    If
                                        15243    it                                                              .[I
                                        15246                    it                                              11
                                        15247                                                                    If
                                        15248

                                        15100 Peerless Ave., Upper Marlboro, MD 20772
                                        15102
                                        15104

        Commercial                      11801 Chesterton Dr.,   Upper Marlboro, MD 20772                         If

                                        15400 Chrysler Dr., Upper Marlboro, MD 20772
                                        15410                                                                    If
                                        5200           Way,

        Commercial                      5300  Crain Highway, SE, Upper   Marlboro, MD 20772                   30
                                        5301
                                        5701  Crain Highway, SW,.Upper   Marlboro, MD 20772                   30
                                        5707
                                        5715
                                        5717
                                        5719
                                        5721
                                        5723
                                        5725
                                        5727
                                        5731
             If                         5733     11                      If                                      I
                                        5735                             If                                      I;

                                                        D-43

                                             LIST OF FLOOD ;@@RONE AREAS

                     S T R U C T U R E                                                        E L E V A T 1 0 N
                                                                                            lst Floor         100-year
               TYPE                                 ADDRESS                                 (FT M.S.L.)___(FT M-.--S-.L.

                                               WESTERN BRANCH (MAIN STEM)

          Commercial                      5737 Crain Hwy., SW, Upper Marlboro, MD 20772                          30
                 If                       5739
                 it                       5741
                                          5743
                                          5745
                                          5747                              it
                                          5749                                                                     If
                 it                       5751                                                                     11
                 11                       5753                              it                                     It
                 it                       5755      It
                                          5757      11
                                          5759      If                      It
                 If                       6000 Crain  Hwy., SE, Upper Marlboro, MD 20772                         30
                 of                       6600      11                      11                                     11

          Commercial                      5401 Douglas St., Upper Marlboro, MD 20772
                 If                       5407

                                          5405 East  Court Dr., Upper Marlboro, MD 20772                         30
                                          5409
                 If                       5411      11
                                          5413      it

                                          14741 Gov. Oden Bowie Dr., Upper Marlboro, MD 20772                    30

                                          14735 Main St., Upper Marlboro, MD 20772                               30
                                          14940 Main St., Upper Marlboro, MD 20772

                                          15004 Marlboro Pike, Upper Marlboro,-MD 20772
                                          15005     If
                                          15006     If
                                          15008
                                          15011
                                          151-03                                                                   If
                                          15113
                                          15117
                                          15200
                                          15201
                                          15203
                                          15204     If
                                          15205

                                                          D-44

                                          LIST OF FLOODPRONE AREAS

                   S T R U C T U R E                                                       E L E V A     T
                                                                                                          ION
                                                                                         lst Foor         100-year
             TYPE                             ADDRESS                                    (FT M.S.L.) (FT M,S.L.

                                             WESTERN BRANCH (MAIN STEM)

         Commercial                    15207  Marlboro  Pike, Upper Marlboro, MD 20772                       30
                                       15209                                                                   If
                                       15211
                                       15213                             if
                                       15222
                                       15225          If                                                       if
                                       15301          11                                                       1,
              If                       15305                             If                                    if
              if                       15315                                                                   E
                                       15055

         Commercial                    14811  Pratt St., Upper Marl-boro, MD 20772                           30
              11                       14815     11                   It                                       It

         Commercial                   .5404 Water St., Upper Marlboro, MD 20772                              30
                                       5415      11             11                                             It
                                       5700

                                       5408  West Court Dr., Upper Marlboro,     MD 20772                    30

         *Some structures contain multi-addresses of commercial or residential uses.

                                                        D-45

                                                                                                                                                 I @ . -1

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