VOLUME 1 OF 4 YORK COUNTY, (ALL JURISDICTIONS)

COMMUNITY NAME NUMBER COMMUNITY NAME NUMBER ACTON, TOWN OF 230190 OGUNQUIT, TOWN OF 230632 ALFRED, TOWN OF 230191 OLD ORCHARD BEACH, TOWN OF 230153 ARUNDEL, TOWN Of 230192 PARSONSFIELD, TOWN OF 230154 BERWICK, TOWN OF 230144 SACO, CITY OF 230155 BIDDEFORD, CITY OF 230145 SANFORD, CITY OF 230156 BUXTON, TOWN OF 230146 SHAPLEIGH, TOWN OF 230198 CORNISH, TOWN OF 230147 SOUTH BERWICK, TOWN OF 230157 DAYTON, TOWN OF 230148 WATERBORO, TOWN OF 230199 ELIOT, TOWN OF 230149 WELLS, TOWN OF 230158 HOLLIS, TOWN OF 230150 YORK, TOWN OF 230159 KENNEBUNK, TOWN OF 230151 KENNEBUNKPORT, TOWN OF 230170 KITTERY, TOWN OF 230171 LEBANON, TOWN OF 230193 LIMERICK, TOWN OF 230194 LIMINGTON, TOWN OF 230152 LYMAN, TOWN OF 230195 NEWFIELD, TOWN OF 230196 NORTH BERWICK, TOWN OF 230197 EFFECTIVE:

FLOOD INSURANCE STUDY NUMBER 23005CV001A Version Number 2.3.2.1

TABLE OF CONTENTS Volume 1 Page

SECTION 1.0 – INTRODUCTION 1 1.1 The National Flood Insurance Program 1 1.2 Purpose of this Flood Insurance Study Report 2 1.3 Jurisdictions Included in the Flood Insurance Study Project 2 1.4 Considerations for using this Flood Insurance Study Report 20

SECTION 2.0 – FLOODPLAIN MANAGEMENT APPLICATIONS 31 2.1 Floodplain Boundaries 31 2.2 Floodways 43 2.3 Base Flood Elevations 44 2.4 Non-Encroachment Zones 44 2.5 Coastal Flood Hazard Areas 45 2.5.1 Water Elevations and the Effects of Waves 45 2.5.2 Floodplain Boundaries and BFEs for Coastal Areas 46 2.5.3 Coastal High Hazard Areas 47 2.5.4 Limit of Moderate Wave Action 48

SECTION 3.0 – INSURANCE APPLICATIONS 49 3.1 National Flood Insurance Program Insurance Zones 49 3.2 Coastal Barrier Resources System 51

SECTION 4.0 – AREA STUDIED 51 4.1 Basin Description 51 4.2 Principal Flood Problems 52 4.3 Non-Levee Flood Protection Measures 54 4.4 Levees 57

SECTION 5.0 – ENGINEERING METHODS 58 5.1 Hydrologic Analyses 58 5.2 Hydraulic Analyses 78 5.3 Coastal Analyses 106 5.3.1 Total Stillwater Elevations 110 5.3.2 Waves 111 5.3.3 Coastal Erosion 111 5.3.4 Wave Hazard Analyses 112 5.4 Alluvial Fan Analyses 123

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TABLE OF CONTENTS - continued Volume 1 - continued

Figures Page

Figure 1: FIRM Index 23 Figure 2: FIRM Notes to Users 24 Figure 3: Map Legend for FIRM 27 Figure 4: Floodway Schematic 43 Figure 5: Wave Runup Transect Schematic 46 Figure 6: Coastal Transect Schematic 48 Figure 7: Frequency Discharge-Drainage Area Curves 76 Figure 8: 1% Annual Chance Total Stillwater Elevations for Coastal Areas 110 Figure 9: Transect Location Map 121

Tables Page

Table 1: Listing of NFIP Jurisdictions 2 Table 2: Flooding Sources Included in this FIS Report 33 Table 3: Flood Zone Designations by Community 50 Table 4: Coastal Barrier Resources System Information 51 Table 5: Basin Characteristics 52 Table 6: Principal Flood Problems 52 Table 7: Historic Flooding Elevations 54 Table 8: Non-Levee Flood Protection Measures 54 Table 9: Levees 57 Table 10: Summary of Discharges 64 Table 11: Summary of Non-Coastal Stillwater Elevations 77 Table 12: Stream Gage Information used to Determine Discharges 78 Table 13: Summary of Hydrologic and Hydraulic Analyses 89 Table 14: Roughness Coefficients 105 Table 15: Summary of Coastal Analyses 107 Table 16: Tide Gage Analysis Specifics 111 Table 17: Coastal Transect Parameters 113 Table 18: Summary of Alluvial Fan Analyses 123 Table 19: Results of Alluvial Fan Analyses 123

Volume 2

SECTION 6.0 – MAPPING METHODS 124 6.1 Vertical and Horizontal Control 124 6.2 Base Map 125 6.3 Floodplain and Floodway Delineation 126 6.4 Coastal Flood Hazard Mapping 190

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TABLE OF CONTENTS - continued Volume 2 - continued

6.5 FIRM Revisions 200 6.5.1 Letters of Map Amendment 200 6.5.2 Letters of Map Revision Based on Fill 200 6.5.3 Letters of Map Revision 201 6.5.4 Physical Map Revisions 202 6.5.5 Contracted Restudies 202 6.5.6 Community Map History 202

SECTION 7.0 – CONTRACTED STUDIES AND COMMUNITY COORDINATION 204 7.1 Contracted Studies 204 7.2 Community Meetings 213

SECTION 8.0 – ADDITIONAL INFORMATION 217

SECTION 9.0 – BIBLIOGRAPHY AND REFERENCES 219

Tables Page

Table 20: Countywide Vertical Datum Conversion 124 Table 21: Stream-Based Vertical Datum Conversion 125 Table 22: Base Map Sources 126 Table 23: Summary of Topographic Elevation Data used in Mapping 127 Table 24: Floodway Data 128 Table 25: Flood Hazard and Non-Encroachment Data for Selected Streams 190 187 Table 26: Summary of Coastal Transect Mapping Considerations 191 Table 27: Incorporated Letters of Map Change 201 Table 28: Community Map History 203 Table 29: Summary of Contracted Studies Included in this FIS Report 205 Table 30: Community Meetings 214 Table 31: Map Repositories 217 Table 32: Additional Information 219 Table 33: Bibliography and References 220

iii

TABLE OF CONTENTS - continued Volume 3 – continued

Exhibits

Flood Profiles Panel 01-02 P Blacksmith Brook 03 P Bridges Swamp 04 P 05-06 P Chickering Creek 07 P Cider Hill Creek 08-09 P Coffin Brook 10 P Coffin Brook Tributary 1 11-12 P Cooks Brook 13-16 P Day Brook 17 P Depot Brook 18 P Dolly Gordon Brook 19-20 P Driscoll Brook 21-22 P Ferguson Brook 23-24 P Fuller Brook 25 P Goodall Brook 26 P Goosefare Brook 27-29 P 30-41 P Green Brook 42-43 P Hill Creek 44 P 45 P Keay Brook 46-47 P 48-53 P Little 54-66 P (Town of Berwick) 67-70 P Little River (Town of Cornish) 71 P Little River (Town of Kennebunk) 72 P Little River 73-74 P 75-78 P (Lower Reach) 79 P Merriland River (Upper Reach) 80 P Middle Branch 81 P Mill Brook 82 P Moors Brook 83 P

iv

TABLE OF CONTENTS - continued Volume 4

Exhibits

Flood Profiles Panel Mousam River (City of Sanford) 84-89 P Mousam River (Lower Reach) 90-91 P Mousam River (Town of Kennebunk) 92-95 P Mulloy Brook 96 P 97-99 P Ogunquit River Tributary 100 P Ossipee River 101-106 P 107-124 P Saco River - Left Channel 125 P 126-141 P Sawyer Brook 142 P Smith Brook 143 P South Branch of West Brook 144 P Spinney Creek 145 P Spruce Creek 146 P Stevens Brook 147 P Thatcher Brook 148 P Tributary 1 to Cape Neddick River 149 P Tributary 1 to Green Brook 150 P Tributary to Middle Branch Mousam River 151 P Unnamed Tributary to Stony Brook 152 P 153 P West Brook 154 P Worster Brook 155-157 P Worster Brook Tributary 3 158-159 P

Published Separately

Flood Insurance Rate Map (FIRM)

v

FLOOD INSURANCE STUDY REPORT YORK COUNTY, MAINE

SECTION 1.0 – INTRODUCTION

1.1 The National Flood Insurance Program The National Flood Insurance Program (NFIP) is a voluntary Federal program that enables property owners in participating communities to purchase insurance protection against losses from flooding. This insurance is designed to provide an alternative to disaster assistance to meet the escalating costs of repairing damage to buildings and their contents caused by floods.

For decades, the national response to flood disasters was generally limited to constructing flood-control works such as dams, levees, sea-walls, and the like, and providing disaster relief to flood victims. This approach did not reduce losses nor did it discourage unwise development. In some instances, it may have actually encouraged additional development. To compound the problem, the public generally could not buy flood coverage from insurance companies, and building techniques to reduce flood damage were often overlooked.

In the face of mounting flood losses and escalating costs of disaster relief to the general taxpayers, the U.S. Congress created the NFIP. The intent was to reduce future flood damage through community floodplain management ordinances, and provide protection for property owners against potential losses through an insurance mechanism that requires a premium to be paid for the protection.

The U.S. Congress established the NFIP on August 1, 1968, with the passage of the National Flood Insurance Act of 1968. The NFIP was broadened and modified with the passage of the Flood Disaster Protection Act of 1973 and other legislative measures. It was further modified by the National Flood Insurance Reform Act of 1994 and the Flood Insurance Reform Act of 2004. The NFIP is administered by the Federal Emergency Management Agency (FEMA), which is a component of the Department of Homeland Security (DHS).

Participation in the NFIP is based on an agreement between local communities and the Federal Government. If a community adopts and enforces floodplain management regulations to reduce future flood risks to new construction and substantially improved structures in Special Flood Hazard Areas (SFHAs), the Federal Government will make flood insurance available within the community as a financial protection against flood losses. The community’s floodplain management regulations must meet or exceed criteria established in accordance with Title 44 Code of Federal Regulations (CFR) Part 60, Criteria for Land Management and Use .

SFHAs are delineated on the community’s Flood Insurance Rate Maps (FIRMs). Under the NFIP, buildings that were built before the flood hazard was identified on the community’s FIRMs are generally referred to as “Pre-FIRM” buildings. When the NFIP was created, the U.S. Congress recognized that insurance for Pre-FIRM buildings would be prohibitively expensive if the premiums were not subsidized by the Federal

1

Government. Congress also recognized that most of these floodprone buildings were built by individuals who did not have sufficient knowledge of the flood hazard to make informed decisions. The NFIP requires that full actuarial rates reflecting the complete flood risk be charged on all buildings constructed or substantially improved on or after the effective date of the initial FIRM for the community or after December 31, 1974, whichever is later. These buildings are generally referred to as “Post-FIRM” buildings.

1.2 Purpose of this Flood Insurance Study Report This Flood Insurance Study (FIS) Report revises and updates information on the existence and severity of flood hazards for the study area. The studies described in this report developed flood hazard data that will be used to establish actuarial flood insurance rates and to assist communities in efforts to implement sound floodplain management.

In some states or communities, floodplain management criteria or regulations may exist that are more restrictive than the minimum Federal requirements. Contact your State NFIP Coordinator to ensure that any higher State standards are included in the community’s regulations.

1.3 Jurisdictions Included in the Flood Insurance Study Project This FIS Report covers the entire geographic area of York County, Maine.

The jurisdictions that are included in this project area, along with the Community Identification Number (CID) for each community and the Geological Survey (USGS) 8-digit Hydrologic Unit Code (HUC-8) sub-basins affecting each, are shown in Table 1. The FIRM panel numbers that affect each community are listed. If the flood hazard data for the community is not included in this FIS Report, the location of that data is identified.

The location of flood hazard data for participating communities in multiple jurisdictions is also indicated in the table.

Table 1: Listing of NFIP Jurisdictions If Not Included, HUC-8 Located on Location of Flood Community CID Sub-Basin(s) FIRM Panel(s) Hazard Data 23031C0201G 23031C0202G 23031C0205G 01060002 Acton, Town of 230190 23031C0206G 01060003 23031C0208G 23031C0209G 23031C0201G

2 Table 1: Listing of NFIP Jurisdictions • continued

If Not Included, HUC-8 Located on Location of Flood Community CID Sub-Basin(s) FIRM Panel(s) Hazard Data 23031C0202G 23031C0205G 23031C0208G 23031C0209G 23031C0212G 23031C0214G 01060002 Acton, Town of - continued 230190 23031C0220G¹ 01060003 23031C0240G¹ 23031C0351G 23031C0352G 23031C0354G 23031C0360G 23031C0380G 23031C0235G 23031C0245G 23031C0235G 23031C0244G 23031C0245G 23031C0263G 23031C0264G 23031C0381G 23031C0382G 01060002 Alfred, Town of 230191 23031C0384G 01060003 23031C0401G 23031C0402G 23031C0403G 23031C0404G 23031C0406G 23031C0410G 23031C0412G 23031C0416G 23031C0417G

1 No Special Flood Hazard Areas Identified

3 Table 1: Listing of NFIP Jurisdictions • continued

If Not Included, HUC-8 Located on Location of Flood Community CID Sub-Basin(s) FIRM Panel(s) Hazard Data 23031C0430G 23031C0432G 23031C0435G 23031C0455G 23031C0430G 23031C0432G 23031C0435G 01060002 Arundel, Town of 230192 23031C0441G 01060003 23031C0442G 23031C0443G 23031C0444G 23031C0455G 23031C0461G 23031C0463G 23031C0601G 23031C0507G 23031C0508G 23031C0509G 23031C0516G 23031C0517G 23031C0519G 23031C0526G 23031C0527G 23031C0528G Berwick, Town of 230144 01060003 23031C0529G 23031C0535G 23031C0536G 23031C0537G 23031C0538G 23031C0539G 23031C0543G 23031C0545G 23031C0627G

4 Table 1: Listing of NFIP Jurisdictions • continued

If Not Included, HUC-8 Located on Location of Flood Community CID Sub-Basin(s) FIRM Panel(s) Hazard Data 23031C0545G Berwick, Town of - continued 230144 01060003 23031C0627G 23031C0631G 23031C0459G 23031C0478G 23031C0479G 23031C0485G² 23031C0495G² 23031C0292G 23031C0293G 23031C0294G 23031C0313G 23031C0430G 23031C0432G 23031C0435G 23031C0451G 23031C0452G 01060001 23031C0455G Biddeford, City of 230145 01060002 23031C0456G 01060003 23031C0457G 23031C0458G 23031C0459G 23031C0467G 23031C0478G 23031C0479G 23031C0486G 23031C0455G 23031C0458G 23031C0459G 23031C0462G 23031C0466G 23031C0467G 23031C0469G 2 Panel Not Printed

5 Table 1: Listing of NFIP Jurisdictions • continued If Not Included, HUC-8 Located on Location of Flood Community CID Sub-Basin(s) FIRM Panel(s) Hazard Data 23031C0478G 23031C0479G 01060001 23031C0485G² Biddeford, City of - continued 230145 01060002 23031C0486G 01060003 23031C0490G¹ 23031C0495G² 23031C0160G 23031C0162G 23031C0164G 23031C0168G 23031C0169G 23031C0170G 23031C0190G 23031C0281G 23031C0282G¹ 23031C0284G 23031C0305G 23031C0153G 01060001 23031C0154G Buxton, Town of 230146 01060002 23031C0160G 23031C0161G 23031C0162G 23031C0163G 23031C0164G 23031C0168G 23031C0170G 23031C0277G 23031C0281G 23031C0282G¹ 23031C0283G 23031C0284G 23031C0291G

1 No Special Flood Hazard Areas Identified 2 Panel Not Printed

6 Table 1: Listing of NFIP Jurisdictions • continued If Not Included, HUC-8 Located on Location of Flood Community CID Sub-Basin(s) FIRM Panel(s) Hazard Data 23031C0033G 23031C0036G 23031C0037G 23031C0040G 23031C0041G Cornish, Town of 230147 01060002 23031C0042G 23031C0043G¹ 23031C0044G 23031C0105G 23031C0110G 23031C0259G 23031C0267G 23031C0277G 23031C0278G 23031C0279G 23031C0283G 23031C0286G 23031C0287G Dayton, Town of 230148 01060002 23031C0288G 23031C0289G 23031C0291G 23031C0292G 23031C0293G 23031C0294G 23031C0430G 23031C0435G 23031C0633G 23031C0634G 23031C0637G Eliot, Town of 230149 01060003 23031C0639G 23031C0645G 23031C0661G 23031C0663G 1 No Special Flood Hazard Areas Identified

7 Table 1: Listing of NFIP Jurisdictions • continued If Not Included, HUC-8 Located on Location of Flood Community CID Sub-Basin(s) FIRM Panel(s) Hazard Data 23031C0702G 23031C0706G Eliot, Town of - continued 230149 01060003 23031C0707G 23031C0709G 23031C0134G 23031C0141G 23031C0142G 23031C0143G 23031C0144G 23031C0153G 23031C0161G 23031C0163G 23031C0164G Hollis, Town of 230150 01060002 23031C0259G 23031C0260G 23031C0276G 23031C0277G 23031C0278G 23031C0279G 23031C0281G 23031C0283G 23031C0286G 23031C0410G 23031C0417G 23031C0420G 23031C0430G 23031C0435G Kennebunk, Town of 230151 01060003 23031C0438G 23031C0439G 23031C0440G 23031C0441G 23031C0443G 23031C0444G

8 Table 1: Listing of NFIP Jurisdictions • continued If Not Included, HUC-8 Located on Location of Flood Community CID Sub-Basin(s) FIRM Panel(s) Hazard Data 23031C0463G 23031C0577G 23031C0581G 23031C0582G

Kennebunk, Town of - 23031C0583G 230151 01060003 continued 23031C0584G 23031C0595G² 23031C0601G 23031C0603G 23031C0615G² 23031C0455G 23031C0455G 23031C0461G 23031C0462G 23031C0463G 23031C0464G 23031C0466G 23031C0467G 23031C0468G 01060002 Kennebunkport, Town of 230170 23031C0469G 01060003 23031C0490G¹ 23031C0601G 23031C0602G 23031C0603G 23031C0604G 23031C0606G 23031C0610G² 23031C0615G² 23031C0620G² 23031C0645G 23031C0663G Kittery, Town of 230171 01060003 23031C0664G 23031C0707G

1 No Special Flood Hazard Areas Identified 2 Panel Not Printed 9 Table 1: Listing of NFIP Jurisdictions • continued If Not Included, HUC-8 Located on Location of Flood Community CID Sub-Basin(s) FIRM Panel(s) Hazard Data 23031C0709G 23031C0726G 23031C0727G 23031C0728G 23031C0729G 23031C0731G 23031C0732G 23031C0733G Kittery, Town of - continued 230171 01060003 23031C0734G 23031C0737G 23031C0741G 23031C0745G² 23031C0763G 23031C0775G² 23031C0776G 23031C0800G¹ 23031C0351G 23031C0352G 23031C0354G 23031C0360G 23031C0361G 23031C0362G 23031C0363G 23031C0364G Lebanon, Town of 230193 01060003 23031C0370G 23031C0380G 23031C0390G 23031C0501G 23031C0502G 23031C0504G 23031C0506G 23031C0507G 23031C0508G

1 No Special Flood Hazard Areas Identified 2 Panel Not Printed 10 Table 1: Listing of NFIP Jurisdictions • continued

If Not Included, HUC-8 Located on Location of Flood Community CID Sub-Basin(s) FIRM Panel(s) Hazard Data Lebanon, Town of - 23031C0509G 230193 01060003 continued 23031C0526G 23031C0044G 23031C0105G 23031C0110G 23031C0114G 23031C0115G 23031C0116G Limerick, Town of 230194 01060002 23031C0117G 23031C0118G 23031C0119G 23031C0130G 23031C0136G 23031C0138G 23031C0042G 23031C0044G 23031C0061G 23031C0062G 23031C0065G 23031C0066G 23031C0067G 23031C0068G Limington, Town of 230152 01060002 23031C0069G 23031C0110G 23031C0130G 23031C0131G 23031C0132G 23031C0133G 23031C0134G 23031C0136G 23031C0137G

11 Table 1: Listing of NFIP Jurisdictions • continued If Not Included, HUC-8 Located on Location of Flood Community CID Sub-Basin(s) FIRM Panel(s) Hazard Data 23031C0141G Limington, Town of - 230152 01060002 23031C0142G continued 23031C0143G 23031C0259G 23031C0260G 23031C0264G 23031C0265G 23031C0266G 23031C0267G 23031C0268G 23031C0269G 23031C0286G 23031C0288G 23031C0289G 01060002 Lyman, Town of 230195 23031C0430G 01060003 23031C0264G 23031C0265G 23031C0268G 23031C0269G 23031C0288G 23031C0402G 23031C0406G 23031C0407G 23031C0410G 23031C0417G 23031C0430G 23031C0086G 23031C0090G¹ 23031C0095G Newfield, Town of 230196 01060002 23031C0113G 23031C0114G 23031C0115G 23031C0118G 1 No Special Flood Hazard Areas Identified

12 Table 1: Listing of NFIP Jurisdictions • continued

If Not Included, HUC-8 Located on Location of Flood Community CID Sub-Basin(s) FIRM Panel(s) Hazard Data 23031C0201G 23031C0202G

Newfield, Town of - 23031C0206G 230196 01060002 continued 23031C0207G 23031C0226G 23031C0230G¹ 23031C0390G 23031C0391G 23031C0392G 23031C0393G¹ 23031C0394G 23031C0413G 23031C0526G 23031C0527G 23031C0529G North Berwick, Town of 230197 01060003 23031C0532G 23031C0534G 23031C0535G 23031C0545G 23031C0551G 23031C0553G 23031C0554G 23031C0561G 23031C0562G 23031C0563G 23031C0569G 23031C0588G 23031C0589G 23031C0595G² Ogunquit, Town of 230632 01060003 23031C0657G 23031C0676G 23031C0677G 23031C0700G¹

1 No Special Flood Hazard Areas Identified 2 Panel Not Printed 13 Table 1: Listing of NFIP Jurisdictions • continued

If Not Included, HUC-8 Located on Location of Flood Community CID Sub-Basin(s) FIRM Panel(s) Hazard Data 23031C0316G 23031C0317G 23031C0318G 23031C0319G 23031C0336G 23031C0338G Old Orchard Beach, Town of 230153 01060001 23031C0339G 23031C0343G 23031C0456G 23031C0457G 23031C0480G 23031C0485G² 23031C0011G 23031C0012G 23031C0013G 23031C0014G 23031C0016G 23031C0017G 23031C0018G 23031C0019G 23031C0036G 23031C0040G Parsonsfield, Town of 230154 01060002 23031C0080G 23031C0083G 23031C0084G 23031C0085G¹ 23031C0086G 23031C0090G¹ 23031C0095G 23031C0103G 23031C0105G 23031C0115G 1 No Special Flood Hazard Areas Identified 2 Panel Not Printed

14 Table 1: Listing of NFIP Jurisdictions • continued

If Not Included, HUC-8 Located on Location of Flood Community CID Sub-Basin(s) FIRM Panel(s) Hazard Data 23031C0282G¹ 23031C0284G 23031C0305G 23031C0310G 23031C0314G 23031C0315G 23031C0316G 23031C0317G 23031C0318G 23031C0456G 23031C0457G 23031C0459G 23031C0478G 23031C0479G

01060001 23031C0480G Saco, City of 230155 01060002 23031C0485G² 01060003 23031C0283G 23031C0284G 23031C0291G 23031C0292G 23031C0294G 23031C0305G 23031C0313G 23031C0314G 23031C0315G 23031C0318G 23031C0432G 23031C0451G 23031C0452G 23031C0456G 23031C0457G

1 No Special Flood Hazard Areas Identified 2 Panel Not Printed

15 Table 1: Listing of NFIP Jurisdictions • continued If Not Included, HUC-8 Located on Location of Flood Community CID Sub-Basin(s) FIRM Panel(s) Hazard Data 01060001 23031C0459G Saco, City of - continued 230155 01060002 23031C0485G² 01060003 23031C0495G² 23031C0377G 23031C0380G 23031C0381G 23031C0382G 23031C0383G 23031C0384G 23031C0390G 23031C0391G 23031C0392G 23031C0393G¹ 23031C0394G 23031C0403G Sanford, City of 230156 01060003 23031C0404G 23031C0411G 23031C0412G 23031C0413G 23031C0414G 23031C0416G 23031C0417G 23031C0420G 23031C0551G 23031C0552G 23031C0553G 23031C0554G 23031C0556G 23031C0114G 23031C0118G 01060002 Shapleigh, Town of 230198 23031C0206G 01060003 23031C0207G 23031C0208G 1 No Special Flood Hazard Areas Identified 2 Panel Not Printed 16 Table 1: Listing of NFIP Jurisdictions • continued If Not Included, HUC-8 Located on Location of Flood Community CID Sub-Basin(s) FIRM Panel(s) Hazard Data 23031C0209G 23031C0220G¹ 23031C0226G 23031C0230G¹ 23031C0235G Shapleigh, Town of - 01060002 230198 23031C0240G¹ continued 01060003 23031C0245G 23031C0377G 23031C0380G 23031C0381G 23031C0382G 23031C0543G 23031C0545G 23031C0561G 23031C0562G 23031C0563G 23031C0564G 23031C0568G 23031C0569G 23031C0627G 23031C0629G South Berwick, Town of 230157 01060003 23031C0631G 23031C0632G 23031C0633G 23031C0634G 23031C0637G 23031C0645G 23031C0651G 23031C0652G 23031C0653G 23031C0656G 01060002 23031C0114G Waterboro, Town of 230199 01060003 23031C0116G

1 No Special Flood Hazard Areas Identified

17 Table 1: Listing of NFIP Jurisdictions • continued If Not Included, HUC-8 Located on Location of Flood Community CID Sub-Basin(s) FIRM Panel(s) Hazard Data 23031C0117G 23031C0118G 23031C0119G 23031C0136G 23031C0137G 23031C0138G 23031C0139G¹ 23031C0141G 23031C0143G 23031C0235G 23031C0251G 23031C0252G 23031C0253G Waterboro, Town of - 01060002 230199 23031C0254G continued 01060003 23031C0259G 23031C0260G 23031C0265G 23031C0266G 23031C0235G 23031C0244G 23031C0245G 23031C0251G 23031C0253G 23031C0254G 23031C0263G 23031C0264G 23031C0265G 23031C0420G 23031C0438G 23031C0439G Wells, Town of 230158 01060003 23031C0552G 23031C0553G 23031C0554G

1 No Special Flood Hazard Areas Identified

18 Table 1: Listing of NFIP Jurisdictions • continued If Not Included, HUC-8 Located on Location of Flood Community CID Sub-Basin(s) FIRM Panel(s) Hazard Data 23031C0556G 23031C0557G 23031C0558G 23031C0559G 23031C0562G 23031C0564G 23031C0566G 23031C0567G 23031C0568G 23031C0569G 23031C0576G 23031C0577G Wells, Town of - continued 230158 01060003 23031C0578G 23031C0579G 23031C0581G 23031C0583G 23031C0584G 23031C0586G 23031C0587G 23031C0588G 23031C0589G 23031C0591G 23031C0595G² 23031C0615G² 23031C0568G 23031C0569G 23031C0634G 23031C0645G York, Town of 230159 01060003 23031C0651G 23031C0652G 23031C0653G 23031C0654G 23031C0656G

2 Panel Not Printed

19 Table 1: Listing of NFIP Jurisdictions • continued

If Not Included, HUC-8 Located on Location of Flood Community CID Sub-Basin(s) FIRM Panel(s) Hazard Data 23031C0657G 23031C0658G 23031C0659G 23031C0661G 23031C0662G 23031C0663G 23031C0664G 23031C0666G 23031C0667G 23031C0668G 23031C0669G 23031C0676G York, Town of - continued 230159 01060003 23031C0677G 23031C0678G 23031C0679G 23031C0686G 23031C0687G 23031C0688G 23031C0689G² 23031C0700G¹ 23031C0727G 23031C0731G 23031C0732G 23031C0734G 23031C0775G² 1 No Special Flood Hazard Areas Identified 2 Panel Not Printed

1.4 Considerations for using this Flood Insurance Study Report The NFIP encourages State and local governments to implement sound floodplain management programs. To assist in this endeavor, each FIS Report provides floodplain data, which may include a combination of the following: 10-, 4-, 2-, 1-, and 0.2-percent annual chance flood elevations (the 1% annual chance flood elevation is also referred to as the Base Flood Elevation (BFE)); delineations of the 1% annual chance and 0.2% annual chance floodplains; and 1% annual chance floodway. This information is

20 presented on the FIRM and/or in many components of the FIS Report, including Flood Profiles, Floodway Data tables, Summary of Non-Coastal Stillwater Elevations tables, and Coastal Transect Parameters tables (not all components may be provided for a specific FIS).

This section presents important considerations for using the information contained in this FIS Report and the FIRM, including changes in format and content. Figures 1, 2, and 3 present information that applies to using the FIRM with the FIS Report.

• Part or all of this FIS Report may be revised and republished at any time. In addition, part of this FIS Report may be revised by a Letter of Map Revision (LOMR), which does not involve republication or redistribution of the FIS Report. Refer to Section 6.5 of this FIS Report for information about the process to revise the FIS Report and/or FIRM.

It is, therefore, the responsibility of the user to consult with community officials by contacting the community repository to obtain the most current FIS Report components. Communities participating in the NFIP have established repositories of flood hazard data for floodplain management and flood insurance purposes. Community map repository addresses are provided in Table 31, “Map Repositories,” within this FIS Report.

• New FIS Reports are frequently developed for multiple communities, such as entire counties. A countywide FIS Report incorporates previous FIS Reports for individual communities and the unincorporated area of the county (if not jurisdictional) into a single document and supersedes those documents for the purposes of the NFIP.

The initial Countywide FIS Report for York County became effective on Date [TDB]. Refer to Table 28 for information about subsequent revisions to the FIRMs.

• Selected FIRM panels for the community may contain information (such as floodways and cross sections) that was previously shown separately on the corresponding Flood Boundary and Floodway Map (FBFM) panels. In addition, former flood hazard zone designations have been changed as follows:

Old Zone New Zone A1 through A30 AE V1 through V30 VE B X (shaded) C X (unshaded)

• FEMA does not impose floodplain management requirements or special insurance ratings based on Limit of Moderate Wave Action (LiMWA) delineations at this time. The LiMWA represents the approximate landward limit of the 1.5-foot breaking wave. If the LiMWA is shown on the FIRM, it is being provided by FEMA as information only. For communities that do adopt Zone VE building standards in the

21

area defined by the LiMWA, additional Community Rating System (CRS) credits are available. Refer to Section 2.5.4 for additional information about the LiMWA.

The CRS is a voluntary incentive program that recognizes and encourages community floodplain management activities that exceed the minimum NFIP requirements. Visit the FEMA Web site at www.fema.gov/national-flood-insurance- program-community-rating-system or contact your appropriate FEMA Regional Office for more information about this program.

• FEMA has developed a Guide to Flood Maps (FEMA 258) and online tutorials to assist users in accessing the information contained on the FIRM. These include how to read panels and step-by-step instructions to obtain specific information. To obtain this guide and other assistance in using the FIRM, visit the FEMA Web site at www.fema.gov/online-tutorials .

The FIRM Index in Figure 1 shows the overall FIRM panel layout within York County, and also displays the panel number and effective date for each FIRM panel in the county. Other information shown on the FIRM Index includes community boundaries, and flooding sources.

22 Figure 1: FIRM Index

OXFORD COUNTY 0033G

0011G 0012G 0016G 0017G 0036G 0037G 0041G 0042G 0061G 0062G 0066G 0067G

¬«25

0013G 0014G 0018G 0019G 0040G 0043G* 0044G 0065G 0068G 0069G TOWN OF 160 11 «¬ CORNISH «¬117 ¬« 230147 0080G 0085G* 0105G 0110G* 0130G 0131G 0132G 0160G TOWN OF PARSONSFIELD CARROLL COUNTY TOWN OF 230154 LIMINGTON 0083G 0084G TOWN OF 230152 0103G LIMERICK 0133G 0134G 0153G 0154G 230194 «¬117 0086G 0090G* 0095G 0115G 0116G 0117G 0136G 0137G 0142G 0161G 0162G 0141G 0170G 0190G TOWN OF NEWFIELD ¬«5 230196 ¬«35 ¬«22 0113G 0114G 0118G 0119G «¬110 0138G 0139G* 0143G 0144G 0163G 0164G 0168G 0169G TOWN OF «¬112 TOWN OF BUXTON HOLLIS 230146 0201G 0202G 0206G 230150 0207G 0226G 0251G 0252G 0235G 0260G 0276G 0277G 0281G 0305G 0310G ¬«11 0282G* TOWN OF WATERBORO ¬«4 230199 CUMBERLAND COUNTY 0205G 0208G 0209G 0230G* 0253G 0254G 0259G 0278G 0279G 0283G 0284G «¬117

0212G 0220G* 0240G* 0245G 0265G 0267G 0266G 0286G 0287G 0291G 0292G 0315G 0316G 0317G 0336G TOWN OF «¬109 ¤£202 DAYTON CITY OF SACO 230148 ¬«5 230155 ¤£1 0214G TOWN OF ¬«98 ¬«9 0244G 0264G 0269G SHAPLEIGH 0263G 0268G 0288G 0289G 0319G TOWN OF ACTON 0293G 0294G 0313G 0314G 0318G 0338G 0339G 0343G 230190 230198 TOWN OF LYMAN TOWN OF OLD ORCHARD BEACH 230195 ¨¦§95 195 0351G 0352G 0360G 0380G ¨¦§ 230153 0377G 0381G 0382G 0401G 0402G 0406G 0407G 0430G 0435G 0432G 0451G 0452G 0456G 0457G 0480G 0485G** TOWN OF ALFRED ¬«35 «¬111 230191 «¬111 0354G 0384G 0403G 0404G 0383G 0410G 0455G 0458G «¬224 TOWN OF ¤£1 0459G 0478G 0479G ARUNDEL CITY OF BIDDEFORD ¬«11 0361G 0362G 230192 230145 «¬208 0370G 0390G 0391G 0392G 0411G 0412G 0416G 0417G 0440G 0441G 0442G 0461G 0462G 0466G 0467G 0486G TOWN OF 0495G** CITY OF SANFORD ¬«9 KENNEBUNK 230156 ¤£1 TOWN OF LEBANON 230151 0363G 0364G* 0393G* 0394G 0413G 0414G 0420G 0438G 0439G 0443G 0444G 0463G 0464G 0468G 230193 ¬«99 0469G 0490G* ¬«4 ¬«35 TOWN OF KENNEBUNKPORT 0501G 0502G 0506G 230170 0507G 0526G 0527G 0535G 0532G 0551G 0552G 0556G 0557G 0576G 0577G 0581G 0582G 0602G TOWN OF 0601G 0606G ¤£202 NORTH BERWICK 109 ¬«9 230197 «¬ ¨¦§95 0504G 0509G 0508G 0528G 0529G 0534G 0554G 0558G 0553G 0559G 0578G 0579G 0583G 0584G 0603G 0604G 0610G** TOWN OF WELLS 230158 0516G 0517G 0536G 0537G 0545G 0561G 0562G 0566G 0567G 0586G 0587G 0591G 0615G** 0620G** CARROLL COUNTY TOWN OF BERWICK 230144 ¬«9 ¨¦§95 0519G 0538G 0539G 0543G 0563G 0564G 0568G 0569G 0588G 0589G 0595G** ¬«4 TOWN OF SOUTH BERWICK TOWN OF OGUNQUIT 230157 230632 0627G 0631G 0651G 0652G 0657G 0676G 0632G 0656G 0677G 0700G*

STRAFFORD COUNTY ¤£1

0629G 0634G 0653G 0654G 0658G 0633G 0659G 0678G 0679G TOWN OF YORK «¬236 230159 0661G 0637G 0645G 0662G 0666G 0667G 0686G 0687G

¤£1A ¬«91 ¤£1 0639G TOWN OF 0663G 0664G 0668G 0669G 0688G 0689G** ELIOT 230149 ¨¦§95 ¬«101 0702G 0706G 0707G 0726G 0727G 0731G 0732G 0775G** TOWN OF KITTERY 230171 «¬103 0709G 0728G 0729G 0733G 0734G

0737G 0741G ROCKINGHAM COUNTY

0745G** 0763G

0776G 0800G*

ATTENTION: The corporate limits shown on this FIRM Index are based on the best Information available at the time of publication. As such, they may be more current than those shown on FIRM panels issued before TBD

1 inch = 29,000 feet 1:348,000

feet NATIONAL FLOOD INSURANCE PROGRAM 0 8,000 16,000 32,000 48,000 64,000 FLOOD INSURANCE RATE MAP INDEX Map Projection: Universal Transverse Mercator Zone 19 North; YORK COUNTY, MAINE (All Jurisdictions) North American Datum 1983 PANELS PRINTED: 0011, 0012, 0013, 0014, 0016, 0017, 0018, 0019, 0033, 0036, 0037, 0040, 0041, 0042, 0044, 0061, 0062, 0065, 0066, 0067, 0068, 0069, 0080, 0083, 0084, 0086, 0095, 0103, 0105, 0110, 0113, 0114, 0115, 0116, 0117, 0118, 0119, 0130, 0131, 0132, 0133, 0134, 0136, 0137, 0138, THE INFORMATION DEPICTED ON THIS MAP AND SUPPORTING 0141, 0142, 0143, 0144, 0153, 0154, 0160, 0161, 0162, 0163, 0164, 0168, 0169, 0170, 0190, 0201, 0202, 0205, 0206, 0207, 0208, 0209, 0212, 0214, 0226, 0235, 0244, 0245, 0251, 0252, DOCUMENTATION ARE ALSO AVAILABLE IN DIGITAL FORMAT AT FEMA 0253, 0254, 0259, 0260, 0263, 0264, 0265, 0266, 0267, 0268, 0269, 0276, 0277, 0278, 0279, 0281, 0283, 0284, 0286, 0287, 0288, 0289, 0291, 0292, 0293, 0294, 0305, 0310, 0313, 0314, REVISED HTTP://MSC.FEMA.GOV 0315, 0316, 0317, 0318, 0319, 0336, 0338, 0339, 0343, 0351, 0352, 0354, 0360, 0361, 0362, 0363, 0364, 0370, 0377, 0380, 0381, 0382, 0383, 0384, 0390, 0391, 0392, 0394, 0401, 0402, PRELIMINARY 0403, 0404, 0406, 0407, 0410, 0411, 0412, 0413, 0414, 0416, 0417, 0420, 0430, 0432, 0435, MAP NUMBER 0438, 0439, 0440, 0441, 0442, 0443, 0444, 0451, 0452, 0455, 0456, 0457, 0458, 0459, 0461, 23031CIND0A 0462, 0463, 0464, 0466, 0467, 0468, 0469, 0478, 0479, 0480, 0486, 0501, 0502, 0504, 0506, 0507, 0508, 0509, 0516, 0517, 0519, 0526, 0527, 0528, 0529, 0532, 0534, 0535, 0536, 0537, SEE FLOOD INSURANCE STUDY FOR ADDITIONAL INFORMATION 0538, 0539, 0543, 0545, 0551, 0552, 0553, 0554, 0556, 0557, 0558, 0559, 0561, 0562, 0563, 0564, 0566, 0567, 0568, 0569, 0576, 0577, 0578, 0579, 0581, 0582, 0583, 0584, 0586, 0587, EFFECTIVE DATE 0588, 0589, 0591, 0601, 0602, 0603, 0604, 0606, 0627, 0629, 0631, 0632, 0633, 0634, 0637, 0639, 0645, 0651, 0652, 0653, 0654, 0656, 0657, 0658, 0659, 0661, 0662, 0663, 0664, 0666, * PANEL NOT PRINTED - NO SPECIAL FLOOD HAZARD AREAS 0667, 0668, 0669, 0676, 0677, 0678, 0679, 0686, 0687, 0688, 0702, 0706, 0707, 0709, 0726, ** PANEL NOT PRINTED - OPEN WATER AREA COUNTY LOCATOR 0727, 0728, 0729, 0731, 0732, 0733, 0734, 0737, 0741, 0763, 0776

Each FIRM panel may contain specific notes to the user that provide additional information regarding the flood hazard data shown on that map. However, the FIRM panel does not contain enough space to show all the notes that may be relevant in helping to better understand the information on the panel. Figure 2 contains the full list of these notes.

Figure 2: FIRM Notes to Users NOTES TO USERS For information and questions about this map, available products associated with this FIRM including historic versions of this FIRM, how to order products, or the National Flood Insurance Program in general, please call the FEMA Map Information eXchange at 1-877- FEMA-MAP (1-877-336-2627) or visit the FEMA Flood Map Service Center website at msc.fema.gov . Available products may include previously issued Letters of Map Change, a Flood Insurance Study Report, and/or digital versions of this map. Many of these products can be ordered or obtained directly from the website. Users may determine the current map date for each FIRM panel by visiting the FEMA Flood Map Service Center website or by calling the FEMA Map Information eXchange.

Communities annexing land on adjacent FIRM panels must obtain a current copy of the adjacent panel as well as the current FIRM Index. These may be ordered directly from the Flood Map Service Center at the number listed above.

For community and countywide map dates, refer to Table 28 in this FIS Report.

To determine if flood insurance is available in the community, contact your insurance agent or call the National Flood Insurance Program at 1-800-638-6620.

PRELIMINARY FIS REPORT: FEMA maintains information about map features, such as street locations and names, in or near designated flood hazard areas. Requests to revise information in or near designated flood hazard areas may be provided to FEMA during the community review period, at the final Consultation Coordination Officer's meeting, or during the statutory 90-day appeal period. Approved requests for changes will be shown on the final printed FIRM.

The map is for use in administering the NFIP. It may not identify all areas subject to flooding, particularly from local drainage sources of small size. Consult the community map repository to find updated or additional flood hazard information.

BASE FLOOD ELEVATIONS: For more detailed information in areas where Base Flood Elevations (BFEs) and/or floodways have been determined, consult the Flood Profiles and Floodway Data and/or Summary of Non-Coastal Stillwater Elevations tables within this FIS Report. Use the flood elevation data within the FIS Report in conjunction with the FIRM for construction and/or floodplain management.

Coastal Base Flood Elevations shown on the map apply only landward of 0.0' North American Vertical Datum of 1988 (NAVD88). Coastal flood elevations are also provided in the Coastal Transect Parameters table in the FIS Report for this jurisdiction. Elevations shown in the Coastal Transect Parameters table should be used for construction and/or floodplain management purposes when they are higher than the elevations shown on the FIRM.

24 Figure 2. FIRM Notes to Users

FLOODWAY INFORMATION: Boundaries of the floodways were computed at cross sections and interpolated between cross sections. The floodways were based on hydraulic considerations with regard to requirements of the National Flood Insurance Program. Floodway widths and other pertinent floodway data are provided in the FIS Report for this jurisdiction. FLOOD CONTROL STRUCTURE INFORMATION: Certain areas not in Special Flood Hazard Areas may be protected by flood control structures. Refer to Section 4.3 "Non-Levee Flood Protection Measures" of this FIS Report for information on flood control structures for this jurisdiction. PROJECTION INFORMATION: The projection used in the preparation of the map was Universal Transverse Mercator (UTM) Zone 19N. The horizontal datum was the North American Datum of 1983 NAD83, GRS1980 spheroid . Differences in datum, spheroid, projection or State Plane zones used in the production of FIRMs for adjacent jurisdictions may result in slight positional differences in map features across jurisdiction boundaries. These differences do not affect the accuracy of the FIRM. ELEVATION DATUM: Flood elevations on the FIRM are referenced to the North American Vertical Datum of 1988. These flood elevations must be compared to structure and ground elevations referenced to the same vertical datum. For information regarding conversion between the National Geodetic Vertical Datum of 1929 and the North American Vertical Datum of 1988, visit the National Geodetic Survey website at www.ngs.noaa.gov. Local vertical monuments may have been used to create the map. To obtain current monument information, please contact the appropriate local community listed in Table 31 of this FIS Report. BASE MAP INFORMATION: Base map information shown on the FIRM was provided by MeGIS. High resolution orthophoto imagery was produced from 3-inch, 6-inch, and 2-foot pixel cells. Photography was captured during spring 2012 and produced at a scale of 1:600 on August 2012. For information about base maps, refer to Section 6.2 “Base Map” in this FIS Report. The map reflects more detailed and up-to-date stream channel configurations than those shown on the previous FIRM for this jurisdiction. The floodplains and floodways that were transferred from the previous FIRM may have been adjusted to conform to these new stream channel configurations. As a result, the Flood Profiles and Floodway Data tables may reflect stream channel distances that differ from what is shown on the map. Corporate limits shown on the map are based on the best data available at the time of publication. Because changes due to annexations or de-annexations may have occurred after the map was published, map users should contact appropriate community officials to verify current corporate limit locations.

NOTES FOR FIRM INDEX REVISIONS TO INDEX: As new studies are performed and FIRM panels are updated within York County, Maine, corresponding revisions to the FIRM Index will be incorporated within the FIS Report to reflect the effective dates of those panels. Please refer to Table 28 of this FIS Report to determine the most recent FIRM revision date for each community. The most recent FIRM panel effective date will correspond to the most recent index date.

25 Figure 2. FIRM Notes to Users

SPECIAL NOTES FOR SPECIFIC FIRM PANELS This Notes to Users section was created specifically for York County, Maine, effective Date [TBD].

COASTAL BARRIER RESOURCES SYSTEM (CBRS): This map includes approximate boundaries of the CBRS for informational purposes only. Flood insurance is not available within CBRS areas for structures that are newly built or substantially improved on or after the date(s) indicated on the map. For more information see www.fws.gov/cbra, the FIS Report, or call the U.S. Fish and Wildlife Service Customer Service Center at 1-800-344-WILD.

LIMIT OF MODERATE WAVE ACTION: Zone AE has been divided by a Limit of Moderate Wave Action (LiMWA). The LiMWA represents the approximate landward limit of the 1.5-foot breaking wave. The effects of wave hazards between Zone VE and the LiMWA (or between the shoreline and the LiMWA for areas where Zone VE is not identified) will be similar to, but less severe than, those in Zone VE.

STATE OF MAINE FLOODWAY NOTE: Under the Maine Revised Statutes Annotated (M.R.S.A) Title 38 § 439-A, 7C where the floodway is not designated on the Flood Insurance Rate Map, the floodway is considered to be the channel of a river or other water course and the adjacent land areas to a distance of one-half the width of the floodplain, as measured from the normal high water mark to the upland limit of the floodplain, unless a technical evaluation certified by a registered professional engineer is provided demonstrating the actual floodway based upon approved FEMA modeling methods.

COASTAL STRUCTURES: Only coastal structures that are certified to provide protection from the 1-percent-annual chance flood are shown on the panels. However, all structures taken into consideration for the purpose of coastal flood hazard analysis and mapping are present in the DFIRM database in S_Gen_Struct.

FLOOD RISK REPORT: A Flood Risk Report (FRR) may be available for many of the flooding sources and communities referenced in this FIS Report. The FRR is provided to increase public awareness of flood risk by helping communities identify the areas within their jurisdictions that have the greatest risks. Although non-regulatory, the information provided within the FRR can assist communities in assessing and evaluating mitigation opportunities to reduce these risks. It can also be used by communities developing or updating flood risk mitigation plans. These plans allow communities to identify and evaluate opportunities to reduce potential loss of life and property. However, the FRR is not intended to be the final authoritative source of all flood risk data for a project area; rather, it should be used with other data sources to paint a comprehensive picture of flood risk.

26

Each FIRM panel contains an abbreviated legend for the features shown on the maps. However, the FIRM panel does not contain enough space to show the legend for all map features. Figure 3 shows the full legend of all map features. Note that not all of these features may appear on the FIRM panels in York County.

Figure 3: Map Legend for FIRM

SPECIAL FLOOD HAZARD AREAS: The 1% annual chance flood, also known as the base flood or 100-year flood, has a 1% chance of happening or being exceeded each year. Special Flood Hazard Areas are subject to flooding by the 1% annual chance flood. The Base Flood Elevation is the water surface elevation of the 1% annual chance flood. The floodway is the channel of a stream plus any adjacent floodplain areas that must be kept free of encroachment so that the 1% annual chance flood can be carried without substantial increases in flood heights. See note for specific types. If the floodway is too narrow to be shown, a note is shown. Special Flood Hazard Areas subject to inundation by the 1% annual chance flood (Zones A, AE, AH, AO, AR, A99, V and VE)

Zone A The flood insurance rate zone that corresponds to the 1% annual chance floodplains. No base (1% annual chance) flood elevations (BFEs) or depths are shown within this zone. Zone AE The flood insurance rate zone that corresponds to the 1% annual chance floodplains. Base flood elevations derived from the hydraulic analyses are shown within this zone. Zone AH The flood insurance rate zone that corresponds to the areas of 1% annual chance shallow flooding (usually areas of ponding) where average depths are between 1 and 3 feet. Whole-foot BFEs derived from the hydraulic analyses are shown at selected intervals within this zone. Zone AO The flood insurance rate zone that corresponds to the areas of 1% annual chance shallow flooding (usually sheet flow on sloping terrain) where average depths are between 1 and 3 feet. Average whole-foot depths derived from the hydraulic analyses are shown within this zone. Zone AR The flood insurance rate zone that corresponds to areas that were formerly protected from the 1% annual chance flood by a flood control system that was subsequently decertified. Zone AR indicates that the former flood control system is being restored to provide protection from the 1% annual chance or greater flood. Zone A99 The flood insurance rate zone that corresponds to areas of the 1% annual chance floodplain that will be protected by a Federal flood protection system where construction has reached specified statutory milestones. No base flood elevations or flood depths are shown within this zone. Zone V The flood insurance rate zone that corresponds to the 1% annual chance coastal floodplains that have additional hazards associated with storm waves. Base flood elevations are not shown within this zone. Zone VE Zone VE is the flood insurance rate zone that corresponds to the 1% annual chance coastal floodplains that have additional hazards associated with storm waves. Base flood elevations derived from the coastal analyses are shown within this zone as static whole-foot elevations that apply throughout the zone.

27 Figure 3: Map Legend for FIRM

Regulatory Floodway determined in Zone AE.

Non-encroachment zone (see Section 2.4 of this FIS Report for more information) OTHER AREAS OF FLOOD HAZARD Shaded Zone X: Areas of 0.2% annual chance flood hazards and areas of 1% annual chance flood hazards with average depths of less than 1 foot or with drainage areas less than 1 square mile. Future Conditions 1% Annual Chance Flood Hazard – Zone X: The flood insurance rate zone that corresponds to the 1% annual chance floodplains that are determined based on future-conditions hydrology. No base flood elevations or flood depths are shown within this zone. Area with Reduced Flood Risk due to Levee: Areas where an accredited levee, dike, or other flood control structure has reduced the flood risk from the 1% annual chance flood. Area with Flood Risk due to Levee: Areas where a non-accredited levee, dike, or other flood control structure is shown as providing protection to less than the 1% annual chance flood. OTHER AREAS Zone D (Areas of Undetermined Flood Hazard): The flood insurance rate zone that corresponds to unstudied areas where flood hazards are undetermined, but possible. NO SCREEN Unshaded Zone X: Areas of minimal flood hazard.

FLOOD HAZARD AND OTHER BOUNDARY LINES

Flood Zone Boundary (white line on ortho-photography-based mapping; gray line on vector-based mapping) (ortho) (vector)

Limit of Study

Jurisdiction Boundary

Limit of Moderate Wave Action (LiMWA): Indicates the inland limit of the

area affected by waves greater than 1.5 feet

GENERAL STRUCTURES

Aqueduct Channel Channel, Culvert, Aqueduct, or Storm Sewer Culvert Storm Sewer

28 Figure 3: Map Legend for FIRM

______Dam Jetty Dam, Jetty, Weir Weir

Levee, Dike, or Floodwall

Bridge Bridge

COASTAL BARRIER RESOURCES SYSTEM (CBRS) AND OTHERWISE PROTECTED AREAS (OPA): CBRS areas and OPAs are normally located within or adjacent to Special Flood Hazard Areas.

Coastal Barrier Resources System Area: Labels are shown to clarify where this area shares a boundary with an incorporated area or overlaps with the floodway. CBRS AREA 09/30/2009

Otherwise Protected Area OTHERWISE PROTECTED AREA 09/30/2009

REFERENCE MARKERS

River mile Markers

CROSS SECTION & TRANSECT INFORMATION

Lettered Cross Section with Regulatory Water Surface Elevation (BFE)

Numbered Cross Section with Regulatory Water Surface Elevation (BFE)

Unlettered Cross Section with Regulatory Water Surface Elevation (BFE)

Coastal Transect

Profile Baseline: Indicates the modeled flow path of a stream and is shown on FIRM panels for all valid studies with profiles or otherwise established base flood elevation. Coastal Transect Baseline: Used in the coastal flood hazard model to represent the 0.0-foot elevation contour and the starting point for the transect and the measuring point for the coastal mapping.

Base Flood Elevation Line

29 Figure 3: Map Legend for FIRM

ZONE AE Static Base Flood Elevation value (shown under zone label) (EL 16) ZONE AO (DEPTH 2) Zone designation with Depth ZONE AO (DEPTH 2) Zone designation with Depth and Velocity (VEL 15 FPS) BASE MAP FEATURES Missouri Creek River, Stream or Other Hydrographic Feature

Interstate Highway

U.S. Highway

State Highway

County Highway

MAPLE LANE Street, Road, Avenue Name, or Private Drive if shown on Flood Profile

Railroad RAILROAD

Horizontal Reference Grid Line

Horizontal Reference Grid Ticks

Secondary Grid Crosshairs

Land Grant Name of Land Grant

7 Section Number

R. 43 W. T. 22 N. Range, Township Number

42 76 000m E Horizontal Reference Grid Coordinates (UTM)

365000 FT Horizontal Reference Grid Coordinates (State Plane)

80 °°° 16’ 52.5” Corner Coordinates (Latitude, Longitude)

30

SECTION 2.0 – FLOODPLAIN MANAGEMENT APPLICATIONS

2.1 Floodplain Boundaries To provide a national standard without regional discrimination, the 1% annual chance (100-year) flood has been adopted by FEMA as the base flood for floodplain management purposes. The 0.2% annual chance (500-year) flood is employed to indicate additional areas of flood hazard in the community.

Each flooding source included in the project scope has been studied and mapped using professional engineering and mapping methodologies that were agreed upon by FEMA and York County as appropriate to the risk level. Flood risk is evaluated based on factors such as known flood hazards and projected impact on the built environment. Engineering analyses were performed for each studied flooding source to calculate its 1% annual chance flood elevations; elevations corresponding to other floods (e.g. 10-, 4, 2-, 0.2-percent annual chance, etc.) may have also been computed for certain flooding sources. Engineering models and methods are described in detail in Section 5.0 of this FIS Report. The modeled elevations at cross sections were used to delineate the floodplain boundaries on the FIRM; between cross sections, the boundaries were interpolated using elevation data from various sources. More information on specific mapping methods is provided in Section 6.0 of this FIS Report.

Depending on the accuracy of available topographic data (Table 23), study methodologies employed (Section 5.0), and flood risk, certain flooding sources may be mapped to show both the 1% and 0.2% annual chance floodplain boundaries, regulatory water surface elevations (BFEs), and/or a regulatory floodway. Similarly, other flooding sources may be mapped to show only the 1% annual chance floodplain boundary on the FIRM, without published water surface elevations. In cases where the 1% and 0.2% annual chance floodplain boundaries are close together, only the 1% annual chance floodplain boundary is shown on the FIRM. Figure 3, “Map Legend for FIRM”, describes the flood zones that are used on the FIRMs to account for the varying levels of flood risk that exist along flooding sources within the project area. Table 2 and Table 3 indicate the flood zone designations for each flooding source and each community within York County, respectively.

Table 2, “Flooding Sources Included in this FIS Report,” lists each flooding source, including its study limits, affected communities, mapped zone on the FIRM, and the completion date of its engineering analysis from which the flood elevations on the FIRM and in the FIS Report were derived. Descriptions and dates for the latest hydrologic and hydraulic analyses of the flooding sources are shown in Table 13. Floodplain boundaries for these flooding sources are shown on the FIRM (published separately) using the symbology described in Figure 3. On the map, the 1% annual chance floodplain corresponds to the SFHAs. The 0.2% annual chance floodplain shows areas that, although out of the regulatory floodplain, are still subject to flood hazards.

Small areas within the floodplain boundaries may lie above the flood elevations but cannot be shown due to limitations of the map scale and/or lack of detailed topographic

31 data. The procedures to remove these areas from the SFHA are described in Section 6.5 of this FIS Report.

32

Table 2: Flooding Sources Included in this FIS Report Length (mi) Area (mi 2) Zone HUC-8 Sub- (streams or (estuaries Floodway shown Date of Flooding Source Community Downstream Limit Upstream Limit Basin(s) coastlines) or ponding) (Y/N) on FIRM Analysis Biddeford, Saco, Arundel, Eliot, Kennebunk, 01060001 VE, AE, Atlantic Ocean Kennebunkport, Entire Coastline Entire Coastline 01060002 271.00 N 2013 AO Kittery, Ogunquit, 01060003 Old Orchard Beach, Wells, York 1977 Acton, Town of; Entire shoreline Entire shoreline 01060002 0.44 N AE (redelineated Newfield, Town of 2013) Approximately 3,200 From the Dam just 1981 Kennebunkport, feet upstream of Stone Batson River downstream of State 01060003 1.38 Y AE (redelineated Town of Road in the Town of Route 9 2013) Kennebunkport. North Berwick, 1990 Bauneg Beg Town of; Sanford, Entire shoreline Entire shoreline 01060003 0.31 N AE (redelineated Pond City of 2013) From approximately Approximately 1,050 1978 5,800 feet upstream of Blacksmith Brook Wells, Town of feet upstream of U.S. 01060003 0.45 Y AE (redelineated the confluence with the Route 1 2013) Webhannet River 1979 Bonny Eagle Buxton, Town of Entire shoreline Entire shoreline 01060002 0.16 N AE (redelineated Pond Dam 2013) 1978 From Long Beach Approximately 1,725 ft Bridges Swamp York, Town of 01060003 0.64 Y AE (redelineated Avenue upstream of Ridge Road 2013) 1989 Bunganut Pond Lyman, Town of Entire shoreline Entire shoreline 01060003 0.47 N AE (redelineated 2013)

33 Table 2: Flooding Sources Included in this FIS Report • continued Length (mi) Area (mi 2) Zone HUC-8 Sub- (streams or (estuaries Floodway shown Date of Flooding Source Community Downstream Limit Upstream Limit Basin(s) coastlines) or ponding) (Y/N) on FIRM Analysis 1978 Cape Neddick Confluence of Tributary York, Town of Shore Road 01060003 1.48 Y AE (redelineated River 1 to Cape Neddick River 2013) From a point 750 feet Approximately 1,240 2010 Chickering Creek Kittery, Town of upstream of Dana feet upstream of Dana 01060003 0.09 N AE (redelineated Avenue Avenue 2013) 1978 Confluence with the Approximately 10,000 Cider Hill Creek York, Town of 01060003 1.82 Y AE (redelineated feet upstream 2013) Approximately 1,550 2007 From its confluence Coffin Brook Berwick, Town of feet upstream of Route 01060003 1.22 N AE (redelineated with Worster Brook 9 2013) Approximately 3,250 2007 Coffin Brook From its confluence Berwick, Town of feet upstream of Woods 01060003 1.43 N AE (redelineated Tributary 1 with Coffin Brook Road 2013) Approximately one mile 1979 Dayton, Town of; Cooks Brook From Dennett Dam upstream of State Route 01060002 3.99 Y AE (redelineated Hollis, Town of 5 2013) Approximately 4,600 1981 Kennebunk, Town From its confluence Day Brook feet upstream of Cat 01060003 1.16 Y AE (redelineated of with the Mousam River Mousam Road 2013) Approximately 850 feet Approximately 3,900 1978 Depot Brook Wells, Town of downstream of the feet upstream of the 01060003 0.87 Y AE, VE (redelineated concrete dam concrete dam 2013) Approximately 100 feet 1978 Dolly Gordon From its confluence York, Town of upstream of U.S. Route 01060003 1.56 Y AE (redelineated Brook with York River 1 2013) 2007 Just downstream of Just upstream of Driscoll Brook Berwick, Town of 01060003 2.34 N AE (redelineated railroad Blackberry Hill Road 2013) Within the City of Within the City of 1989 Alfred, Town of; Estes Lake Sanford and Town of Sanford and Town of 01060003 0.56 N AE (redelineated Sanford, City of Alfred Alfred 2013)

34 Table 2: Flooding Sources Included in this FIS Report • continued

Length (mi) Area (mi 2) Zone HUC-8 Sub- (streams or (estuaries Floodway shown Date of Flooding Source Community Downstream Limit Upstream Limit Basin(s) coastlines) or ponding) (Y/N) on FIRM Analysis Approximately 850 feet 2007 From its confluence Ferguson Brook Berwick, Town of upstream of Bromo 01060003 2.08 N AE (redelineated with the Worster Brook Road 2013) From a point 2,300 feet Approximately 5,250 2012 Fuller Brook Kittery, Town of upstream of Haley feet upstream of Haley 01060003 0.55 N AE (redelineated Road Road 2013) From its confluence Approximately 100 feet 1977 Goodall Brook Sanford, City of with the Great Works upstream of Berwick 01060003 0.68 Y AE (redelineated River Road 2013) From a point 10,350 Saco, City of; Old feet upstream of its Approximately 2,250 Goosefare Brook Orchard Beach, confluence with the feet upstream of Ross 01060001 2.51 Y AE 1978 Town of Atlantic Ocean Road upstream North Berwick, Approximately 100 feet 1977 Great Works At North Town of; Sanford, upstream of Twombley 01060003 6.60 Y AE (redelineated River Berwick/Sanford border City of Road 2013) South Berwick, From just upstream of At Sanford border about 1977 Great Works Town of; North its confluence with 2400 feet upstream of 01060003 20.80 Y AE (redelineated River Berwick, Town of Salmon Falls River Sand Pond Rd 2013) Approximately 600 feet upstream of its 1978 From its confluence Green Brook Wells, Town of confluence with 01060003 1.27 Y AE (redelineated with the Ogunquit River Tributary to Green 2013) Brook From a point 4,450 feet Approximately 7,950 2007 upstream of its feet upstream of its Hill Creek Kittery, Town of 01060003 0.69 N AE (redelineated confluence with Spruce confluence with Spruce 2013) Creek Creek Approximately 1,250 1979 From its confluence Josias River Ogunquit, Town of feet upstream of U.S. 01060003 1.02 Y AE (redelineated with the Basin Route 1 2013)

35 Table 2: Flooding Sources Included in this FIS Report • continued Length (mi) Area (mi 2) Zone HUC-8 Sub- (streams or (estuaries Floodway shown Date of Flooding Source Community Downstream Limit Upstream Limit Basin(s) coastlines) or ponding) (Y/N) on FIRM Analysis Upstream corporate limit From its confluence 2007 (approximately 8,300 Keay Brook Berwick, Town of with the Salmon Falls 01060003 4.19 N AE (redelineated feet upstream of Ridlon River 2013) Road) 1989 Kennebunk Pond Lyman, Town of Entire shoreline Entire shoreline 01060003 0.31 N AE (redelineated 2013) Along border of Kennebunk and Kennebunk, Town Kennebunkport. From Approximately 2,750 of; Kennebunkport, Kennebunk River approximately 500 feet feet upstream of U.S. 01060003 11.16 Y AE, VE 1981 Town of; Arundel, upstream of its Route 1 in Arundel Town of confluence with the Atlantic Ocean Lake of the Kennebunkport, Entire shoreline Entire shoreline 01060003 N/A N N/A 1978 Woods Town of Entire shoreline within Entire shoreline within the Town of Waterboro the Town of Waterboro 1977 Little Ossipee including the outlet including the outlet Waterboro, Town of 01060002 0.88 N AE (redelineated Lake stream to its stream to its confluence 2013) confluence with the with the Little Ossipee River To the Limington/Limerick/ 1979 Little Ossipee Limington, Town of; Confluence with Saco Waterboro Border 01060002 16.38 Y AE (redelineated River Waterboro, Town of River (approximately 600 feet 2013) downstream of New Dam Road in Limerick) From the Limerick, Town of; Limington/Limerick/ Waterboro, Town of; 1977 Little Ossipee Waterboro Border Confluence with Balch Newfield, Town of, 01060002 15.77 Y AE (redelineated River (approximately 600 feet Pond Dam Shapleigh, Town of; 2013) downstream of New Acton, Town of Dam Road in Limerick)

36 Table 2: Flooding Sources Included in this FIS Report • continued Length (mi) Area (mi 2) Zone HUC-8 Sub- (streams or (estuaries Floodway shown Date of Flooding Source Community Downstream Limit Upstream Limit Basin(s) coastlines) or ponding) (Y/N) on FIRM Analysis From approximately Approximately 2,380 Kennebunkport, 1978 650 feet upstream of its feet upstream of Oak Little River Town of; Biddeford, 01060003 3.62 Y AE (redelineated confluence with the Ridge Road in the City City of 2013) Atlantic Ocean of Biddeford Upstream corporate limit 2007 Little River (Town Confluence with (approximately 18,300 Berwick, Town of 01060003 8.59 N AE (redelineated of Berwick) Salmon Falls River feet upstream of 2013) Diamond Hill Road) 1978 Little River (Town Confluence with the Cornish, Town of State Routes 5 and 117 01060002 1.21 Y AE (redelineated of Cornish) Ossipee River 2013) Along border of Kennebunk and Wells. Along border of 1978 Little River (Town Kennebunk, Town Approximately 1,000 Kennebunk and Wells. 01060003 1.33 Y AE, VE (redelineated of Kennebunk) of; Wells, Town of feet upstream of its Confluence with Branch 2013) confluence with the Brook Atlantic Ocean Approximately 1.8 miles From Estes Lake Dam Alfred, Town of; upstream of U.S. Route Littlefield River along border of Alfred 01060003 7.46 N AE 1989 Sanford, City of 202 and State Route 4 and Sanford in the Town of Alfred Approximately 2,900 1978 Merriland River From its confluence Wells, Town of feet upstream of U.S. 01060003 2.08 Y AE, VE (redelineated (Lower Reach) with the Little River Route 1 2013) The dam just 1978 Merriland River Approximately 2.1 miles Wells, Town of downstream of Hobbs 01060003 2.04 Y AE (redelineated (Upper Reach) upstream Farm Road 2013) From approximately 2001 Middle Branch 3,000 feet upstream of State Route 4/State Alfred, Town of 01060003 0.65 N AE (redelineated Mousam River confluence with Estes Route 202 2013) Lake

37 Table 2: Flooding Sources Included in this FIS Report • continued Length (mi) Area (mi 2) Zone HUC-8 Sub- (streams or (estuaries Floodway shown Date of Flooding Source Community Downstream Limit Upstream Limit Basin(s) coastlines) or ponding) (Y/N) on FIRM Analysis For the entire length Old Orchard Beach, within the community Approximately 1.2 miles Mill Brook 01060001 1.25 Y AE 1978 Town of of Old Orchard Beach, upstream from Ross Road 1978 From Meetinghouse Approximately 1.55 Moors Brook Biddeford, City of 01060002 1.58 Y AE (redelineated Road in Biddeford miles upstream 2013) To the upstream corporate limits 1990 Mousam River From its confluence approximately 1,000 feet Sanford, City of 01060003 11.99 Y AE (redelineated (City of Sanford) with Estes Lake upstrea m of State Route 2013) 109 in the City of Sanford From the Kennebunk- Mousam River Aflred, Town of; Sanford corporate Estes Lake Dam 01060003 1.47 Y AE 1995 (Lower Reach) Sanford, City of limits From a point approximately 2,000 ft Mousam River Kennebunk, Town downstream from the Approximately 500 feet (Town of 01060003 8.27 Y AE, VE 2008 of bridge/dam upstream of Mill Street Kennebunk) combination at US Route 1 2007 From its confluence Approximately 1.3 miles Mulloy Brook Berwick, Town of 01060003 1.29 N AE (redelineated with Worster Brook upstream 2013) Ogunquit, Town of; Confluence with Green Ogunquit River From Beach Street 01060003 5.10 Y AE 1979 Wells, Town of Brook 1979 Ogunquit River From its confluence Approximately 2,950 Ogunquit, Town of 01060003 0.57 Y AE (redelineated Tributary with the Ogunquit River feet upstream 2013)

38 Table 2: Flooding Sources Included in this FIS Report • continued

Length (mi) Area (mi 2) Zone HUC-8 Sub- (streams or (estuaries Floodway shown Date of Flooding Source Community Downstream Limit Upstream Limit Basin(s) coastlines) or ponding) (Y/N) on FIRM Analysis Approximately 2.06 Cornish, Town of; miles upstream of the Ossipee River Parsonsfield, Town Border of Cornish 01060002 13.60 Y AE 1978 confluence of South of River 1987 Entire length within Entire length within Eliot, Eliot, Town of 01060003 10.00 N AE (redelineated Eliot, Town of Town of 2013) 2006 Ponding Area 1 Alfred, Town of Entire shoreline Entire shoreline 01060003 0.00 N AH (redelineated 2013) 2006 Alfred, Town of; Ponding Area 2 Entire shoreline Entire shoreline 01060003 0.02 N AH (redelineated Lyman, Town of 2013) 2006 Ponding Area 3 Alfred, Town of Entire shoreline Entire shoreline 01060003 0.00 N AH (redelineated 2013) 1989 Roberts-Wadley Lyman, Town of Entire shoreline Entire shoreline 01060002 0.47 N AE (redelineated Pond 2013) From West Branch Saco-Buxton-Dayton Saco River Saco, City of 01060002 4.61 Y AE 1982 Dam border Dayton, Town of; Buxton, Town of; Biddeford/Dayton/Saco Limington and Cornish Saco River 01060002 31.50 Y AE 1979 Hollis, Town of; Border border Limington, Town of From West Branch Biddeford-Dayton-Saco Saco River Biddeford, City of 01060002 3.40 Y AE 1978 Dam border Limington and Approximately 2.6 Miles Saco River Cornish, Town of Cumberland County 01060002 1.84 Y AE 1978 from Hussey Hill Road border Town of Buxton 1979 Saco River - Left From its confluence Buxton, Town of upstream corporate 01060002 0.56 N AE (redelineated Channel with the Saco River limits 2013)

39 Table 2: Flooding Sources Included in this FIS Report • continued Length (mi) Area (mi 2) Zone HUC-8 Sub- (streams or (estuaries Floodway shown Date of Flooding Source Community Downstream Limit Upstream Limit Basin(s) coastlines) or ponding) (Y/N) on FIRM Analysis From a point 1991 Salmon Falls approximately 3,050 Berwick, Town of Border of Lebanon 01060003 11.39 Y AE (redelineated River feet downstream of 2013) New Dam Road 1985 Salmon Falls Lebanon, Town of; Berwick border Acton Border 01060003 22.28 Y AE (redelineated River Acton, Town of 2013) Approximately 50 feet 1982 Sawyer Brook Saco, City of From Sawyer Street upstream of Therrien 01060002 0.54 N AE (redelineated Avenue 2013) 1989 Shaker Pond Alfred, Town of Entire shoreline Entire shoreline 01060003 0.17 N AE (redelineated 2013) 1981 Kennebunkport, Approximately 1,225 Smith Brook From State Route 9 01060003 0.24 Y AE (redelineated Town of feet upstream 2013) 1978 South Branch of From its confluence Approximately 2,225 Wells, Town of 01060003 0.42 Y AE (redelineated West Brook with West Brook feet upstream 2013) On Elliot and Kittery On Elliot and Kittery border. From border. Approximately 1987 approximately 5,300 Spinney Creek Eliot, Town of 350 feet upstream of 01060003 0.12 Y AE (redelineated feet upstream of its Dennett Road in the 2013) confluence with the Town of Eliot. Piscataqua River On Elliot and Kittery On Elliot and Kittery border. From border. Approximately 1982 approximately 5,300 Spinney Creek Kittery, Town of 350 feet upstream of 01060003 0.12 Y AE (redelineated feet upstream of its Dennett Road in the 2013) confluence with the Town of Eliot. Piscataqua River

40 Table 2: Flooding Sources Included in this FIS Report • continued Length (mi) Area (mi 2) Zone HUC-8 Sub- (streams or (estuaries Floodway shown Date of Flooding Source Community Downstream Limit Upstream Limit Basin(s) coastlines) or ponding) (Y/N) on FIRM Analysis From just downstream 1982 Approximately 2,100 Spruce Creek Kittery, Town of of Wilson Road (State 01060003 0.41 Y AE (redelineated feet upstream Route 101) 2013) From approximately 2 Approximately 2,000 1978 miles upstream of its feet upstream of U.S. Stevens Brook Wells, Town of 01060003 0.98 Y AE (redelineated confluence with Route 1 in the Town of 2013) Ogunquit River Wells. 1989 Swan Pond Lyman, Town of Entire shoreline Entire shoreline 01060002 0.17 N AE (redelineated 2013) Approximately 2,350 1978 From its confluence Thatcher Brook Biddeford, City of feet upstream of South 01060002 1.27 Y AE (redelineated with the Saco River Street 2013) Tributary 1 to From its confluence Approximately 1,450 1978 Cape Neddick York, Town of with Cape Neddick feet upstream of 01060003 0.57 Y AE (redelineated River River Mountain Road 2013) Approximately 1,400 1978 Tributary 1 to From its confluence Wells, Town of feet upstream of Hiltons 01060003 0.63 Y AE (redelineated Green Brook with Green Brook Lane 2013) Tributary to From approximately Approximately 2,800 1995 Middle Branch Alfred, Town of 200 feet downstream of feet upstream of Middle 01060003 0.54 N AE (redelineated Mousam River Middle Branch Drive Branch Drive 2013) From a point Unnamed Approximately 3,650 2010 approximately 850 feet Tributary to Stony Hollis, Town of feet upstream of 01060002 0.59 N AE (redelineated upstream of Burnham Brook Burnham Lane 2013) Lane From approximately Approximately 2,950 3,800 feet downstream 1978 feet upstream of U.S. Webhannet River Wells, Town of of U.S. Route 4 (Blue 01060003 1.27 Y AE, VE (redelineated Route 4 (Blue Star Star Memorial 2013) Memorial Highway) Highway)

41 Table 2: Flooding Sources Included in this FIS Report • continued

Length (mi) Area (mi 2) Zone HUC-8 Sub- (streams or (estuaries Floodway shown Date of Flooding Source Community Downstream Limit Upstream Limit Basin(s) coastlines) or ponding) (Y/N) on FIRM Analysis Approximately 3,200 From approximately feet upstream of 1978 11,000 feet upstream West Brook Wells, Town of confluence with the 01060003 1.34 Y AE (redelineated of its confluence with South Branch of West 2013) Great Works River Brook From its confluence Approximately 5,900 2007 Worster Brook Berwick, Town of with the Salmon Falls feet upstream of Brown 01060003 6.99 N AE (redelineated River Road 2013) Approximately 150 feet 2007 Worster Brook From its confluence Berwick, Town of upstream of Thompson 01060003 1.21 N AE (redelineated Tributary 3 with Worster Brook Hill Road 2013) Numerous Unnamed 01060001 Tributaries or Refer to FIRM Refer to FIRM Refer to FIRM 01060002 N A 2012 / 2013 Local Ponding 01060003 Areas

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2.2 Floodways Encroachment on floodplains, such as structures and fill, reduces flood-carrying capacity, increases flood heights and velocities, and increases flood hazards in areas beyond the encroachment itself. One aspect of floodplain management involves balancing the economic gain from floodplain development against the resulting increase in flood hazard.

For purposes of the NFIP, a floodway is used as a tool to assist local communities in balancing floodplain development against increasing flood hazard. With this approach, the area of the 1% annual chance floodplain on a river is divided into a floodway and a floodway fringe based on hydraulic modeling. The floodway is the channel of a stream, plus any adjacent floodplain areas, that must be kept free of encroachment in order to carry the 1% annual chance flood. The floodway fringe is the area between the floodway and the 1% annual chance floodplain boundaries where encroachment is permitted. The floodway must be wide enough so that the floodway fringe could be completely obstructed without increasing the water surface elevation of the 1% annual chance flood more than 1 foot at any point. Typical relationships between the floodway and the floodway fringe and their significance to floodplain development are shown in Figure 4.

To participate in the NFIP, Federal regulations require communities to limit increases caused by encroachment to 1.0 foot, provided that hazardous velocities are not produced. The floodways in this project are presented to local agencies as minimum standards that can be adopted directly or that can be used as a basis for additional floodway projects.

Figure 4: Floodway Schematic

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Floodway widths presented in this FIS Report and on the FIRM were computed at cross sections. Between cross sections, the floodway boundaries were interpolated. For certain stream segments, floodways were adjusted so that the amount of floodwaters conveyed on each side of the floodplain would be reduced equally. The results of the floodway computations have been tabulated for selected cross sections and are shown in Table 24, “Floodway Data.”

All floodways that were developed for this Flood Risk Project are shown on the FIRM using the symbology described in Figure 3. In cases where the floodway and l% annual chance floodplain boundaries are either close together or collinear, only the floodway boundary has been shown on the FIRM. For information about the delineation of floodways on the FIRM, refer to Section 6.3.

2.3 Base Flood Elevations The hydraulic characteristics of flooding sources were analyzed to provide estimates of the elevations of floods of the selected recurrence intervals. The Base Flood Elevation (BFE) is the elevation of the 1% annual chance flood. These BFEs are most commonly rounded to the whole foot, as shown on the FIRM, but in certain circumstances or locations they may be rounded to 0.1 foot. Cross section lines shown on the FIRM may also be labeled with the BFE rounded to 0.1 foot. Whole-foot BFEs derived from engineering analyses that apply to coastal areas, areas of ponding, or other static areas with little elevation change may also be shown at selected intervals on the FIRM.

Cross sections with BFEs shown on the FIRM correspond to the cross sections shown in the Floodway Data table and Flood Profiles in this FIS Report. BFEs are primarily intended for flood insurance rating purposes. For construction and/or floodplain management purposes, users are cautioned to use the flood elevation data presented in this FIS Report in conjunction with the data shown on the FIRM.

2.4 Non-Encroachment Zones Some States and communities use non-encroachment zones to manage floodplain development. For flooding sources with medium flood risk, field surveys are often not collected and surveyed bridge and culvert geometry is not developed. Standard hydrologic and hydraulic analyses are still performed to determine BFEs in these areas. However, floodways are not typically determined, since specific channel profiles are not developed. To assist communities with managing floodplain development in these areas, a “non-encroachment zone” may be provided. While not a FEMA designated floodway, the non-encroachment zone represents that area around the stream that should be reserved to convey the 1% annual chance flood event. As with a floodway, all surcharges must fall within the acceptable range in the non-encroachment zone.

General setbacks can be used in areas of lower risk (e.g. unnumbered Zone A), but these are not considered sufficient where unnumbered Zone A is replaced by Zone AE. The NFIP requires communities to ensure that any development in a non-encroachment area causes no increase in BFEs. Communities must generally prohibit development within the area defined by the non-encroachment width to meet the NFIP requirement.

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2.5 Coastal Flood Hazard Areas For most areas along rivers, streams, and small lakes, BFEs and floodplain boundaries are based on the amount of water expected to enter the area during a 1% annual chance flood and the geometry of the floodplain. Floods in these areas are typically caused by storm events. However, for areas on or near ocean coasts, large rivers, or large bodies of water, BFE and floodplain boundaries may need to be based on additional components, including storm surges and waves. Communities on or near ocean coasts face flood hazards caused by offshore seismic events as well as storm events.

Coastal flooding sources that are included in this Flood Risk Project are shown in Table 2.

2.5.1 Water Elevations and the Effects of Waves Specific terminology is used in coastal analyses to indicate which components have been included in evaluating flood hazards.

The stillwater elevation (SWEL or still water level) is the surface of the water resulting from astronomical tides, storm surge, and freshwater inputs, but excluding wave setup contribution or the effects of waves. • Astronomical tides are periodic rises and falls in large bodies of water caused by the rotation of the earth and by the gravitational forces exerted by the earth, moon and sun. • Storm surge is the additional water depth that occurs during large storm events. These events can bring air pressure changes and strong winds that force water up against the shore. • Freshwater inputs include rainfall that falls directly on the body of water, runoff from surfaces and overland flow, and inputs from rivers.

The 1% annual chance stillwater elevation is the stillwater elevation that has been calculated for a storm surge from a 1% annual chance storm. The 1% annual chance storm surge can be determined from analyses of tidal gage records, statistical study of regional historical storms, or other modeling approaches. Stillwater elevations for storms of other frequencies can be developed using similar approaches.

The total stillwater elevation (also referred to as the mean water level) is the stillwater elevation plus wave setup contribution but excluding the effects of waves. • Wave setup is the increase in stillwater elevation at the shoreline caused by the reduction of waves in shallow water. It occurs as breaking wave momentum is transferred to the water column.

Like the stillwater elevation, the total stillwater elevation is based on a storm of a particular frequency, such as the 1% annual chance storm. Wave setup is typically estimated using standard engineering practices or calculated using models, since tidal gages are often sited in areas sheltered from wave action and do not capture this information.

Coastal analyses may examine the effects of overland waves by analyzing storm- induced erosion, overland wave propagation, wave runup, and/or wave overtopping.

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• Storm-induced erosion is the modification of existing topography by erosion caused by a specific storm event, as opposed to general erosion that occurs at a more constant rate. • Overland wave propagation describes the combined effects of variation in ground elevation, vegetation, and physical features on wave characteristics as waves move onshore. • Wave runup is the uprush of water from wave action on a shore barrier. It is a function of the roughness and geometry of the shoreline at the point where the stillwater elevation intersects the land. • Wave overtopping refers to wave runup that occurs when waves pass over the crest of a barrier.

Figure 5: Wave Runup Transect Schematic

2.5.2 Floodplain Boundaries and BFEs for Coastal Areas For coastal communities along the Atlantic and Pacific Oceans, the Gulf of Mexico, the Great Lakes, and the Caribbean Sea, flood hazards must take into account how storm surges, waves, and extreme tides interact with factors such as topography and vegetation. Storm surge and waves must also be considered in assessing flood risk for certain communities on rivers or large inland bodies of water.

Beyond areas that are affected by waves and tides, coastal communities can also have riverine floodplains with designated floodways, as described in previous sections.

Floodplain Boundaries In many coastal areas, storm surge is the principle component of flooding. The extent of the 1% annual chance floodplain in these areas is derived from the total stillwater elevation (stillwater elevation including storm surge plus wave setup) for the 1% annual chance storm. The methods that were used for calculation of total stillwater elevations for coastal areas are described in Section 5.3 of this FIS Report. Location of total stillwater elevations for coastal areas are shown in Figure 8, “1% Annual Chance Total Stillwater Levels for Coastal Areas.”

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In some areas, the 1% annual chance floodplain is determined based on the limit of wave runup or wave overtopping for the 1% annual chance storm surge. The methods that were used for calculation of wave hazards are described in Section 5.3 of this FIS Report.

Table 26 presents the types of coastal analyses that were used in mapping the 1% annual chance floodplain in coastal areas.

Coastal BFEs Coastal BFEs are calculated as the total stillwater elevation (stillwater elevation including storm surge plus wave setup) for the 1% annual chance storm plus the additional flood hazard from overland wave effects (storm-induced erosion, overland wave propagation, wave runup and wave overtopping).

Where they apply, coastal BFEs are calculated along transects extending from offshore to the limit of coastal flooding onshore. Results of these analyses are accurate until local topography, vegetation, or development type and density within the community undergoes major changes.

Parameters that were included in calculating coastal BFEs for each transect included in this FIS Report are presented in Table 17, “Coastal Transect Parameters.” The locations of transects are shown in Figure 9, “Transect Location Map.” More detailed information about the methods used in coastal analyses and the results of intermediate steps in the coastal analyses are presented in Section 5.3 of this FIS Report. Additional information on specific mapping methods is provided in Section 6.4 of this FIS Report.

2.5.3 Coastal High Hazard Areas Certain areas along the open coast and other areas may have higher risk of experiencing structural damage caused by wave action and/or high-velocity water during the 1% annual chance flood. These areas will be identified on the FIRM as Coastal High Hazard Areas.

• Coastal High Hazard Area (CHHA) is a SFHA extending from offshore to the inland limit of the primary frontal dune (PFD) or any other area subject to damages caused by wave action and/or high-velocity water during the 1% annual chance flood. • Primary Frontal Dune (PFD) is a continuous or nearly continuous mound or ridge of sand with relatively steep slopes immediately landward and adjacent to the beach. The PFD is subject to erosion and overtopping from high tides and waves during major coastal storms.

CHHAs are designated as “V” zones (for “velocity wave zones”) and are subject to more stringent regulatory requirements and a different flood insurance rate structure. The areas of greatest risk are shown as VE on the FIRM. Zone VE is further subdivided into elevation zones and shown with BFEs on the FIRM.

The landward limit of the PFD occurs at a point where there is a distinct change from a relatively steep slope to a relatively mild slope; this point represents the landward extension of Zone VE. Areas of lower risk in the CHHA are designated with Zone V on

47 the FIRM. More detailed information about the identification and designation of Zone VE is presented in Section 6.4 of this FIS Report.

Areas that are not within the CHHA but are SFHAs may still be impacted by coastal flooding and damaging waves; these areas are shown as “A” zones on the FIRM.

Figure 6, “Coastal Transect Schematic,” illustrates the relationship between the base flood elevation, the 1% annual chance stillwater elevation, and the ground profile as well as the location of the Zone VE and Zone AE areas in an area without a PFD subject to overland wave propagation. This figure also illustrates energy dissipation and regeneration of a wave as it moves inland.

Figure 6: Coastal Transect Schematic

Methods used in coastal analyses in this Flood Risk Project are presented in Section 5.3 and mapping methods are provided in Section 6.4 of this FIS Report.

Coastal floodplains are shown on the FIRM using the symbology described in Figure 3, “Map Legend for FIRM.” In many cases, the BFE on the FIRM is higher than the stillwater elevations shown in Table 17 due to the presence of wave effects. The higher elevation should be used for construction and/or floodplain management purposes.

2.5.4 Limit of Moderate Wave Action Laboratory tests and field investigations have shown that wave heights as little as 1.5 feet can cause damage to and failure of typical Zone AE building construction. Wood- frame, light gage steel, or masonry walls on shallow footings or slabs are subject to damage when exposed to waves less than 3 feet in height. Other flood hazards associated with coastal waves (floating debris, high velocity flow, erosion, and scour) can also damage Zone AE construction.

Therefore, a LiMWA boundary may be shown on the FIRM as an informational layer to assist coastal communities in safe rebuilding practices. The LiMWA represents the

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approximate landward limit of the 1.5-foot breaking wave. The location of the LiMWA relative to Zone VE and Zone AE is shown in Figure 6.

The effects of wave hazards in Zone AE between Zone VE (or the shoreline where Zone VE is not identified) and the limit of the LiMWA boundary are similar to, but less severe than, those in Zone VE where 3-foot or greater breaking waves are projected to occur during the 1% annual chance flooding event. Communities are therefore encouraged to adopt and enforce more stringent floodplain management requirements than the minimum NFIP requirements in the LiMWA. The NFIP Community Rating System provides credits for these actions.

Where wave runup elevations dominate over wave heights, there is no evidence to date of significant damage to residential structures by runup depths less than 3 feet. Examples of these areas include areas with steeply sloped beaches, bluffs, or flood protection structures that lie parallel to the shore. In these areas, the FIRM shows the LiMWA immediately landward of the VE/AE boundary. Similarly, in areas where the zone VE designation is based on the presence of a primary frontal dune or wave overtopping, the LiMWA is delineated immediately landward of the Zone VE/AE boundary.

SECTION 3.0 – INSURANCE APPLICATIONS

3.1 National Flood Insurance Program Insurance Zones For flood insurance applications, the FIRM designates flood insurance rate zones as described in Figure 3, “Map Legend for FIRM.” Flood insurance zone designations are assigned to flooding sources based on the results of the hydraulic or coastal analyses. Insurance agents use the zones shown on the FIRM and depths and base flood elevations in this FIS Report in conjunction with information on structures and their contents to assign premium rates for flood insurance policies.

The 1% annual chance floodplain boundary corresponds to the boundary of the areas of special flood hazards (e.g. Zones A, AE, V, VE, etc.), and the 0.2% annual chance floodplain boundary corresponds to the boundary of areas of additional flood hazards.

Table 3 lists the flood insurance zones in York County.

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Table 3: Flood Zone Designations by Community

Community Flood Zone(s) Acton, Town of A, AE, X Alfred, Town of A, AE, AH, X Arundel, Town of A, AE, X Berwick, Town of A, AE, X Biddeford, City of A, AE, VE, X Buxton, Town of A, AE, X Cornish, Town of A, AE, X Dayton, Town of A, AE, X Eliot, Town of A, AE, X Hollis, Town of A, AE, X Kennebunk, Town of A, AE, VE, X Kennebunkport, Town of A, AE, VE, X Kittery, Town of A, AE, VE, X Lebanon, Town of A, AE, X Limerick, Town of A, AE, X Limington, Town of A, AE, X Lyman, Town of A, AE, AH, X Newfield, Town of A, AE, X North Berwick, Town of A, AE, X Ogunquit, Town of A, AE, VE, X Old Orchard Beach, Town of A, AE, VE, X Parsonsfield, Town of A, AE, X Saco, City of A, AE, VE, X Sanford, City of A, AE, X Shapleigh, Town of A, AE, X South Berwick, Town of A, AE, X Waterboro, Town of A, AE, X Wells, Town of A, AE, VE, X York, Town of A, AE, AO, VE, X

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3.2 Coastal Barrier Resources System The Coastal Barrier Resources Act (CBRA) of 1982 was established by Congress to create areas along the Atlantic and Gulf coasts and the Great Lakes, where restrictions for Federal financial assistance including flood insurance are prohibited. In 1990, Congress passed the Coastal Barrier Improvement Act (CBIA), which increased the extent of areas established by the CBRA and added “Otherwise Protected Areas” (OPA) to the system. These areas are collectively referred to as the John. H Chafee Coastal Barrier Resources System (CBRS). The CBRS boundaries that have been identified in the project area are in Table 4, “Coastal Barrier Resource System Information.”

Table 4: Coastal Barrier Resources System Information

Primary Flooding CBRS/OPA Date CBRS Area Source Type Established FIRM Panel Number(s) 23031C0588G 23031C0589G Atlantic Ocean OPA 11/16/1991 23031C0676G 23031C0677G 23031C0581G 23031C0582G 23031C0583G Atlantic Ocean CBRS 11/16/1990 23031C0584G 23031C0679G 23031C0733G 23031C0582G 23031C0583G Atlantic Ocean CBRS 10/1/1983 23031C0584G 23031C0733G 23031C0734G

SECTION 4.0 – AREA STUDIED

4.1 Basin Description Table 5 contains a description of the characteristics of the HUC-8 sub-basins within which each community falls. The table includes the main flooding sources within each basin, a brief description of the basin, and its drainage area.

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Table 5: Basin Characteristics

Drainage HUC-8 Primary Area HUC-8 Sub- Sub-Basin Flooding (square Basin Name Number Source Description of Affected Area miles) Covers 20 towns in the southern Piscataqua- Piscataqua- portion of the county, the Mousam 01060003 Salmon Falls 1,692 Salmon Falls Salmon Falls Rivers and it's Rivers tributaries. This watershed includes 17 towns in the north and northeast section Saco 01060002 Saco River 1,701 of York County, covering the Saco river and it's tributaries. Includes portions of the towns on the Northeast edge of York Presumpscot Presumpscot 01060001 County, Biddeford, Saco, Buxton, 1,424 River Limington and Old Orchard Beach.

4.2 Principal Flood Problems Table 6 contains a description of the principal flood problems that have been noted for York County by flooding source.

Table 6: Principal Flood Problems

Flooding Source Description of Flood Problems Atlantic Ocean Coastal flooding in York County occurs due to coastal storms and hurricanes. and York Northeasters and southeasters are most frequent but more prevalent in winter County months. Hurricanes are less frequent but occur in late summer and early fall. coastline Hurricanes rarely produce significant storm surge north of Cape Cod, MA and are smaller, more intense storms that move rapidly in northern latitudes and lose strength quickly upon landfall.

Northeaster type storms represent low pressure systems that have developed off the southern Atlantic coast that travel northward along the coast collecting moisture and gathering strength during travel. Northeaster storms may be hundreds of miles in diameter and may travel slowly enough to produce heavy sustained onshore winds for as long as 48 hours. Northeasters often last through one or more tidal cycles. The combination of sustained onshore winds and high tide causes significant elevation of the water surface known as a storm surge. The worst storm surges occur in Hancock County when the winds are from the southeast quadrant.

Coastal shoreline erosion is a major concern throughout the county as is damage to low coastal roads, boats, beaches and seawalls. Occasional strong onshore winds and high tides result in tidal surge and wave activity that cause extensive property damage and erosion.

52 Table 6: Principal Flood Problems • continued Flooding Source Description of Flood Problems Flooding occurs almost annually along the Great Works River, affecting the towns of North Berwick, South Berwick, and the City of Sanford.

Great Works Most of the floods are caused by rapid thawing of snow and ice in late winter River and early spring, and the flooding is often accelerated by rainfall and ice jams. Less often, flooding occurs later in the year as a result of hurricanes.

Minor flooding occurs almost annually. In the Town of Ogunquit, some riverine flooding has occurred on the non-tidal portions of the Josias and Ogunquit Rivers. Most of the floodplains are underdeveloped and damage is limited during flooding. However, ice jamming Josias River occurs on the Josias River upstream of the U. S. Route 1 Bridge. In the Town of Wells, the only riverine flooding occurs infrequently on a small portion of U.S. Route 1 near the Merriland River (Reference 21).

Minor flooding occurs almost annually due to snowmelt and ice jams on the Little Ossipee River. Areas flooded include wooded and open lowlands, roads, and bridges. The flood of record occurred in March 1936 this flood was Little Ossipee generated from about 4 inches of rain over a two day period and further River complicated by high antecedent moisture conditions, snow cover, and ice laden streams. Numerous low-lying areas along the Little Ossipee River are subject to frequent flooding. Flooding of these areas can cause damage to dwellings, existing woodlands, roads, and bridges. The most severe flooding occurs in the early spring as a result of snowmelt and heavy rain in conjunction with ice jams. Additional floods generally lower in Little River magnitude also occur in late summer as a result of hurricanes and tropical storms. Flooding generally occurs in the spring from rapid runoff caused by heavy rains combined with snowmelt. Less frequently, flooding occurs later in the Littlefield River year as a result of hurricanes. Significant flooding has occurred 1977, 1983, and 1984. These floods had recurrence intervals of 2-, 1-, 3-percent-annual- chance, respectively. Merriland In the Town of Wells, the only riverine flooding occurs infrequently on a small River (Lower portion of U.S. Route 1 near the Merriland River (Reference 21). Reach) In the City of Sanford, the flood of March 1983 produced maximum flows of Mousam River 4,020 cubic feet per second (cfs) at the USGS gage on the Mousam River (City of near West Kennebunk and had a recurrence interval of approximately 85 years Sanford) (Reference 16). No records of flood damages to the town are available. In the Town of Ogunquit, some riverine flooding has occurred on the non-tidal Ogunquit portions of the Josias and Ogunquit Rivers. Most of the floodplains are River underdeveloped and damage is limited during flooding.

53 Table 6: Principal Flood Problems • continued Flooding Source Description of Flood Problems In the Town of Berwick, the March 1936 flood on the Salmon Falls River had an approximate recurrence interval of 2-percent-annual-chance. This flood washed out the Eddy Bridge, the Worster Bridge at New Dam, and Rochester Road.

Salmon Falls The most severe floods in the Town of Lebanon occur in early spring as a River result of snowmelt and heavy rains. In the past, ice jams have helped to cause high-water conditions, but, they have not caused a major flood problem in Lebanon.

The dams on the Salmon Falls River are recreational.

Table 7 contains information about historic flood elevations in the communities within York County.

Table 7: Historic Flooding Elevations [Not Applicable to this Flood Risk Project]

4.3 Non-Levee Flood Protection Measures Table 8 contains information about non-levee flood protection measures within York County such as dams, jetties, and or dikes. Levees are addressed in Section 4.4 of this FIS Report.

Table 8: Non-Levee Flood Protection Measures

Type of Description Flooding Source Structure Name Measure Location of Measure Atlantic Ocean Seawall Various Locations N/A North Berwick Great Works River Dam Town of North Berwick N/A Dam Keay Brook N/A Culvert Town of Berwick N/A Little Ossipee Little Dam Town of Waterboro N/A Lake Dam Balch Pond Little Ossipee River Dam Town of Acton N/A Dam Balch Pond Little Ossipee River Dam Town of Newfield N/A Dam Little Ossipee River Drop Structure Drop Structure Town of Newfield N/A Little Ossipee Little Ossipee River Dam Town of Limerick N/A Flowage Dam Little Ossipee Little Ossipee River Dam Town of Waterboro N/A Flowage Dam

54 Table 8: Non•Levee Flood Protection Measures • continued Type of Description Flooding Source Structure Name Measure Location of Measure 0.2% Annual Chance Flood Little Ossipee River N/A Discharge Town of Newfield N/A Contained In Structure 1% Annual Chance Flood Little Ossipee River N/A Discharge Town of Newfield N/A Contained In Structure Shapleigh Pond Little Ossipee River Dam Town of Newfield N/A Dam Shapleigh Pond Little Ossipee River Dam Town of Shapleigh N/A Dam Little River (Town Old Mill Dam Dam Town of Cornish N/A of Cornish) Littlefield River Alfred Mills Dam Dam Town of Alfred N/A Merriland River Breached Dam Dam Town of Wells N/A (Lower Reach) Merriland River N/A Dam Town of Wells N/A (Upper Reach) Mousam River (City Indian Ledge Dam City of Sanford N/A of Sanford) Drive Dam Mousam River (City Mousam Dam Dam City of Sanford N/A of Sanford) Mousam River (City N/A Culvert City of Sanford N/A of Sanford) Mousam River (City N/A Dam City of Sanford N/A of Sanford) Mousam River (City Stump Pond Dam City of Sanford N/A of Sanford) Dam Mousam River Estes Lake Dam Dam Town of Alfred N/A (Lower Reach) Mousam River Estes Lake Dam Dam City of Sanford N/A (Lower Reach) Mousam River Dane Perkins (Town of Dam Town of Kennebunk N/A Dam Kennebunk) Mousam River Mousam River (Town of Dam Town of Kennebunk N/A Spillway Kennebunk)

55 Table 8: Non•Levee Flood Protection Measures • continued Type of Description Flooding Source Structure Name Measure Location of Measure Mousam River (Town of N/A Dam Town of Kennebunk N/A Kennebunk) Mulloy Brook N/A Culvert Town of Berwick N/A Towns of Ogunquit Ogunquit River N/A Dam N/A and Wells Central Maine Ossipee River Power Company Dam Town of Parsonsfield N/A Dam Central Maine Ossipee River Power Company Dam Town of Parsonsfield N/A Dam Old Wooden Ossipee River Dam Town of Parsonsfield N/A Dam Saco River Bar Mills Dam Dam Town of Buxton N/A Saco River Bar Mills Dam Dam Town of Hollis N/A Bonny Eagle Saco River Dam Town of Hollis N/A Hydro Station Saco River Cataract Dam Dam City of Biddeford N/A Saco River Cataract Dam Dam City of Saco N/A Cities of Biddeford and Saco River N/A Dam N/A Saco, Town of Hollis Skelton Station Saco River Dam Town of Buxton N/A Dam Skelton Station Saco River Dam Town of Dayton N/A Dam Saco River Springs Dam Dam City of Biddeford N/A Saco River Springs Dam Dam City of Saco N/A Saco River Springs Dam Dam City of Biddeford N/A West Buxton Saco River Dam Town of Buxton N/A Dam West Buxton Saco River Dam Town of Hollis N/A Dam Salmon Falls River Crib Dam Dam Town of Lebanon N/A Milton Leather Salmon Falls River Dam Town of Lebanon N/A Board Dam Milton Three Salmon Falls River Dam Town of Lebanon N/A Ponds Dam

56 Table 8: Non•Levee Flood Protection Measures • continued Type of Description Flooding Source Structure Name Measure Location of Measure Towns of Acton, Salmon Falls River N/A Dam N/A Berwick, Lebanon 1% Annual Chance Flood Sawyer Brook N/A Discharge City of Saco N/A Contained In Structure Sawyer Brook N/A Culvert City of Saco N/A Sawyer Brook N/A Wing Wall City of Saco N/A Town of Smith Brook N/A Culvert N/A Kennebunkport Town of Smith Brook N/A Dam N/A Kennebunkport Tributary 1 to Coffin N/A Culvert Town of Berwick N/A Brook West Brook N/A Culvert Town of Wells N/A Worster Brook N/A Culvert Town of Berwick N/A Worster Brook N/A Culvert Town of Berwick N/A Tributary 3

4.4 Levees This section is not applicable to this Flood Risk Project.

Table 9: Levees [Not Applicable to this Flood Risk Project]

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SECTION 5.0 – ENGINEERING METHODS

For the flooding sources in the community, standard hydrologic and hydraulic study methods were used to determine the flood hazard data required for this study. Flood events of a magnitude that are expected to be equaled or exceeded at least once on the average during any 10-, 25-, 50-, 100-, or 500-year period (recurrence interval) have been selected as having special significance for floodplain management and for flood insurance rates. These events, commonly termed the 10-, 25-, 50-, 100-, and 500-year floods, have a 10-, 4-, 2-, 1-, and 0.2% annual chance, respectively, of being equaled or exceeded during any year.

Although the recurrence interval represents the long-term, average period between floods of a specific magnitude, rare floods could occur at short intervals or even within the same year. The risk of experiencing a rare flood increases when periods greater than 1 year are considered. For example, the risk of having a flood that equals or exceeds the 100-year flood (1-percent chance of annual exceedance) during the term of a 30-year mortgage is approximately 26 percent (about 3 in 10); for any 90-year period, the risk increases to approximately 60 percent (6 in 10). The analyses reported herein reflect flooding potentials based on conditions existing in the community at the time of completion of this study. Maps and flood elevations will be amended periodically to reflect future changes.

The engineering analyses described here incorporate the results of previously issued Letters of Map Change (LOMCs) listed in Table 27, “Incorporated Letters of Map Change”, which include Letters of Map Revision (LOMRs). For more information about LOMRs, refer to Section 6.5, “FIRM Revisions.”

5.1 Hydrologic Analyses Hydrologic analyses were carried out to establish the peak elevation-frequency relationships for floods of the selected recurrence intervals for each flooding source studied. Hydrologic analyses are typically performed at the watershed level. Depending on factors such as watershed size and shape, land use and urbanization, and natural or man-made storage, various models or methodologies may be applied. A summary of the hydrologic methods applied to develop the discharges used in the hydraulic analyses for each stream is provided in Table 13. Greater detail (including assumptions, analysis, and results) is available in the archived project documentation.

Pre-countywide Analyses

During major floods, the entire length of the Little River (Town of Kennebunk) in Kennebunk and Wells acts as an estuary. Water-surface elevations during floods are not a function of discharge alone, but a complex function of discharge, flood volume, tide levels, and wind effects. Rather than attempt to treat these factors separately, the Atlantic Ocean tidal flood elevations were used as the flood elevations for this estuary. Since the peak discharges of the Little River (Town of Kennebunk) would not be used in flooding analysis, no hydrology has been established for the Little River in these towns.

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Flood flows for the various frequencies of the Great Works River and Goodall Brook were computed from an analysis of stream hydraulics, soil cover, land use, and rainfall data using the USDA NRCS TR-20 computer program (USDA NRCS 1965). A 24-hour duration storm and normal antecedent moisture conditions were used. All flood flows were reservoir routed through Bauneg Beg Pond. The discharges obtained from the TR- 20 program are somewhat higher than those estimated from a USGS regression equation; however, they fall within the standard errors of estimate for the equation (USGS 1975).

For the Little Ossipee River, flood flows for the 10-, 2-, 1-, and 0.2-percent annual chance floods were computed using the USDA NRCS TR-20 computer program (USDA NRCS 1965). A 24-hour duration storm and normal antecedent moisture conditions were used. The USGS gage (No. 01066500) located on the Little Ossipee River near South Limington has a period of record of 36 years. The computed discharges correlated favorably with a log-Pearson Type III analysis of the gage data (USGS 1975).

For the Littlefield River in the Town of Alfred and Mousam River (Lower Reach) in the City of Sanford and Town of Alfred, the primary source of peak-flow data used to determine flood discharges for the flooding sources studied by detailed methods was USGS gaging station No. 01069500, on the Mousam River near West Kennebunk. The West Kennebunk gage is located approximately 0.5 mile downstream of Estes Lake Dam and has a drainage area of approximately 99 square miles. Records of flood peaks were available at this gage from 1940 to 1984. The 1-percent-annual-chance discharge at the gage was based on a log-Pearson Type III analysis of annual peak flow data (USGS 1981).

Peak discharges upstream from the USGS gage were established by adjusting the discharge computed at the gage from differences in drainage area between the upstream site and the gage using the following formula:

b Q = Q g(A/A g) where Q is the desired 1-percent-annual-chance flood discharge at the upstream site, Q g is the 1-percent-annual-chance flood discharge at the USGS gage, and A and A g, are drainage areas at the respective sites. The value of the exponent b is 0.8.

Since the gage is located downstream of all regulation affecting Sanford, the peak flow data already takes into account the effects of any regulation by upstream lakes and reservoirs. The flood discharges computed at the gage were modified on the basis of drainage area relationships to compute the adopted discharges in Sanford (USGS 1975). The discharges for the Mousam River (Lower Reach) were derived from discharges calculated for Estes Lake. According to USGS Water-Supply Paper 1580-B, a useable storage capacity of less than 4.5 million cubic feet per square mile, in general, affects peak discharges by less than 10 percent (USGS 1962). The useable storage capacity of Estes Lake is less than this limit; therefore, it was not considered in the computation of upstream flood discharges. The 1-percent-annual-chance flood flow for Tributary to Middle Branch Mousam River was determined using the USGS regional regression equation for the region (USGS 1975).

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Two USGS gages on the Ossipee River were used to establish the peak discharge- frequency relationships. The gage located at Effingham Falls, , has 34 years of record, and the gage located at Cornish, Maine, has 60 years of record (USGS 1960 and USGS 1976c). Values of the 10-, 2-, 1-, 0.2-percent-annual-chance peak discharges were obtained from a log-Pearson Type III distribution of annual peak flow data in accordance with the U.S. Water Resources Council Bulletin 17 (WRC 1976). Peak flows for other locations on the Ossipee River were computed by use of the b drainage area proration method mentioned above, Q = Q g(A/A g) (Chow 1964). The value of b applied to the Ossipee River was 0.8. This value was based on the analysis of peak discharges at the two gages listed above.

In the pre-countywide July 4, 1988, FIS for the Town of Kennebunkport, the 1-percent- annual-chance flood elevation at the Lake of the Woods area was also determined by the proportion method, with a transposition coefficient of 0.75. Reservoir routing was performed to find the water-surface elevation of that flood in this area.

The stage-frequency relationship for the Piscataqua River in the Town of Eliot was established through information obtained in a review of flood history of the area and the pre-countywide FIS’s for the Towns of South Berwick and Kittery, Maine, and the Cities of Portsmouth and Dover, New Hampshire (USGS 1937, USGS 1979, FEMA 1985, FEMA 1984, FEMA 1982a, and FEMA 1980). In the pre-countywide FIS’s for the downstream communities of Kittery and Portsmouth, New Hampshire, the 1-percent- annual-chance flood elevations for the Piscataqua River were determined to be 8.0 and 8.2 respectively (FEMA 1984 and FEMA 1982a). These elevations agree with high-water data obtained by USGS staff during the February 1978 flood, which was considered a 1- percent-annual-chance event. In the FIS for the City of Dover, New Hampshire, a 1- percent-annual-chance elevation of 8.4 feet was determined for the Cocheco River near its confluence of the Piscataqua River (FEMA 1980). Based on these results, a 1- percent-annual-chance flood elevation for the entire length of the Piscataqua River in Eliot was determined to be 8.3 feet.

The computation of flow past the hydro-power plant at West Buxton was the principal source of data for defining discharge frequency relationships for the Saco River. Records of annual, maximum daily discharges were furnished to the USGS by the Central Maine Power Company. Discharges were computed from records of flow over dam, through waste gates, and through wheels of the power plant. The data cover a period of 66 years (1908-1916 and 1920-1977). Discharge figures for this station have not been published by the USGS since 1940; prior to 1940 this data was published as "Station 01067000, Saco River at West Buxton, Maine."

Values for the 10-, 2-, 1-, and 0.2-percent annual chance peak discharges were obtained from a log-Pearson Type III distribution of these annual, maximum daily flow data (WRC 1977). The results from this analysis increased by 1.7 percent to simulate instantaneous discharge because the flow data for West Buxton are values of maximum daily discharge. The 1.7-percent factor was determined to be the average amount by which instantaneous peak flows exceeded concomitant daily flows at West Buxton, and was based on a comparison of 59 events. The instantaneous peak discharges were computed from flow through wheels and gates and flow over spillways. Because of the difference in drainage area from West Buxton (1,571 square miles) to the Hollis-Dayton corporate limits (1,594 square miles), further increases in the peak flow were required to

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estimate flow at the downstream end of the study area. The area at the Hollis-Limington corporate limits is 1,550 square miles, so a slight decrease in flow was made for the upstream end of the reach. Flood discharges for the right and left channel around Bonny Eagle Island were computed using' split flow techniques. The largest part of the flow goes through the left channel, where the spillway section of the dam is located.

The hydrologic analyses for Salmon Falls River were taken from the pre-countywide FIS’s for the Cities of Somersworth and Rochester, New Hampshire (FEMA 1982c and FEMA 1982b). Flood discharge-frequencies for the Salmon Falls River were computed using log-Pearson Type III statistical analyses (WRC 1977) of peak discharges at gage No. 01072500 located on the Salmon Falls River near South Lebanon, Maine. The gage was in operation from 1930 to 1969.

For the March 16, 1998, FIS for the City of Saco, Sawyer Brook discharges were computed using the NRCS TR-20 computer program (USDA NRCS 1983). This program used historical rainfall data for all computed frequencies. Modeled storms had 24-hour duration and a Type III rainfall distribution.

The Batson, Josias, Kennebunk, Ogunquit, Ogunquit Tributary and Little Rivers, the Bog, Goosefare, Great, and Smith Brooks, Spruce and Spinney Creeks, and miscellaneous streams and rivers throughout the County of York are ungaged. The 10-, 2-, 1-, and 0.2-percent annual chance flood peak discharges were computed based on the Maine flood magnitude and frequency formulas developed by the USGS, and were found to be applicable to these flood sources (USGS 1975 and FIA 1978). The USGS formulas predict discharges based on the parameters of watershed drainage area, main channel slope, and percentage of area of lakes and ponds.

The values of the peak flows for Cooks and Day Brooks at 10-, 2-, 1-, and 0.2-percent annual chance intervals were obtained using equations developed by R. A. Morrill and outlined in USGS Open-File Report 75-292 (USGS 1975).

The 1-percent-annual-chance flood discharge at the outlets of Bunganut Pond, Swan Pond, Kennebunk Pond, and Roberts-Wadley Pond were determined by applying a USGS regression equation (USGS 1975).

Countywide Analyses

The 10-, 2-, 1-, and 0.2-percent-annual-chance flood flows for Coffin Brook, Coffin Brook Tributary 1, Driscoll Brook, Ferguson Brook, Keay Brook, Little River (Town of Berwick), Mulloy Brook, Worster Brook, and Worster Brook Tributary 3 were computed with regression equations (USGS 1999). The regression equations use drainage area and percent wetlands as explanatory variables. All drainage areas were determined using a Watershed Information System (WISE) (Watershed Concepts Division 2006) and a Geographic Information System (GIS). Basin wetlands were computed with U.S. Fish and Wildlife Service National Wetland Inventory maps at a scale of 1:24,000 with GIS.

For the Mousam River (Town of Kennebunk), flood frequency curves including the 10-, 2-, 1-, and 0.2-percent-annual-chance flood flows at Whichers Mills Road in Kennebunk were updated after the 2007 flood in southern Maine (USGS 2007). Although continuous data were collected at this historical gage on the Mousam River near Kennebunk (USGS

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Station number 01069500) from 1939 through 1984, a number of historical peak flows occurred at this station outside of the period of record (1996, 2006, and 2007). Peak flows for selected recurrence intervals were estimated by use of the Expected Moments Algorithm (Cohn and Baier 1997) in order to make better use of the historical peak flow data outside of the period of record. Although station number 01069500 is not in the study area of this detailed flood insurance study, drainage area adjustments were made to the published peak discharges at West Kennebunk in order to estimate peak discharges at three locations on the Mousam River: Twine Mill Dam, the confluence with Day Brook, and US Route 1.

Peak discharges for the same three locations were estimated through drainage area adjustments by use of the following equation:

Qungaged = Q gaged (DA ungaged /DA gaged )b; where Q is the flow in cubic feet per second, DA is the drainage area in square miles, and b is a coefficient that depends on the recurrence interval (USGS 1999). Although values of b are published for many recurrence intervals in Hodgkins’ report, b was computed specifically for each location and each recurrence interval along the Mousam River in Kennebunk using the formula listed above, and solving for b. Initial values for gaged and ungaged discharge were determined through regression equations that depend on drainage area and percent wetland in the basin (USGS 1999). Regression equations used without the adjustments listed above are inappropriate along the Mousam River because of the regulation in this watershed.

Drainage areas were calculated using Watershed Information System (WISE) (Watershed Concepts Division 2006). Basin wetlands were computed with U.S. Fish and Wildlife Service National Wetland Inventory maps at a scale of 1:24,000 with GIS.

All other previously detail studied areas were re-delineated in 2013 using LiDAR information except for; Goosefare Brook, Kennebunk River, Littlefield River, Mill Brook, Mousam River, Ossipee River, and the Saco River.

For this countywide study, all existing approximate analysis reaches were restudied by approximate methods by Atkins in 2013 (Atkins 2013) and Ransom Consulting Engineers and Scientists in 2012 (Ransom 2012). For the Atkins study, the discharges were computed using the SCS TR20 method using Runoff Curve numbers. The reaches covered all existing pre-countywide study reaches except for in the Town of Kennebunkport.

In the Town of Kennebunkport, approximate analysis reaches were studied by Ransom Consulting Engineers and Scientists (Ransom 2012). Discharges were calculated using the SCS TR20 method using Runoff Curve numbers and Times of Concentrations for subwatersheds, using 1-percent-annual-chance rainfall distribution for a 24-hour storm. Non-steady flow simulations were used to account for storage and timing differences of peak passage within the watershed. The Cornell University “Extreme Precipitation in New York and New England” website (Cornell 2012) was accessed in 2012 to obtain the 1-percent-annual-chance, 24-hour rainfall.

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A summary of the discharges is provided in Table 10. Frequency Discharge-Drainage Area Curves used to develop the hydrologic models may also be shown in Figure 7 for selected flooding sources. A summary of stillwater elevations developed for non-coastal flooding sources is provided in Table 11. (Coastal stillwater elevations are discussed in Section 5.3 and shown in Table 17.) Stream gage information is provided in Table 12.

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Table 10: Summary of Discharges

Peak Discharge (cfs) Drainage Area (Square 10% Annual 4% Annual 2% Annual 1% Annual 1% Annual 0.2% Annual Flooding Source Location Miles) Chance Chance Chance Chance Chance Future Chance At dam near U.S. Batson River 5.76 408 * 693 849 * 1,310 Route 1 Blacksmith Brook At U.S. Route 1 2.25 179 * 312 385 * 607 Bridges Swamp At mouth 1.09 110 * 198 249 * 403 Bunganut Pond At outlet 2.91 * * * 165 * * At confluence with Cape Neddick River Cape Neddick 9.53 479 * 785 950 * 1,420 Harbor Chickering Creek At Dana Avenue 0.15 73 * 108 123 * 155 Above confluence Cider Hill Creek 4.99 285 * 477 582 * 886 with York River At confluence with Coffin Brook 0.91 173 * 291 350 * 505 Worster Brook About ¾ mile downstream from School Street, upstream from Coffin Brook 0.50 106 * 182 219 * 320 confluence with Unnamed Stream (Coffin Brook Tributary 1) About 2,030 ft Coffin Brook downstream from 0.37 80.4 * 138 168 * 245 School Street

64 Table 10: Summary of Discharges • continued Peak Discharge (cfs) Drainage Area (Square 10% Annual 4% Annual 2% Annual 1% Annual 1% Annual 0.2% Annual Flooding Source Location Miles) Chance Chance Chance Chance Chance Future Chance Coffin Brook At confluence with 0.39 89.3 * 154 186 * 273 Tributary 1 Coffin Brook About 350 ft Coffin Brook upstream from 0.31 73 * 127 154 * 226 Tributary 1 Mayberry Lane Cooks Brook At Dyer Road 10.30 494 * 803 968 * 1,440 At Clarks Mill (State Cooks Brook 9.82 469 * 772 934 * 1,410 Route 35) Cooks Brook At State Route 5 8.76 469 * 772 934 * 1,410 Dayton-Hollis- Cooks Brook Lyman corporate 7.11 382 * 632 766 * 1,160 limits At confluence with Day Brook 2.68 194 * 335 412 * 644 the Mousam River Depot Brook At U.S. Route 1 1.41 124 * 219 273 * 436 Above confluence Dolly Gordon Brook 3.42 196 * 329 400 * 613 with York River Above Maine Dolly Gordon Brook 1.25 88 * 147 179 * 274 Turnpike At downstream Driscoll Brook 1.72 146 * 231 273 * 377 corporate limits At Blackmore Road, about 3,150 ft Driscoll Brook upstream from 1.24 95.9 * 152 179 * 247 downstream corporate limits

65 Table 10: Summary of Discharges • continued Peak Discharge (cfs) Drainage Area (Square 10% Annual 4% Annual 2% Annual 1% Annual 1% Annual 0.2% Annual Flooding Source Location Miles) Chance Chance Chance Chance Chance Future Chance Upstream from confluence with Driscoll Brook - Unnamed Stream, 0.47 40.8 * 65.8 78.2 * 109 continued about 4,100 ft downstream from Blackberry Hill Road At Blackberry Hill Driscoll Brook 0.29 17 * 26.9 31.8 * 43.9 Road At USGS gage No. Estes Lake 99.00 * * * 4,000 * * 01069500 At outlet of Estes Estes Lake 98.00 * * * 4,000 * * Lake Above confluence with Mousam River Estes Lake 50.50 * * * 2300 * * (Littlefield River Branch) At confluence with Ferguson Brook 0.65 91.4 * 152 182 * 259 Worster Brook About 2,260 ft Ferguson Brook downstream from 0.44 60.8 * 101 121 * 174 School Street About 1,420 ft Ferguson Brook upstream from 0.21 38.7 * 66.5 80.5 * 118 School Street Fuller Brook Above Haley Road 0.31 * * * 166 * * Goodall Brook At Berwick Road 0.90 110 * 190 220 * 250

66 Table 10: Summary of Discharges • continued Peak Discharge (cfs) Drainage Area (Square 10% Annual 4% Annual 2% Annual 1% Annual 1% Annual 0.2% Annual Flooding Source Location Miles) Chance Chance Chance Chance Chance Future Chance Goosefare Brook - At confluence of 6.45 410 * 689 840 * 1,284 continued Branch Brook At the Boston and Goosefare Brook Maine Railroad 3.98 279 * 468 571 * 873 bridge Upstream of Ross Goosefare Brook 2.82 211 * 355 433 * 662 Road Great Works River At Vine Road 86.30 4210 * 6,950 8,010 * 11,000 At Emery's Bridge Great Works River 82.10 4000 * 6,620 7,640 * 10,500 Road At Old South Great Works River 46.10 1780 * 3,110 3,640 * 5,180 Berwick Road Great Works River At State Route 9 36.90 1070 * 2,000 2,360 * 3,930 Great Works River At Oak Woods Road 22.10 550 * 1,160 1,370 * 2,160 At the outlet of Great Works River 18.20 540 * 1,060 1,240 * 1,710 Bauneg Beg Pond Great Works River At Sand Pond Road 11.40 930 * 1,660 1,940 * 2,640 Great Works River At Twombley Road 3.50 440 * 740 860 * 970 At confluence with Green Brook 5.02 397 * 660 801 * 1,211 Ogunquit River Hill Creek At Haley Road 0.47 * * * 400 * * At confluence with Josias River 7.31 546 * 930 1,140 * 1,760 The Basin

67 Table 10: Summary of Discharges • continued

Peak Discharge (cfs) Drainage Area (Square 10% Annual 4% Annual 2% Annual 1% Annual 1% Annual 0.2% Annual Flooding Source Location Miles) Chance Chance Chance Chance Chance Future Chance Josias River - Upstream of Shore 6.65 506 * 862 1,057 * 1,632 continued Road At confluence with Keay Brook 11.60 470 * 692 796 * 1,050 Salmon Falls River Upstream from confluence with Murdock Lake Keay Brook 9.20 421 * 626 723 * 960 tributary, about 500 ft downstream from Ridlon Road Upstream from confluence with Unnamed Tributary, Keay Brook 8.40 403 * 601 695 * 925 about 3,100 ft upstream from Ridlon Road Kennebunk Pond At outlet (west) 1.14 * * * 69 * * Kennebunk River At mouth 52.88 2,317 * 3,644 4,335 * 6,262 Little Ossipee River At the mouth 187.00 4,630 * 7,890 9,640 * 14,800 At USGS gage No. Little Ossipee River 168.00 4,250 * 7,240 8,850 * 13,600 01066500 At the Limington- Little Ossipee River Limerick-Waterboro 157.00 4,030 * 6,860 8,380 * 12,900 town boundary At Little Ossipee Little Ossipee River 155.20 2,900 * 6,400 7,800 * 12,000 Flowage Outlet Dam

68 Table 10: Summary of Discharges • continued Peak Discharge (cfs) Drainage Area (Square 10% Annual 4% Annual 2% Annual 1% Annual 1% Annual 0.2% Annual Flooding Source Location Miles) Chance Chance Chance Chance Chance Future Chance Little Ossipee River At State Route 5 112.40 4,000 * 7,400 9,000 * 13,400 - continued At a point approximately 2,500 Little Ossipee River feet below the 66.50 1,700 * 3,300 4,000 * 6,000 upstream corporate limits Little Ossipee River At State Route 11 21.70 370 * 690 830 * 1,250 Little Ossipee River At Balch Pond Road 14.00 250 * 470 550 * 760 Little River (Town At confluence with 54.40 1,771 * 2,517 2,862 * 3,685 Of Berwick) Salmon Falls River About 2,500 ft Little River (Town downstream from 51.70 1,644 * 2,334 2,653 * 3,413 Of Berwick) Long Swamp Road At a point Little River (Town approximately 2.4 6.31 423 * 715 874 * 1,342 Of Berwick) miles upstream of its mouth Little River (Town At mouth 6.31 423 * 715 874 * 1,342 Of Berwick) Upstream from confluence with Little River (Town Unnamed Stream, 49.20 1,545 * 2,193 2,492 * 3,206 Of Cornish) about 1.2 mi downstream from Diamond Hill Road

69 Table 10: Summary of Discharges • continued Peak Discharge (cfs) Drainage Area (Square 10% Annual 4% Annual 2% Annual 1% Annual 1% Annual 0.2% Annual Flooding Source Location Miles) Chance Chance Chance Chance Chance Future Chance Little River (Town Confluence with Of Cornish) - 7.60 620 * 1,060 1,310 * 2,070 Ossipee River continued At USGS gage No. Littlefield River 99.00 * * * 4,000 * * 01069500 At outlet of Estes Littlefield River 98.00 * * * 4,000 * * Lake Above confluence with the Mousam Littlefield River 50.50 * * * 2,330 * * River (Littlefield River Branch Above confluence Littlefield River 43.50 * * * 2,070 * * with Hay Brook Above confluence Littlefield River 22.40 * * * 1,220 * * with Middle Branch At outlet of Shaker Littlefield River 19.40 * * * 1,080 * * Pond Merriland River At Lords Road 16.81 935 * 1,529 1,846 * 2,757 (Lower Reach) Merriland River At Hobbs Road 10.77 602 * 993 1,202 * 1,807 (Upper Reach) Middle Branch At State Route2/US. 16.20 * * * 1,547 * * Mousam River Route 202 Mill Brook At Ross Road 2.68 169 * 288 354 * 547 At Meetinghouse Moors Brook 2.83 264 * 466 579 * 921 Road

70 Table 10: Summary of Discharges • continued

Peak Discharge (cfs) Drainage Area (Square 10% Annual 4% Annual 2% Annual 1% Annual 1% Annual 0.2% Annual Flooding Source Location Miles) Chance Chance Chance Chance Chance Future Chance Mousam River (City At inlet to Estes 47.50 1,380 * 2,020 2,340 * 3,160 of Sanford) Lake At small mill dam Mousam River (City approximately 420 41.50 1,240 * 1,820 2,100 * 2,840 of Sanford) feet downstream of Washington Street Mousam River (City At Mill Pond Dam 37.30 1,140 * 1,670 1,930 * 2,610 of Sanford) Upstream of confluence of Mousam River (City unnamed tributary 32.00 1,000 * 1,470 1,710 * 2,310 of Sanford) approximately 1170 feet downstream of Stanley Road Mousam River At downstream 102.00 * * * 4,000 * * (Lower Reach) corporate limits Mousam River At US Route (Town Of 111.60 3,560 * 6,660 8,560 * 15,040 1/Kesslan Dam Kennebunk) Mousam River At confluence with (Town Of 107.70 3,390 * 6,340 8,160 * 14,320 Day Brook Kennebunk) Mousam River (Town Of Twine Mill Dam 106.70 3,320 * 6,220 7,990 * 14,030 Kennebunk) At confluence with Mulloy Brook 0.47 87 * 148 178 * 258 Worster Brook

71 Table 10: Summary of Discharges • continued

Peak Discharge (cfs) Drainage Area (Square 10% Annual 4% Annual 2% Annual 1% Annual 1% Annual 0.2% Annual Flooding Source Location Miles) Chance Chance Chance Chance Chance Future Chance About 1,900 ft Mulloy Brook - upstream from 0.28 71 * 124 152 * 224 continued School Street Ogunquit River At breached dam 14.60 933 * 1,551 1,882 * 2,845 Downstream of Ogunquit River 13.16 859 * 1,427 1,732 * 2,618 Maine Turnpike Ogunquit River At mouth 13.16 933 * 1,551 1,882 * 2,845 Upstream of Maine Ogunquit River 12.94 847 * 1,408 1,709 * 2,583 Turnpike East of Maine Ogunquit River 12.94 859 * 1,427 1,732 * 2,618 Turnpike Upstream of North Ogunquit River 11.94 794 * 1,321 1,602 * 2,422 Village Road West of Maine Ogunquit River 11.94 847 * 1,408 1,709 * 2,583 Turnpike Ogunquit River At confluence with 1.01 110 * 182 221 * 334 Tributary Ogunquit River Cornish Gage (No. Ossipee River 453.00 7,840 * 11,760 13,690 * 18,890 01065500) Ossipee River At Corporate Limits 450.00 7,715 * 11,575 13,470 * 18,590 Upstream of Mill Ossipee River 388.00 6,920 * 10,380 12,080 * 16,670 Brook Upstream of South Ossipee River 354.00 6,435 * 9,655 11,240 * 15,510 River

72 Table 10: Summary of Discharges • continued

Peak Discharge (cfs) Drainage Area (Square 10% Annual 4% Annual 2% Annual 1% Annual 1% Annual 0.2% Annual Flooding Source Location Miles) Chance Chance Chance Chance Chance Future Chance Roberts-Wadley At outlet 9.00 * * * 233 * * Pond Saco River At Springs Dam 1680.00 25,800 * 38,600 45,000 * 62,600 Saco River Saco boundary 1623.00 25,800 * 38,600 45,000 * 62,600 Skelton hydro-power Saco River 1622.00 25,800 * 38,600 45,000 * 62,600 station Buxton-Dayton- Hollis corporate Saco River 1594.00 25,600 * 38,200 44,200 * 61,500 limits (mouth of Cooks Brook) Saco River At Bar Mills Dam 1594.00 25,600 * 38,200 44,200 * 61,500 Saco River At West Buxton dam 1572.00 25,400 * 37,900 44,000 * 61,000 At Bonny Eagle Saco River 1560.00 25,300 * 37,700 43,800 * 60,600 Dam At the Hollis- Saco River Limington-Standish 1550.00 25,200 * 37,500 43,600 * 60,200 town boundary At the Baldwin- Saco River Standish-Limington 1330.00 23,600 * 34,600 39,800 * 53,800 town boundary Cornish Gage (No. Saco River 1298.00 23,065 * 33,790 38,950 * 52,560 01066000) At the Baldwin- Saco River Cornish-Limington 1296.00 23,100 * 33,800 39,000 * 52,600 town boundary

73 Table 10: Summary of Discharges • continued

Peak Discharge (cfs) Drainage Area (Square 10% Annual 4% Annual 2% Annual 1% Annual 1% Annual 0.2% Annual Flooding Source Location Miles) Chance Chance Chance Chance Chance Future Chance At the Buxton-Town Saco River-Left of Standish 1560.00 25,300 * 37,700 43,800 * 60,600 Channel boundary Salmon Falls River At New Dam Road 235.00 4,600 * 7,460 9,000 * 13,800 At Walnut Grove Salmon Falls River 149.00 3,360 * 5,450 6,570 * 10,080 Road At Spaulding Salmon Falls River 130.00 3,050 * 4,940 5,960 * 9,150 Avenue Sawyer Brook At Sawyer Street 0.17 190 * 305 355 * 460 Sawyer Brook At Therrien Avenue 0.09 65 * 110 125 * 165 Smith Brook At State Route 9 1.54 112 * 195 241 * 381 South Branch Of At confluence with 2.77 207 * 347 422 * 645 West Brook West Brook At confluence with Spinney Creek 1.03 99 * 178 222 * 359 the Piscataqua River At the confluence Spruce Creek with the Piscataqua 2.56 167 * 285 349 * 542 River Stevens Brook At U.S. Route 1 2.01 187 * 336 418 * 668 Swan Pond At outlet 0.97 * * * 99 * * Thatcher Brook At Main Street 6.54 353 * 584 708 * 1,069 Tributary 1 To Cape Above private road 2.01 138 * 226 274 * 409 Neddick River

74 Table 10: Summary of Discharges • continued

Peak Discharge (cfs) Drainage Area (Square 10% Annual 4% Annual 2% Annual 1% Annual 1% Annual 0.2% Annual Flooding Source Location Miles) Chance Chance Chance Chance Chance Future Chance Tributary 1 To At confluence with 1.22 136 * 210 255 * 385 Green Brook Green Brook Tributary To Middle Branch Mousam 0.50 35 * 60 75 * 115 River Unnamed Tributary At Burnham Lane 0.04 * * * 221 * * To Stony Brook Approximately 0.5 Webhannet River mile upstream of 5.25 393 * 673 826 * 1,282 U.S. Route 1 At Bragdon Road West Brook 6.61 415 * 696 847 * 1,294 bridge At Bragdon Road West Brook 3.84 268 * 451 549 * 838 culvert At confluence with Worster Brook 7.59 411 * 669 777 * 1,040 Salmon Falls River Upstream from Worster Brook confluence with 6.12 375 * 572 666 * 899 Ferguson Brook Upstream from Worster Brook confluence with 4.71 246 * 972 432 * 580 Coffin Brook Upstream from Worster Brook confluence with 4.24 206 * 311 362 * 484 Mulloy Brook

75 Table 10: Summary of Discharges • continued

Peak Discharge (cfs) Drainage Area (Square 10% Annual 4% Annual 2% Annual 1% Annual 1% Annual 0.2% Annual Flooding Source Location Miles) Chance Chance Chance Chance Chance Future Chance Upstream from confluence with Worster Brook - Unnamed Stream, 2.49 128 * 196 228 * 308 continued about 1.6 mi downstream from Brown Road Worster Brook At Brown Road 0.60 88.2 * 147 176 * 252 About 2,700 ft Worster Brook upstream from 0.36 56.2 * 94.6 114 * 164 Brown Road About 3,700 ft Worster Brook upstream from 0.23 35.3 * 59.7 71.9 * 104 Brown Road Worster Brook At confluence with 0.86 95 * 155 185 * 261 Tributary 3 Worster Brook About 1,620 ft Worster Brook upstream from 0.46 74 * 124 150 * 216 Tributary 3 confluence with Worster Brook About 2,700 ft Worster Brook upstream from 0.16 30 * 53 65 * 95 Tributary 3 confluence with Worster Brook *Not calculated for this Flood Risk Project

Figure 7: Frequency Discharge-Drainage Area Curves [Not Applicable to this Flood Risk Project]

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Table 11 : Summary of Non-Coastal Stillwater Elevations

Elevations (feet NAVD88)

10% Annual 4% Annual 2% Annual 1% Annual 0.2% Annual Flooding Source Location Chance Chance Chance Chance Chance Balch Pond Newfield and Acton 558.4 * 559 559.2 559.8 Entire shoreline Bauneg Beg Pond 208.8 * 209.2 209.6 209.8 within North Berwick Entire shoreline Bauneg Beg Pond 207.3 * 209.2 209.6 209.8 within Sanford Bonny Eagle Dam Pond Buxton * * * 268.4 * Entire shoreline Bunganut Pond * * * 277.1 * within Lyman Entire shoreline Kennebunk Pond * * * 273.8 * within Lyman Lake of the Woods Entire area 10.7 * 11.1 11.3 11.5 Little Ossipee Lake Waterboro 311.3 * 311.7 312.3 314 Ponding Area 1 Town of Alfred * * * 280.8 * Ponding Area 2 South of Roux Road * * * 289.3 * Ponding Area 2 North of Roux Road * * * 290.3 * Ponding Area 3 Town of Alfred * * * 289.3 * Entire shoreline Roberts-Wadley Pond * * * 275.7 * within Lyman Entire shoreline Swan Pond * * * 281.6 * within Lyman *Not calculated for this Flood Risk Project

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Table 12: Stream Gage Information used to Determine Discharges

Agency Drainage Period of Record that Area Flooding Gage Maintains (Square Source Identifier Gage Site Name Miles) From To Little Ossippee Little Ossipee 01066500 USGS River near South N/A 38 years River Limington Effingham Falls, Ossipee River 01065000 USGS N/A NH Ossipee River 01066000 USGS Cornish, ME N/A Saco River at Saco River 01067000 USGS West Buxton, N/A Maine Saco River 01066000 USGS Cornish, ME N/A 60 years Salmon Falls Salmon Falls 01072500 USGS River near South N/A 1930 1969 River Lebanon, Maine

5.2 Hydraulic Analyses Analyses of the hydraulic characteristics of flooding from the sources studied were carried out to provide estimates of the elevations of floods of the selected recurrence intervals. Base flood elevations on the FIRM represent the elevations shown on the Flood Profiles and in the Floodway Data tables in the FIS Report. Rounded whole-foot elevations may be shown on the FIRM in coastal areas, areas of ponding, and other areas with static base flood elevations. These whole-foot elevations may not exactly reflect the elevations derived from the hydraulic analyses. Flood elevations shown on the FIRM are primarily intended for flood insurance rating purposes. For construction and/or floodplain management purposes, users are cautioned to use the flood elevation data presented in this FIS Report in conjunction with the data shown on the FIRM. The hydraulic analyses for this FIS were based on unobstructed flow. The flood elevations shown on the profiles are thus considered valid only if hydraulic structures remain unobstructed, operate properly, and do not fail.

Pre-countywide Analyses

All cross sections, bridges and culverts were surveyed to obtain elevation data, structural data, and structural geometry. Cross sections were selected immediately below changes in stream configuration. Roughness coefficients (Manning’s “n”) were determined by field inspection at each cross section using a step-by-step procedure. Where feasible, transposed cross sections were used to reduce the number of surveyed cross sections. Transposed cross sections are surveyed sections which can be transferred either upstream or downstream to represent a location which is similar in valley shape.

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For the Little Ossipee River in the Town of Acton, topographic data were obtained from 10 surveyed valley and bridge cross sections and from USGS topographic maps (USGS 1942 and USGS 1958-1983). Water-surface elevations of floods were computed using the USDA NRCS WSP-2 computer program (USDA NRCS 1976). Starting water-surface elevations for the Little Ossipee River were obtained from the FIS for the Town of Newfield (described below).

Cross section data for the Littlefield River in Alfred were obtained from USGS topographic maps (USGS 1958-1983 and USGS 1956-1983). Below-water portions of the cross sections were taken from maps of Maine lakes (State of Maine 1967). Water- surface elevations of floods of the selected recurrence intervals for the Littlefield River were computed using the USGS step-backwater computer program (USGS 1988). The starting water-surface elevation at the Estes Lake outlet was determined by applying flow over broad-crested weir equations (USGS 1968b). For the Littlefield River, which was modeled without a floodway, the results of the water-surface computations are tabulated for the selected cross sections.

In Alfred, cross section data for the Mousam River (Lower Reach) and Tributary to Middle Branch Mousam River were obtained through field surveys. Water-surface elevations of floods of the selected recurrence intervals for the Mousam River (Lower Reach) and Tributary to Middle Branch Mousam River were computed using the United States Army Corps of Engineers (USACE) HEC-2 computer program (USACE 1991). The starting water-surface elevations for the Mousam River were assumed to be at critical depth downstream of Old Falls Dam in Kennebunk. Flood profiles were drawn showing computed water-surface elevations for floods of the selected recurrence intervals.

In Arundel, cross sections for the Kennebeck River were obtained from field surveys and photogrammetric mapping. Water-surface profiles of floods of the selected recurrence intervals on the stream studied by detailed methods were computed using the USACE HEC-2 step-backwater model (USACE 1973). Flood profiles were drawn showing computed water-surface elevations for floods of the selected recurrence intervals. Starting water-surface elevations for the Kennebunk River were taken from mean spring high tide.

Cross sections for the backwater analyses of the Salmon Falls River in Berwick were obtained from aerial photographs flown in May 1980 at a scale of 1:9,600 (Moore Survey and Mapping 1980). The below-water sections were obtained by field measurement. Water-surface elevations of floods of the selected recurrence intervals were computed using the USACE HEC-2 step-backwater computer program (USACE 1984b). Flood profiles were drawn showing computed water-surface elevations for floods of the selected recurrence intervals. Starting water-surface elevations were calculated using the slope/area method.

In Biddeford, cross section data for the Little River, Saco River, Moors Brook, Thatcher Brook were obtained from topographic maps compiled from aerial photographs (J.W. Sewall 1977). Below-water sections were obtained from field surveys. Water-surface elevations of floods of the selected recurrence intervals were determined using the USACE HEC-2 step-backwater computer program (USACE 1976b). Starting water- surface elevations for the Saco River were based on the computed pool elevations

79 behind Springs Dam and Bradbury Dam. Starting water-surf ace elevations for the Little River, Moors Brook, and Thatcher Brook were determined based on the mean spring high tide. Flood profiles were drawn showing computed water-surface elevations to an accuracy of 0.5 foot for floods of the selected recurrence intervals.

For the Saco River and Saco River-Right Channel in Buxton, cross sections for the backwater analyses were obtained from topographic maps developed from aerial photographs taken on November 13, 1978 (Hansa 1978c and Hansa 1978e). The below- water sections were obtained by field measurements. Water-surface elevations of floods of the selected recurrence intervals were computed through the use of the USGS E-341 step-backwater computer program (USGS 1976b). The downstream starting water- surface elevations were taken from the FIS’s for the Town of Dayton and the City of Saco (below). These elevations were verified by computations of discharge at the Bradbury and Springs Dams in the Cities of Biddeford and Saco, respectively. The starting water-surf ace elevations upstream of Skelton Station were determined by a log- Pearson Type III analysis of annual, maximum forebay elevations. The water-surface elevations, for the years 1949 to 1978, were furnished by Central Maine Power Company. The starting elevations upstream of West Buxton and Bar Mills Dams were determined from the spillway discharge curves provided by the Central Maine Power Company. Adjustments were made for maximum flow through the hydro-stations at designated flood times. For the streams studied by approximate methods, the 1-percent- annual-chance flood elevations were estimated using a method which was developed by USGS hydrologists at the Augusta, Maine, office. A regional stage-frequency relationship indicated an estimated 10-foot rise over the mapped stream elevation as the inundation limit of the 1-percent-annual-chance flood (USGS 1972).

Cross section data for the Saco River, Ossipee River, and Little River (Town of Cornish) in Cornish were obtained from photogrammetric maps; the below-water sections were obtained by field survey J.W. Sewall 1978). Several small wooden bridges were not studied and are not shown because they are assumed to be washed out during flooding. Water-surface elevations of floods of the selected recurrence intervals were computed through the use of the USACE HEC-2 step-backwater computer program (USACE 1976b). Starting water-surface elevations for the Saco, Ossipee, and Little Rivers were calculated using the slope/area method.

Cross section data for the backwater analyses of the Saco River and Cooks Brook in Dayton and Hollis were obtained from aerial photographs taken for this study on November 13, 1978 (Hansa 1978a and Hansa 1978b). The below-water data were obtained by field measurement. Water-surface elevations of floods of the selected recurrence intervals were computed through use of the USGS E431 step-backwater computer program (USGS 1976b). The starting water-surface elevations on the Saco River were taken from the FIS’s of the Cities of Biddeford and Saco (both are described within this section). These elevations were verified by computations of discharge at the Bradbury and Springs Dams in Biddeford and Saco, respectively. The starting water- surface elevations upstream of Skelton Station Dam were determined by a log-Pearson Type III analysis of annual maximum forebay elevations. Skelton Station Pond is completely flooded by backwater from the Saco River.

In the Dayton and Hollis area, the starting water-surface elevations on Cooks Brook were determined by computations of discharge over Dennett Dam and Clarks Mill Dam.

80

To determine stage-discharge relations for each of these dams, the study contractor made direct readings of pond elevations, surveyed the dams, and recorded their physical dimensions. Reference points were set in the forebays of the dams so the head on the dams could be computed for observed and measured flows. Current-meter measurements were made at both dams, and a relationship between stages and discharges was determined. These ratings were extended on the basis of the standard flow-over-dam formulas (USGS 1968b):

Q = C L (H)3/2 where Q is the discharge being studied (in cfs), C is the coefficient of discharge, L is the length of the dam perpendicular to the direction of flow (in feet), and H is the head on the dam (in feet).

The measurements of flow to obtain values of "C" did not differentiate the flow for leakage or flow through deep gates. The dams were observed during two seasons of high flow and no gate changes were made. Therefore, the assumption was made that the gates are opened only during times of major repair. This assumption was verified by local residents. The coefficient of discharge was determined using the tables and graphs of the USGS Techniques of Water Resources Investigations, which lists "C” values for various dam types (USGS 1968b). The actual "C" value used in the formula given above to compute the flood elevation was based on both of these "C" determinations. This procedure was used for the abandoned dam near Dennett Road, as well as the Clarks Mill Dam. Flood profiles were drawn showing computed water-surface elevations to an accuracy of 0.5 foot for floods of the selected recurrence intervals. For the streams studied by approximate methods in Dayton and Hollis, the 1-percent-annual-chance flood elevations were estimated using a regional stage-frequency relationship which indicates an estimated 10-foot rise over the mapped stream elevation as the inundation limit of the 1-percent-annual-chance flood (USGS 1972).

Also in Hollis, the Flood Hazard Boundary Map (FHBM) was used to delineate additional small, localized areas of flooding, including swamps and ponds (HUD 1976).

In Eliot, cross sectional data for Spinney Creek were obtained from topographic maps compiled from aerial photographs (J.W. Sewall 1977). Below-water sections were obtained from field surveys. Water-surface elevations of floods of the selected recurrence intervals were computed using the USACE HEC-2 step-backwater computer program (USACE 1984b). Flood profiles were drawn showing computed water-surface elevations for floods of the selected recurrence intervals. The starting water-surface elevations for Spinney Creek were determined using the mean spring high tide. Portions of the profiles for Spinney Creek were not prepared where those portions were affected by backwater from the Piscataqua River.

Water-surface profiles for Brook, Batson River, Day Brook, Kennebunk River, Little River, Little River (Town of Kennebunk), and Smith Brook in Kennebunk and Kennebunkport were developed using the USACE HEC-2 step-backwater model was applied (USACE 1973). Cross sectional data for both computer models were obtained from photogrammetric mapping, while below-water cross sections were obtained by field survey. In areas where the streams meander, the channel distances were determined from the centerline of flow in the floodplain, not the stream centerline.

81

In Kennebunk, starting water-surface elevations for the Kennebunk River were taken from mean spring high tide. The slope/area method was used for Day Brook. It was determined that flooding on Branch Brook would be totally controlled by the Atlantic Ocean for the entire length of the detailed study within Kennebunk. The Little River is an estuary, where water-surface elevations are not a function of discharge alone. For this reason, the HEC-2 step-backwater computer program was not used to analyze the flooding on the Little River.

In Kennebunkport, starting water-surface elevations for the Batson River were taken at critical depth. Starting water-surface elevations for the Kennebunk River, Little River, and Smith Brook were determined from the mean spring high tide. It was determined that flooding on the Kennebunk River would be totally controlled by the Atlantic Ocean for the entire length of the detailed study within Kennebunkport.

Cross sectional data for Spinney and Spruce Creeks in Kittery were obtained from topographic maps compiled from aerial photographs (J.W. Sewall 1977). Below-water sections were obtained from field surveys. Water-surface elevations of floods of the selected recurrence intervals were determined using the USACE HEC-2 step-backwater computer program (USACE 1976b). Starting water-surface elevations for Spruce Creek and Spinney Creek were determined using the mean spring high tide.

In Lebanon, the computer model Quick-2, a simple step-backwater modeling program (FEMA 1995) was used to analyze Bog Brook, Great Brook, and Little River. The model requires cross section data, Manning's "n" value, slope, and flow data as input. The input values were determined from field reconnaissance. All of the structures and representative cross sections were modeled for each flooding source. The flood line was produced using engineering judgment. Cross sections for the backwater analyses of the Salmon Falls River were obtained from aerial photographs flown in May 1980 at a scale of 1.0 inch equals 800 feet. The below-water sections were obtained by field measurement. Water-surface elevations of floods of the selected recurrence intervals were computed using the USACE HEC-2 step- backwater computer program (USACE 1968). Starting water-surface elevations for the Salmon Falls River were taken from known elevations in the FIS for the City of Rochester, New Hampshire (FEMA 1982b).

Cross section data for the Little Ossipee River in Limerick were obtained from 21 surveyed valley and bridge cross sections and from USGS topographic maps (USGS 1942). Water-surface elevations of floods of the selected recurrence intervals were computed using the USDA NRCS WSP-2 computer program (USDA NRCS 1976).

In Limington, cross section data for the backwater analyses of the Saco and Little Ossipee Rivers were obtained from aerial photographs (Hansa 1978d). The below-water sections were obtained by field measurements. For the streams studied by approximate methods, the 1-percent-annual-chance flood elevations were estimated by a method developed by USGS hydrologists at the Augusta, Maine, office (USGS 1972). The regional stage-frequency relationship indicates that the inundation limit of the 1-percent- annual-chance flood is an estimated 10 feet higher than the stream elevation as mapped on USGS topographic maps (USGS 1942 and USGS 1958-1983). The Town of Lebanon used this data for their starting water-surface elevation data for the Little Ossipee River.

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For the Bunganut, Kennebunk, Roberts-Wadley, and Swan Ponds in Lyman, cross sections were extended into overbank areas using topographic maps (USGS 1956- 1983). The 1-percent-annual-chance flood elevation for Bunganut Pond was determined by rating the outlet overflow weir and culvert pipe. The outlet weir was rated by applying the USGS step-backwater computer program (FHWA 1986). Traditional flow-over-weir equations were not applicable in this case. Flow through the culvert was determined by applying appropriate formulas published by the USGS (USGS 1968a). The 1-percent- annual-chance flood elevation for Swan Pond was determined by rating the culvert at the outlet of the pond. Flow through the culvert was calculated by applying standard USGS practices (USGS 1968a). Flow over the roadway at the culvert was computed using the USGS step-backwater computer program (FHWA 1986). The 1-percent-annual-chance flood elevation for Kennebunk Pond was determined by rating both the east and west outlets of the pond. The constricted opening at the west outlet was rated by using the USGS step-backwater computer program (FHWA 1986). The culvert at the east outlet was rated using standard USGS practices (USGS 1968a).

The 1-percent-annual-chance flood elevation for Roberts-Wadley Pond in Lyman was calculated using the USGS step-backwater computer program (FHWA 1986). The dam at the outlet of the pond is irregular and has two small breached sections. Traditional weir equations were not appropriate. The step-backwater program was used to compute critical flow over the dam and then to adjust for the effects of velocity head to compute the pond's 1-percent-annual-chance flood elevation. Starting elevations used in step- backwater applications were based on slope-conveyance computations. Resultant flood elevations for the ponds were confirmed by comparisons with knowledge of historical flood elevations obtained from local residents.

Topographic data for Balch Pond and the Little Ossipee River in Newfield were obtained from 10 surveyed valley and bridge cross sections and from USGS topographic maps (USGS 1942 and USGS 1958-1983). Water-surface elevations of floods of the selected recurrence intervals were computed using the USDA NRCS WSP-2 computer program (USDA NRCS 1976). Starting water-surface elevations for the Little Ossipee River were obtained from the FIS for the Town of Limerick (described above).

Topographic data for Bauneg Pond and the Little Ossipee River in North Berwick were obtained from 47 surveyed valley and bridge cross sections and from USGS topographic maps (USGS 1956-1983 and USGS 1958). Water-surface elevations of floods of the selected recurrence intervals were computed using the USDA NRCS WSP-2 computer program (USDA NRCS 1976). Starting water-surface elevations for the Great Works River were obtained from the FIS for the Town of South Berwick (described below).

Water-surface profiles for the Josias River, Oqunquit River, and Oqunquit River Tributary in Ogunquit were developed using the USACE HEC-2 step-backwater computer model was applied USACE 1973). Cross sectional data for both computer models were obtained from photogrammetric mapping, while below-water cross sections were obtained by field survey. Critical depth was used for starting water-surface elevations on the Josias and Ogunquit Rivers. The slope/area method was used to obtain the starting water-surface elevation for the Ogunquit River Tributary. Hydraulic analyses of the shoreline characteristics of the flooding source studied in detail were carried out to provide estimates of the elevations of floods of the selected recurrence intervals along the shoreline.

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Cross sectional data for the Goosefare and Mill Brooks in Old Orchard Beach was obtained from photogrammetric mapping while the below-water sections were obtained by field survey (J.W. Sewall 1977). Water-surface elevations were developed using two computer models. The riverine portions of the streams studied by detailed methods utilized the USACE HEC-2 step-backwater computer program (USACE 1973). Water- surface elevations for the portion of Mill Brook downstream of Ross Road to the Boston & Maine railroad were determined using rainfall data (Department of Commerce 1963). For the streams studied by detailed riverine methods, the starting water-surface elevations were taken at the mean spring tide level of 5.4 feet.

The above-water cross section data for the Ossipee River in Parsonsfield were obtained from photogrammetric maps (J.W. Sewall 1978); the below-water sections were obtained by field survey. Water-surface profiles were developed for the 10-, 2-, 1-, and 0.2-percent-annual-chance floods using a HEC-2 step-backwater computer program (USACE 1976a). The computer program was started using the slope-area method at the confluence of the Ossipee and Saco Rivers and was continued upstream. A trial-and- error procedure was employed to calibrate the program using the flood of record (1936) on the Ossipee River (USGS 1937). Streams studied by approximate methods were checked by information gathered from the detailed study areas, information from the town, and the Flood Hazard Boundary Map (HUD 1977). No normal depth calculations were made for these areas.

Cross section data for the Goosefare Brook, Saco River, and Sawyer Brook in Saco were obtained from topographic maps compiled from aerial photographs (J.W. Sewall 1977). Below-water sections were obtained from field surveys. For the 1984 Town of Saco FIS, water-surface elevations of floods of the selected recurrence intervals for the Saco River and Goosefare Brook were computed using the USACE HEC-2 step- backwater computer program (USACE 1991). Starting water-surface elevations for the Saco River were based on computed pool elevations behind the Springs Dam and the Bradbury Dam. Starting water-surface elevations for Goosefare Brook were determined based on the mean spring high tide.

For the March 16, 1998, Town of Saco FIS, water-surface elevations for Sawyer Brook were computed using the NRCS WSP2 standard step-backwater computer program (USDA NRCS 1993). Starting water-surface elevations for Sawyer Brook were computed using critical depth. Flood profiles were drawn showing computed water-surface elevations for floods of the selected recurrence intervals.

The hydraulic analysis for Goodall Brook and the Great Works River in the September 4, 1984, Town of Sanford FIS was taken from an USDA NRCS flood hazard analysis for the Great Works River (USDA NRCS 1977a). Topographic data were obtained from 47 surveyed valley and bridge cross sections and from USGS topographic maps (USGS 1956-1983 and USGS 1958). Water-surface elevations of floods of the selected recurrence intervals were computed using the USDA NRCS WSP-2 computer program (USDA NRCS 1976).

For the December 3, 1991, Town of Sanford FIS revision, cross section data for the backwater analyses for Bauneg Beg Pond, Estes Lake and Middle Branch were obtained from field surveys conducted during the 1989 field season by the study

84 contractor, and water-surface elevations were computed using the USGS WSPRO step- backwater computer program (FHWA 1986 and USGS 1989b). Flood profiles were drawn showing computed water-surface elevations for floods of the selected recurrence intervals. The hydraulic analysis for Estes Lake and the starting water-surface elevations for the Mousam River at Estes Lake were taken from the FIS for the Town of Alfred (above). Starting water-surface elevations for the Great Works River and Goodall Brook were taken from the USDA NRCS Flood Hazard Analyses for South Berwick (USDA NRCS 1977b). Starting water-surface elevations upstream of each of the seven dams on the Mousam River were determined from stage-discharge relationships based on the surveyed physical characteristics of the dams and appropriate flow over weir equations documented by the USGS (USGS 1968a).

For the July 20, 1998, Town of Sanford FIS revision, water-surface elevations for the 1- percent-annual-chance floods were computed for the Mousam River (Lower Reach) using the USACE HEC-2 computer program (USACE 1990). The starting water-surface was assumed to be at critical depth downstream of Old Falls Dam at Kennebunk and the computer model includes this dam as it controls the water-surface at the Sanford- Kennebunk corporate limits.

Topographic data for the Little Ossippee River in Shapleigh were obtained from 17 surveyed valley and bridge cross sections and from USGS topographic maps (USGS 1942 and USGS 1958-1983). Field surveys were obtained during the summer of 1975. Only those features in the floodplain at the time the surveys were made were considered in the computations. Water-surface elevations of floods of the selected recurrence intervals were computed using the USDA NRCS WSP-2 computer program (Moore Survey and Mapping 1980). Starting water-surface elevations for the Little Ossipee River were obtained from the FIS for the Town of Newfield (described above).

For the Great Works River in South Berwick, topographic data were obtained from 32 surveyed valley and bridge cross sections and from USGS topographic maps (USGS 1956-1983 and USGS 1958). Field surveys were obtained in 1975. Only those features in the floodplain at the time the surveys were made were considered in the computations. Water-surface elevations of floods of the selected recurrence intervals were computed using the USDA NRCS WSP-2 computer program (USDA NRCS 1976). Starting water-surface elevations for the Great Works River were calculated by the slope/area method.

Valley and bridge cross sections for Little Ossipee Lake and Little Ossipee River in Waterboro were obtained from USGS 15-minute series topographic maps (USGS 1942). Water-surface elevations of floods of the selected recurrence intervals for the Little Ossipee River from the downstream corporate limits to the Waterboro-Limington- Limerick town boundary were computed using the USGS step-backwater computer program (USGS 1976a). Water-surface elevations for the Little Ossipee River from the Waterboro-Limington-Limerick town boundary to the upstream corporate limits were computed using the USDA NRCS WSP-2 computer program (USDA NRCS 1976). Starting water-surface elevations for the Little Ossipee River were obtained from the FIS for Limington (described above).

Water-surface elevations for Blacksmith Brook, Depot Brook, Green Brook, Little River (Town of Kennebunk), Merriland River (Lower and Upper Reach), Oqunquit River, South

85

Branch of West Brook, Stevens Brook, Tributary 1 to Green Brook, Webhannet River, and West Brook in Wells were computed using USACE HEC-2 step-backwater model was applied (USACE 1973). Cross sectional data for both computer models were obtained from photogrammetric mapping, while below-water cross sections were obtained by field survey.

Also in Wells, the Little River (Town of Kennebunk) is an estuary where water-surface elevations are not a function of discharge alone. For this reason, the HEC-2 step- backwater computer program was not used in analyzing the flooding on the Little River (Town of Kennebunk) (USACE 1973). Starting water-surface elevations for the Ogunquit, Webhannet, and Meniland Rivers and Blacksmith Brook were taken at critical depth. Starting water-surface elevations for Depot Brook, Green Brook, Stevens Brook, West Brook, and South Branch of West Brook were obtained using the slope/area method. For Tributary 1 to Green Brook, the starting water-surface elevations were taken from the flood profile of Green Brook at their confluence. It was determined that flooding from Branch Brook and Little River is controlled by the Atlantic Ocean for their detailed study lengths within Wells. Flood profiles were drawn showing computed water- surface elevations for floods of the selected recurrence intervals.

In York, cross sections for the Cape Neddick River, Cider Hill Creek, Dolly Gordon Brook, Tributary 1 to Cape Neddick River and the York River were obtained from photogrammetric mapping while below-water sections were obtained by field survey (J.W. Sewall 1977). Water-surface elevations of floods of the selected recurrence intervals were computed using the USACE HEC-2 step-backwater computer program (USACE 1973). For the streams studied by detailed riverine methods, with the exception of Bridges Swamp, the starting water-surface elevations were taken at the mean spring tide level of 5.4 feet. For Bridges Swamp, the starting water-surface elevations were computed using the slope/area method.

Countywide Analyses

Analyses of the hydraulic characteristics of flooding from Coffin Brook, Coffin Brook Tributary 1, Driscoll Brook, Ferguson Brook, Keay Brook, Little River (Town of Berwick), Mousam River (Town of Kennebunk), Mulloy Brook, Worster Brook, and Worster Brook Tributary 3, were carried out to provide estimates of the elevations of floods of the selected recurrence intervals. Users should be aware that flood elevations shown on the FIRM represent rounded whole-foot elevations and may not exactly reflect the elevations shown on the Flood Profiles or in the Floodway Data tables For construction and/or floodplain management purposes, users are encouraged to use the flood elevation data presented in this FIS in conjunction with the data shown on the FIRM.

Cross sections for the flooding source studied by detailed methods were obtained from field surveys and supplemented by LiDAR (Sanborn Map Company, Inc. 2006). All bridges, dams, and culverts were field surveyed to obtain elevation data and structural geometry. In cases where dams and (or) their gates were inaccessible for the Mousam River (Town of Kennebunk), plans were obtained from Kennebunk Power and Light in order to include these structures in the hydraulic model. Locations of selected cross sections used in the hydraulic analyses are shown on the Flood Profiles.

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Water-surface elevations of floods of the selected recurrence intervals for Coffin Brook, Coffin Brook Tributary 1, Driscoll Brook, Ferguson Brook, Keay Brook, Little River (Town of Berwick), Mulloy Brook, Worster Brook, and Worster Brook Tributary 3 were computed using the USACE HEC-RAS 3.1.3 step-backwater computer program (USACE 2001). The starting water surface elevations for the 10-, 2-, 1- and 0.2-percent- annual-chance flow profiles at the mouth were calculated by the HEC-RAS normal depth computation routine and a downstream water surface slopes estimated from channel survey data.

Water-surface elevations of floods of the selected recurrence intervals for Mousam River (Town of Kennebunk) were computed using the USACE HEC-RAS 4.0 step-backwater computer program (USACE 2008). The starting water surface elevations for the 10-, 2-, 1-, and 0.2-percent-annual-chance flow profiles at the mouth were calculated by the HEC-RAS normal depth computation routine and a downstream water surface slope was estimated from channel survey data. Flood profiles were drawn showing computed water-surface elevations for floods of the selected recurrence intervals. The starting water surface elevations for the 10-, 2-, 1-, and 0.2-percent-annual-chance flow profiles downstream of US Route 1 were estimated from channel survey data.

The 1-, and 0.2-percent-annual-chance flood boundaries were drafted with WISE using existing digital topographical maps with 10-ft contour intervals downloaded from the Maine OGIS website (USGS 1983) and available LiDAR Data (Sanborn Map Company, Inc. 2006). Topographic maps were verified and adjusted based on digital orthophoto quads, also downloaded from this site. The 10-, 2-, 1-, and 0.2-percent-annual-chance flood profiles were drafted with WISE (Watershed Concepts Division 2006).

Based on the results of the new coastal analysis, the backwater elevations are revised where necessary. The flooding sources of Batson River, Blacksmith Brook, Bridges Swamp, Cape Neddick River, Cider Hill Creek, Depot Brook, Dolly Gordon Brook, Goosefare Brook, Josias River, Kennebunk River, Little River, Merriland River (Lower Reach), Mill Brook, Moors Brook, Mousam River (Town of Kennebunk), Ogunquit River, Saco River, Salmon Falls River (FDT only), Smith Brook, Spinney Creek, Spruce Creek, Stevens Brook, Webhannet River, and the York river (FIRM only) were revised for backwater elevations.

All other previously detail studied areas were re-delineated in 2013 using LiDAR elevation data obtained for the coastal analyses (Sanborn Map Company, Inc. 2006) except for; Goosefare Brook, Kennebunk River, Littlefield River, Mill Brook, Mousam River, Ossipee River, and the Saco River.

All existing approximate analysis reaches were restudied by approximate methods by Atkins in 2013 (Atkins 2013) and Ransom Consulting Engineers and Scientists in 2012 (Ransom 2012). In the Town of Kennebunkport, approximate analysis reaches were studied by Ransom Consulting Engineers and Scientists (Ransom 2012). All other reaches were studied by Atkins. For both studies, HEC-RAS (USACE 2012) was used to determine the extent of the 1-percent-annual-chance flood. Major bridges and culverts impacting storage were considered in this approach. The reaches covered all existing pre-countywide study reaches.

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For streams for which hydraulic analyses were based on cross sections, locations of selected cross sections are shown on the Flood Profiles (Exhibit 1). For stream segments for which a floodway was computed (Section 6.3), selected cross sections are also listed in Table 24, “Floodway Data.”

A summary of the methods used in hydraulic analyses performed for this project is provided in Table 13. Roughness coefficients are provided in Table 14. Roughness coefficients are values representing the frictional resistance water experiences when passing overland or through a channel. They are used in the calculations to determine water surface elevations. Greater detail (including assumptions, analysis, and results) is available in the archived project documentation.

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Table 13: Summary of Hydrologic and Hydraulic Analyses

Study Limits Study Limits Hydrologic Model Hydraulic Model Date Analyses Flood Zone Flooding Source Downstream Limit Upstream Limit or Method Used or Method Used Completed on FIRM Special Considerations routing flood SCS WSP-2 1977 Balch Pond Entire shoreline Entire shoreline flows through computer (redelineated AE the pond program 2013) Maine flood Approximately magnitude and From the Dam just 3,200 feet USACE HEC- 1981 frequency AE w/ Batson River downstream of upstream of Stone 2 step- (redelineated formulas Floodway State Route 9 Road in the Town backwater 2013) developed by of Kennebunkport. the USGS SCS WSP-2 USGS 1990 Bauneg Beg Entire shoreline Entire shoreline computer WSPRO step- (redelineated AE Pond program backwater 2013) From Maine flood approximately Approximately magnitude and 5,800 feet USACE HEC- 1978 Blacksmith 1,050 feet frequency AE w/ upstream of the 2 step- (redelineated Brook upstream of U.S. formulas Floodway confluence with backwater 2013) Route 1 developed by the Webhannet the USGS River 1979 Bonny Eagle Entire shoreline Entire shoreline N/A N/A (redelineated AE Pond Dam 2013) Maine flood magnitude and Approximately USACE HEC- 1978 From Long Beach frequency AE w/ Bridges Swamp 1,725 ft upstream 2 step- (redelineated Avenue formulas Floodway of Ridge Road backwater 2013) developed by the USGS

89 Table 13: Summary of Hydrologic and Hydraulic Analyses • continued Study Limits Study Limits Hydrologic Model Hydraulic Model Date Analyses Flood Zone Flooding Source Downstream Limit Upstream Limit or Method Used or Method Used Completed on FIRM Special Considerations USGS step- USGS 1989 backwater rating the outlet overflow weir Bunganut Pond Entire shoreline Entire shoreline regression (redelineated AE computer and culvert pipe equation 2013) program Maine flood Confluence of magnitude and USACE HEC- 1978 Cape Neddick Tributary 1 to frequency AE w/ Shore Road 2 step- (redelineated River Cape Neddick formulas Floodway backwater 2013) River developed by the USGS Approximately From a point 750 2010 Chickering 1,240 feet feet upstream of N/A N/A (redelineated AE Creek upstream of Dana Dana Avenue 2013) Avenue Maine flood magnitude and Approximately USACE HEC- 1978 Confluence with frequency AE w/ Cider Hill Creek 10,000 feet 2 step- (redelineated the York River formulas Floodway upstream backwater 2013) developed by the USGS USACE HEC- Approximately RAS 3.1.3 drainage determined using a From its 2007 1,550 feet regression step- Watershed Information System Coffin Brook confluence with (redelineated AE upstream of Route equations backwater (WISE) (Watershed Concepts Worster Brook 2013) 9 computer Division 2006) program USACE HEC- Approximately RAS 3.1.3 drainage determined using a From its 2007 Coffin Brook 3,250 feet regression step- Watershed Information System confluence with (redelineated AE Tributary 1 upstream of equations backwater (WISE) (Watershed Concepts Coffin Brook 2013) Woods Road computer Division 2006) program

90 Table 13: Summary of Hydrologic and Hydraulic Analyses • continued Study Limits Study Limits Hydrologic Model Hydraulic Model Date Analyses Flood Zone Flooding Source Downstream Limit Upstream Limit or Method Used or Method Used Completed on FIRM Special Considerations Approximately one USGS Open- USGS E-341 1979 From Dennett AE w/ Cooks Brook mile upstream of File Report 75- step- (redelineated Dam Floodway State Route 5 292 backwater 2013) Approximately From its USGS Open- USACE HEC- 1981 4,600 feet AE w/ Day Brook confluence with File Report 75- 2 step- (redelineated upstream of Cat Floodway the Mousam River 292 backwater 2013) Mousam Road Maine flood Approximately 850 Approximately magnitude and AE w/ USACE HEC- 1978 feet downstream 3,900 feet frequency Floodway, Depot Brook 2 step- (redelineated of the concrete upstream of the formulas VE w/ backwater 2013) dam concrete dam developed by Floodway the USGS Maine flood magnitude and From its Approximately 100 USACE HEC- 1978 Dolly Gordon frequency AE w/ confluence with feet upstream of 2 step- (redelineated Brook formulas Floodway York River U.S. Route 1 backwater 2013) developed by the USGS USACE HEC- RAS 3.1.3 drainage determined using a Just upstream of 2007 Just downstream regression step- Watershed Information System Driscoll Brook Blackberry Hill (redelineated AE of railroad equations backwater (WISE) (Watershed Concepts Road 2013) computer Division 2006) program primary source of peak-flow data was USGS gaging station No. applying flow Within the Towns Within the Towns log-Pearson 1989 01069500, on the Mousam River over broad- Estes Lake of Alfred and of Alfred and Type III (redelineated AE near West Kennebunk. crested weir Sanford Sanford analysis 2013) Discharges derived from equations discharges calculated for Estes Lake.

91 Table 13: Summary of Hydrologic and Hydraulic Analyses • continued Study Limits Study Limits Hydrologic Model Hydraulic Model Date Analyses Flood Zone Flooding Source Downstream Limit Upstream Limit or Method Used or Method Used Completed on FIRM Special Considerations USACE HEC- RAS 3.1.3 drainage determined using a From its Approximately 850 2007 Ferguson regression step- Watershed Information System confluence with feet upstream of (redelineated AE Brook equations backwater (WISE) (Watershed Concepts the Worster Brook Bromo Road 2013) computer Division 2006) program

From a point Approximately 2012 2,300 feet 5,250 feet Fuller Brook N/A N/A (redelineated AE upstream of Haley upstream of Haley 2013) Road Road From its USDA NRCS Approximately 100 SCS WSP-2 1977 All flood flows were reservoir confluence with TR-20 AE w/ Goodall Brook feet upstream of computer (redelineated routed through Bauneg Beg the Great Works computer Floodway Berwick Road program 2013) Pond River program From a point Maine flood 10,350 feet Approximately magnitude and USACE HEC- Goosefare upstream of its 2,250 feet frequency AE w/ redelineated in 2006 by 2 step- 1978 Brook confluence with upstream of Ross formulas Floodway Woodward & Curran in Saco backwater the Atlantic Ocean Road developed by upstream the USGS USDA NRCS At North Approximately 100 SCS WSP-2 1977 All flood flows were reservoir Great Works TR-20 AE w/ Berwick/Sanford feet upstream of computer (redelineated routed through Bauneg Beg River computer Floodway border Twombley Road program 2013) Pond program From just At Sanford border USDA NRCS upstream of its SCS WSP-2 1977 All flood flows were reservoir Great Works about 2,400 feet TR-20 AE w/ confluence with computer (redelineated routed through Bauneg Beg River upstream of Sand computer Floodway Salmon Falls program 2013) Pond Pond Rd program River

92 Table 13: Summary of Hydrologic and Hydraulic Analyses • continued Study Limits Study Limits Hydrologic Model Hydraulic Model Date Analyses Flood Zone Flooding Source Downstream Limit Upstream Limit or Method Used or Method Used Completed on FIRM Special Considerations Maine flood Approximately 600 magnitude and From its feet upstream of USACE HEC- 1978 frequency AE w/ Green Brook confluence with its confluence with 2 step- (redelineated formulas Floodway the Ogunquit River Tributary to Green backwater 2013) developed by Brook the USGS From a point Approximately 4,450 feet 7,950 feet 2007 Hill Creek upstream of its upstream of its N/A N/A (redelineated AE confluence with confluence with 2013) Spruce Creek Spruce Creek Maine flood Approximately magnitude and From its 1979 1,250 feet frequency HEC-2 step- AE w/ Josias River confluence with (redelineated upstream of U.S. formulas backwater Floodway the Basin 2013) Route 1 developed by the USGS Upstream USACE HEC- From its corporate limit RAS 3.1.3 2007 drainage determined using a confluence with (approximately regression step- Watershed Information System Keay Brook (redelineated AE the Salmon Falls 8,300 feet equations backwater (WISE) (Watershed Concepts 2013) River upstream of computer Division 2006) Ridlon Road) program USGS step- USGS 1989 Kennebunk backwater rating the outlet overflow weir Entire shoreline Entire shoreline regression (redelineated AE Pond computer and culvert pipe equation 2013) program

93 Table 13: Summary of Hydrologic and Hydraulic Analyses • continued Study Limits Study Limits Hydrologic Model Hydraulic Model Date Analyses Flood Zone Flooding Source Downstream Limit Upstream Limit or Method Used or Method Used Completed on FIRM Special Considerations Along border of Kennebunk and Maine flood Kennebunkport. Approximately magnitude and AE w/ USACE HEC- Kennebunk From 2,750 feet frequency Floodway, 2 step- 1981 River approximately 500 upstream of U.S. formulas VE w/ backwater feet upstream of Route 1 in Arundel developed by Floodway its confluence with the USGS the Atlantic Ocean USACE HEC- 2 step- 1978 Lake of the proportion Transposition coefficient of 0.75. Entire shoreline Entire shoreline backwater (redelineated N/A Woods method Reservoir routing computer 2013) program Entire shoreline Entire shoreline within the Town of within the Town of Waterboro Waterboro 1977 Flood Hazard Analyses for the Little Ossipee including the outlet including the outlet N/A N/A (redelineated AE Little Ossipee River in the Towns Lake stream to its stream to its 2013) of Waterboro and Limerick confluence with confluence with the Little Ossipee the Little Ossipee River River To the Limington/Limerick /Waterboro Border log-Pearson USGS E431 1979 USGS gage 01066500 Little Little Ossipee Confluence with (approximately AE w/ Type III step- (redelineated Ossippee River near South River Saco River 600 feet Floodway analysis backwater 2013) Limington 38 years record downstream of New Dam Road in Limerick)

94 Table 13: Summary of Hydrologic and Hydraulic Analyses • continued

Study Limits Study Limits Hydrologic Model Hydraulic Model Date Analyses Flood Zone Flooding Source Downstream Limit Upstream Limit or Method Used or Method Used Completed on FIRM Special Considerations From the Limington/Limerick USDA NRCS /Waterboro Border USDA NRCS WSP-2 1977 USGS gage 01066500 Little Little Ossipee (approximately Confluence with TR-20 computer AE w/ (redelineated Ossippee River near South River 600 feet Balch Pond Dam computer program - in Floodway 2013) Limington 36 years record downstream of program town of acton, New Dam Road in limerick Limerick) Maine flood From Approximately magnitude and approximately 650 2,380 feet USACE HEC- 1978 frequency AE w/ Little River feet upstream of upstream of Oak 2 step- (redelineated formulas Floodway its confluence with Ridge Road in the backwater 2013) developed by the Atlantic Ocean City of Biddeford the USGS Upstream USACE HEC- corporate limit RAS 3.1.3 Drainage determined using a Little River Confluence with (approximately 2007 regression step- Watershed Information System (Town of Salmon Falls 18,300 feet (redelineated AE equations backwater (WISE) (Watershed Concepts Berwick) River upstream of 2013) computer Division 2006) Diamond Hill program Road) Little River 1978 Confluence with State Routes 5 regression HEC-2 step- AE w/ (Town of (redelineated the Ossipee River and 117 equations backwater Floodway Cornish) 2013) Along border of During major floods, the Little Kennebunk and River (Town of Kennebunk) in no hydrology Wells. Along border of Kennebunk and Wells acts as an Little River established, 1978 Approximately Kennebunk and no hydraulics AE, VE w/ estuary, therefore, no hydrology (Town of ocean tidal (redelineated 1,000 feet Wells. Confluence established Floodway has been established for the Kennebunk) flood elevations 2013) upstream of its with Branch Brook Little River. Water-surface used confluence with elevations are not a function of the Atlantic Ocean discharge alone

95 Table 13: Summary of Hydrologic and Hydraulic Analyses • continued

Study Limits Study Limits Hydrologic Model Hydraulic Model Date Analyses Flood Zone Flooding Source Downstream Limit Upstream Limit or Method Used or Method Used Completed on FIRM Special Considerations Approximately 1.8 From Estes Lake miles upstream of Primary source of peak-flow data log-Pearson Dam along border U.S. Route 202 USGS step- was USGS gaging station No. Littlefield River Type III 1989 AE of Alfred and and State Route 4 backwater 01069500, on the Mousam River analysis Sanford in the Town of near West Kennebunk Alfred Maine flood Approximately magnitude and AE w/ From its USACE HEC- 1978 Merriland River 2,900 feet frequency Floodway, confluence with 2 step- (redelineated (Lower Reach) upstream of U.S. formulas VE w/ the Little River backwater 2013) Route 1 developed by Floodway the USGS Maine flood magnitude and The dam just USACE HEC- 1978 Merriland River Approximately 2.1 frequency AE w/ downstream of 2 step- (redelineated (Upper Reach) miles upstream formulas Floodway Hobbs Farm Road backwater 2013) developed by the USGS From approximately 2001 Middle Branch 3,000 feet State Route N/A HEC-RAS (redelineated AE Mousam River upstream of 4/State Route 202 2013) confluence with Estes Lake Maine flood For the entire Water-surface elevations for the magnitude and length within the portion of Mill Brook downstream Approximately 1.2 frequency HEC-2 step- AE w/ Mill Brook community of Old 1978 of Ross Road to the Boston & miles upstream formulas backwater Floodway Orchard Beach, Maine railroad were determined developed by from Ross Road using rainfall data the USGS

96 Table 13: Summary of Hydrologic and Hydraulic Analyses • continued

Study Limits Study Limits Hydrologic Model Hydraulic Model Date Analyses Flood Zone Flooding Source Downstream Limit Upstream Limit or Method Used or Method Used Completed on FIRM Special Considerations Maine flood magnitude and From Approximately 1978 frequency HEC-2 step- AE w/ Moors Brook Meetinghouse 1.55 miles (redelineated formulas backwater Floodway Road in Biddeford upstream 2013) developed by the USGS To the upstream corporate limits Annual peak flow data from Mousam River From its approximately log-Pearson USGS 1990 AE w/ USGS gaging station No. (City of confluence with 1,000 feet Type III WSPRO step- (redelineated Floodway 01069500, on the Mousam River Sanford) Estes Lake upstream of State analysis backwater 2013) (1940-1984) Route 109 in the City of Sanford Primary source of peak-flow data was USGS gaging station No. From the log-Pearson 01069500, on the Mousam River Mousam River Kennebunk- USACE HEC- AE w/ Estes Lake Dam Type III 1995 near West Kennebunk. (Lower Reach) Sanford corporate 2 Floodway analysis Discharges derived from limits discharges calculated for Estes Lake. Flood frequency curves for the From a point Mousam River at Whichers Mills approximately USACE HEC- Road in Kennebunk were Mousam River 2,000 ft Approximately Expected RAS 4.0 step- AE w/ updated after the 2007 flood in (Town of downstream from 500 feet upstream Moments backwater 2008 Floodway, southern Maine. Drainage Kennebunk) the bridge/dam of Mill Street Algorithm computer VE determined using a Watershed combination at US program Information System (WISE) Route 1 (Watershed Concepts Division 2006)

97 Table 13: Summary of Hydrologic and Hydraulic Analyses • continued

Study Limits Study Limits Hydrologic Model Hydraulic Model Date Analyses Flood Zone Flooding Source Downstream Limit Upstream Limit or Method Used or Method Used Completed on FIRM Special Considerations USACE HEC- RAS 3.1.3 Drainage determined using a From its 2007 Approximately 1.3 regression step- Watershed Information System Mulloy Brook confluence with (redelineated AE miles upstream equations backwater (WISE) (Watershed Concepts Worster Brook 2013) computer Division 2006) program Maine flood magnitude and From Beach Confluence with frequency HEC-2 step- AE w/ Ogunquit River 1979 Street Green Brook formulas backwater Floodway developed by the USGS Maine flood magnitude and From its Approximately 1979 Ogunquit River frequency HEC-2 step- AE w/ confluence with 2,950 feet (redelineated Tributary formulas backwater Floodway the Ogunquit River upstream 2013) developed by the USGS Approximately 2.06 miles log-Pearson Primary source of peak-flow data HEC-2 step- AE w/ Ossipee River Border of Cornish upstream of the Type III 1978 from gage at Effingham Falls, backwater Floodway confluence of analysis NH and Cornish, ME South River USACE HEC- Entire length Entire length 2 step- 1987 Piscataqua review of flood within Eliot, Town within Eliot, Town backwater (redelineated AE River history of of computer 2013) program 2006 Ponding Area 1 Entire shoreline Entire shoreline N/A N/A (redelineated AH 2013)

98 Table 13: Summary of Hydrologic and Hydraulic Analyses • continued Study Limits Study Limits Hydrologic Model Hydraulic Model Date Analyses Flood Zone Flooding Source Downstream Limit Upstream Limit or Method Used or Method Used Completed on FIRM Special Considerations 2006 Ponding Area 2 Entire shoreline Entire shoreline N/A N/A (redelineated AH 2013) 2006 Ponding Area 3 Entire shoreline Entire shoreline N/A N/A (redelineated AH 2013) USGS step- USGS 1989 Roberts- backwater Rating the outlet overflow weir Entire shoreline Entire shoreline regression (redelineated AE Wadley Pond computer and culvert pipe equation 2013) program Starting water-surface elevations based on computed pool log-Pearson From West Branch Saco-Buxton- HEC-2 step- AE w/ elevations behind the Springs Saco River Type III 1982 Dam Dayton border backwater Floodway Dam and the Bradbury Dam; analysis redelineated in 2006 by Woodward & Curran log-Pearson USGS E-341 Computation of flow past the Biddeford/Dayton/ Limington and AE w/ Saco River Type III step- 1979 hydro-power plant at West Saco Border Cornish border Floodway analysis backwater Buxton Starting water-surface elevations log-Pearson From West Branch Biddeford-Dayton- HEC-2 step- AE w/ based on computed pool Saco River Type III 1978 Dam Saco border backwater Floodway elevations behind the Springs analysis Dam and the Bradbury Dam Limington and Approximately 2.6 log-Pearson HEC-2 step- AE w/ Gage (01066000) at Cornish, Saco River Cumberland Miles from Hussey Type III 1978 backwater Floodway ME 60 years of record County border Hill Road analysis From its Town of Buxton USGS E-341 1979 Saco River - split flow confluence with upstream step- (redelineated AE Left Channel techniques the Saco River corporate limits backwater 2013)

99 Table 13: Summary of Hydrologic and Hydraulic Analyses • continued

Study Limits Study Limits Hydrologic Model Hydraulic Model Date Analyses Flood Zone Flooding Source Downstream Limit Upstream Limit or Method Used or Method Used Completed on FIRM Special Considerations From a point Peak discharge at gage approximately log-Pearson USACE HEC- 1991 01072500 on Salmon Falls River Salmon Falls AE w/ 3,050 feet Border of Lebanon Type III 2 step- (redelineated near South Lebanon, Maine. River Floodway downstream of analysis backwater 2013) Gage from 1930-1969 New Dam Road Redelineated in 2007 by USGS Transferred from FIRMs for the log-Pearson USACE HEC- 1985 Town of Milton, NH (1988) and Salmon Falls AE w/ Berwick border Acton Border Type III 2 step- (redelineated City of Rochester, NH (1982). River Floodway analysis backwater 2013) Salmon Falls River gage near South Lebanon, Maine. USDA NRCS USDA NRCS Approximately 50 1982 From Sawyer TR-20 WSP-2 Redelineated in 2006 by Sawyer Brook feet upstream of (redelineated AE Street computer computer Woodward & Curran Therrien Avenue 2013) program program Primary source of peak-flow data was USGS gaging station No. log-Pearson 1989 01069500, on the Mousam River Shaker Pond Entire shoreline Entire shoreline Type III N/A (redelineated AE near West Kennebunk. analysis 2013) Discharges derived from discharges calculated for Estes Lake. Maine flood magnitude and Approximately USACE HEC- 1981 From State frequency AE w/ Smith Brook 1,225 feet 2 step- (redelineated formulas Floodway Route 9 upstream backwater 2013) developed by the USGS Maine flood magnitude and From its Approximately USACE HEC- 1978 South Branch frequency AE w/ confluence with 2,225 feet 2 step- (redelineated of West Brook formulas Floodway West Brook upstream backwater 2013) developed by the USGS

100 Table 13: Summary of Hydrologic and Hydraulic Analyses • continued

Study Limits Study Limits Hydrologic Model Hydraulic Model Date Analyses Flood Zone Flooding Source Downstream Limit Upstream Limit or Method Used or Method Used Completed on FIRM Special Considerations On Elliot and Kittery border. On Elliot and Maine flood From USACE HEC- Kittery border. magnitude and approximately 2 step- 1987 Approximately 350 frequency AE w/ Spinney Creek 5,300 feet backwater (redelineated feet upstream of formulas Floodway upstream of its computer 2013) Dennett Road in developed by confluence with program the Town of Eliot. the USGS the Piscataqua River On Elliot and Kittery border. On Elliot and Maine flood From Kittery border. magnitude and approximately USACE HEC- 1982 Approximately 350 frequency AE w/ Spinney Creek 5,300 feet 2 step- (redelineated feet upstream of formulas Floodway upstream of its backwater 2013) Dennett Road in developed by confluence with the Town of Eliot. the USGS the Piscataqua River Maine flood From just magnitude and Approximately USACE HEC- 1982 downstream of frequency AE w/ Spruce Creek 2,100 feet 2 step- (redelineated Wilson Road formulas Floodway upstream backwater 2013) (State Route 101) developed by the USGS Maine flood From Approximately magnitude and approximately 2 2,000 feet USACE HEC- 1978 frequency AE w/ Stevens Brook miles upstream of upstream of U.S. 2 step- (redelineated formulas Floodway its confluence with Route 1 in the backwater 2013) developed by Ogunquit River Town of Wells. the USGS USGS 1989 USGS Rating the outlet overflow weir Swan Pond Entire shoreline Entire shoreline regression (redelineated AE formulas and culvert pipe equation 2013)

101 Table 13: Summary of Hydrologic and Hydraulic Analyses • continued

Study Limits Study Limits Hydrologic Model Hydraulic Model Date Analyses Flood Zone Flooding Source Downstream Limit Upstream Limit or Method Used or Method Used Completed on FIRM Special Considerations Maine flood Approximately magnitude and From its 1978 2,350 feet frequency HEC-2 step- AE w/ Thatcher Brook confluence with (redelineated upstream of South formulas backwater Floodway the Saco River 2013) Street developed by the USGS Maine flood From its Approximately magnitude and Tributary 1 to USACE HEC- 1978 confluence with 1,450 feet frequency AE w/ Cape Neddick 2 step- (redelineated Cape Neddick upstream of formulas Floodway River backwater 2013) River Mountain Road developed by the USGS Maine flood Approximately magnitude and From its USACE HEC- 1978 Tributary 1 to 1,400 feet frequency AE w/ confluence with 2 step- (redelineated Green Brook upstream of formulas Floodway Green Brook backwater 2013) Hiltons Lane developed by the USGS From Approximately Tributary to approximately 200 2,800 feet USGS regional 1995 Middle Branch feet downstream upstream of regression HEC-2 (redelineated AE Mousam River of Middle Branch Middle Branch equations 2013) Drive Drive From a point Approximately Unnamed 2010 approximately 850 3,650 feet Tributary to N/A N/A (redelineated AE feet upstream of upstream of Stony Brook 2013) Burnham Lane Burnham Lane

102 Table 13: Summary of Hydrologic and Hydraulic Analyses • continued

Study Limits Study Limits Hydrologic Model Hydraulic Model Date Analyses Flood Zone Flooding Source Downstream Limit Upstream Limit or Method Used or Method Used Completed on FIRM Special Considerations From Approximately Maine flood approximately 2,950 feet magnitude and AE w/ 3,800 feet USACE HEC- 1978 Webhannet upstream of U.S. frequency Floodway, downstream of 2 step- (redelineated River Route 4 (Blue Star formulas VE w/ U.S. Route 4 (Blue backwater 2013) Memorial developed by Floodway Star Memorial Highway) the USGS Highway) From Approximately Maine flood approximately 3,200 feet magnitude and USACE HEC- 1978 11,000 feet upstream of frequency AE w/ West Brook 2 step- (redelineated upstream of its confluence with formulas Floodway backwater 2013) confluence with the South Branch developed by Great Works River of West Brook the USGS USACE HEC- From its Approximately RAS 3.1.3 2007 Drainage determined using a confluence with 5,900 feet regression step- Watershed Information System Worster Brook (redelineated AE the Salmon Falls upstream of equations backwater (WISE) (Watershed Concepts 2013) River Brown Road computer Division 2006) program USACE HEC- Approximately 150 RAS 3.1.3 Drainage determined using a From its 2007 Worster Brook feet upstream of regression step- Watershed Information System confluence with (redelineated AE Tributary 3 Thompson Hill equations backwater (WISE) (Watershed Concepts Worster Brook 2013) Road computer Division 2006) program Numerous Unnamed Kennebunkport, Kennebunkport, regression Tributaries or HEC-RAS 2012 A Town of Town of equations Local Ponding Areas

103 Table 13: Summary of Hydrologic and Hydraulic Analyses • continued Study Limits Study Limits Hydrologic Model Hydraulic Model Date Analyses Flood Zone Flooding Source Downstream Limit Upstream Limit or Method Used or Method Used Completed on FIRM Special Considerations Numerous Unnamed regression Tributaries or Refer to FIRM Refer to FIRM HEC-RAS 2013 A equations Local Ponding Areas

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Table 14: Roughness Coefficients

Flooding Source Channel “n” Overbank “n” Batson River 0.020-0.050 0.050-0.090 Blacksmith Brook 0.050 0.090 Bridges Swamp 0.050 0.090 Bunganut Pond (at outlet) 0.030-0.045 0.055-0.110 Cape Neddick River 0.013-0.050 0.090 Cider Hill Creek 0.020-0.050 0.050-0.020 Coffin Brook 0.045-0.050 0.090-0.110 Coffin Brook Tributary 1 0.050-0.060 0.100-0.110 Cooks Brook 0.030-0.055 0.040-0.110 Day Brook 0.013-0.050 0.050-0.090 Depot Brook 0.013-0.050 0.050-0.090 Dolly Gordon Brook 0.013-0.050 0.050-0.090 Driscoll Brook 0.040-0.050 0.045-0.100 Ferguson Brook 0.045-0.060 0.050-0.120 Goosefare Brook 0.013-0.050 0.050-0.090 Great Works River 0.030-0.060 0.035-0.110 Green Brook 0.030-0.050 0.030-0.090 Kennebunk Pond (at west outlet) 0.030-0.045 0.055-0.110 Kennebunk River 0.020-0.050 0.090 Keay Brook 0.045-0.060 0.085-0.110 Little Ossipee River 0.015-0.057 0.060-0.100 Little Ossipee River (Limington) 0.020-0.060 0.045-0.125 Little River 0.020-0.050 0.050-0.090 Little River (Cornish) 0.035-0.050 0.080-0.100 Little River(Berwick) 0.045-0.075 0.050-0.150 Littlefield River 0.030-0.045 0.055-0.110 Merriland River 0.013-0.050 0.050-0.090 Mill Brook 0.013-0.050 0.050-0.090 Moors Brook 0.020-0.050 0.050-0.090 Mousam River (Alfred) 0.030-0.070 0.070-0.080 Mousam River (Kennebunk) 0.038-0.045 0.090-0.110 Mousam River (Lower Reach) 0.030-0.070 0.070-0.080

105 Table 14: Roughness Coefficients • continued Flooding Source Channel “n” Overbank “n” Mulloy Brook 0.045-0.060 0.090 Ogunquit River 0.030-0.050 0.090 Ossipee River 0.03-0.0450 0.070-0.090 Roberts-Wadley Pond (at outlet) 0.030-0.045 0.055-0.110 Saco River 0.030-0.055 0.040-0.110 Saco River (Cornish) 0.035-0.045 0.080-0.090 Saco River (Limington) 0.035-0.055 0.045-0.110 Saco River (Saco and Biddeford) 0.050 0.090 Saco River-Right Channel 0.030-0.055 0.040-0.110 Salmon Falls River (Berwick) 0.030-0.045 0.050-0.150 Salmon Falls River (Rochester, 0.030-0.040 0.060-0.150 NH) Salmon Falls River (Milton, NH) 0.030-0.070 0.040-0.120 Sawyer Brook 0.055-0.065 0.080-0.095 Smith Brook 0.013-0.050 0.050-0.090 South Branch of West Brook 0.050 0.090 Spinney Creek 0.013-0.050 0.050-0.090 Spruce Creek 0.013-0.050 0.050-0.090 Stevens Brook 0.013-0.050 0.050-0.090 Swan Pond (at outlet) 0.030-0.045 0.055-0.110 Thatcher Brook 0.013-0.050 0.050-0.090 Tributary 1 to Cape Neddick 0.013-0.050 0.090 River Tributary 1 to Green Brook 0.013-0.050 0.050-0.090 Tributary to Middle Branch 0.045 0.100 Mousam River Webhannet River 0.050 0.090 West Brook 0.013-0.050 0.050-0.090 Worster Brook 0.030-0.470 0.075-0.120 Worster Brook Tributary 3 0.045-0.055 0.050-0.110

5.3 Coastal Analyses For the areas of York County that are impacted by coastal flooding processes, coastal flood hazard analyses were performed to provide estimates of coastal BFEs. Coastal

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BFEs reflect the increase in water levels during a flood event due to extreme tides and storm surge as well as overland wave effects.

The following subsections provide summaries of how each coastal process was considered for this FIS Report. Greater detail (including assumptions, analysis, and results) is available in the archived project documentation. Table 15 summarizes the methods and/or models used for the coastal analyses. Refer to Section 2.5.1 for descriptions of the terms used in this section.

Table 15: Summary of Coastal Analyses

Date Analysis Flooding Study Limits Study Limits Hazard Model or was Source From To Evaluated Method Used Completed Coastline in Coastline in York County York County Overland Atlantic Ocean affected by affected by Wave WHAFIS 10/1/2016 transects 086, transects 086, Propagation 105, 111, 127 105, 111, 127 Coastline in Coastline in York County York County affected by affected by transects 006, transects 006, Overland 017, 025, 026, 017, 025, 026, Atlantic Ocean Wave WHAFIS 10/1/2013 029, 032, 034, 029, 032, 034, Propagation 035, 042, 048, 035, 042, 048, 061, 064, 065, 061, 064, 065, 066, 072, 073, 066, 072, 073, 075, 077, 131 075, 077, 131 Coastline in Coastline in York County York County Atlantic Ocean affected by affected by PFD PFD 10/1/2016 transects 078, transects 078, 082, 093, 120 082, 093, 120 Coastline in Coastline in York County York County affected by affected by Atlantic Ocean transects 062, transects 062, PFD PFD 10/1/2013 063, 074, 133, 063, 074, 133, 134, 135, 139, 134, 135, 139, 144 144

107 Table 15: Summary of Coastal Analyses • continued Date Analysis Flooding Study Limits Study Limits Hazard Model or was Source From To Evaluated Method Used Completed Coastline in Coastline in York County York County affected by affected by transects 080, transects 080, 081, 083, 084, 081, 083, 084, 088, 089, 091, 088, 089, 091, Atlantic Ocean Wave Runup ACES 10/1/2016 092, 098, 103, 092, 098, 103, 106, 107, 108, 106, 107, 108, 109, 110, 112, 109, 110, 112, 114, 115, 116, 114, 115, 116, 117, 118, 121, 117, 118, 121, 122, 125 122, 125 Coastline in Coastline in York County York County affected by affected by Atlantic Ocean Wave Runup ACES 10/1/2013 transects 010, transects 010, 056, 057, 140, 056, 057, 140, 141, 142, 143 141, 142, 143 Coastline in Coastline in York County York County Plateau Atlantic Ocean Wave Runup 10/1/2016 affected by affected by Method transect 124 transect 124 Coastline in Coastline in York County York County Atlantic Ocean Wave Runup ACES Beach 10/1/2013 affected by affected by transect 138 transect 138 Coastline in Coastline in York County York County Atlantic Ocean affected by affected by Wave Runup Runup 2.0 10/1/2016 transects 079, transects 079, 087, 123 087, 123 Coastline in Coastline in York County York County affected by affected by transects 004, transects 004, Atlantic Ocean Wave Runup Runup 2.0 10/1/2013 013, 018, 019, 013, 018, 019, 024, 031, 041, 024, 031, 041, 045, 055, 058, 045, 055, 058, 129, 136 129, 136 Coastline in Coastline in York County York County Atlantic Ocean Wave Runup SPM 10/1/2016 affected by affected by transect 119 transect 119

108 Table 15: Summary of Coastal Analyses • continued Date Analysis Flooding Study Limits Study Limits Hazard Model or was Source From To Evaluated Method Used Completed Coastline in Coastline in York County York County Atlantic Ocean affected by affected by Wave Runup SPM 10/1/2013 transects 060, transects 060, 070, 071, 076 070, 071, 076 Coastline in Coastline in York County York County affected by affected by transects 85, transects 85, Atlantic Ocean Wave Runup TAW 10/1/2016 90, 94, 95, 96, 90, 94, 95, 96, 97, 99, 100, 97, 99, 100, 101, 102, 104, 101, 102, 104, 113, 126, 128 113, 126, 128 Coastline in Coastline in York County York County affected by affected by transects 001, transects 001, 002, 003, 005, 002, 003, 005, 007, 008, 009, 007, 008, 009, 011, 012, 014, 011, 012, 014, 015, 016, 020, 015, 016, 020, 021, 022, 023, 021, 022, 023, Atlantic Ocean Wave Runup TAW 10/1/2013 027, 028, 030, 027, 028, 030, 033, 036, 037, 033, 036, 037, 038, 039, 040, 038, 039, 040, 043, 044, 046, 043, 044, 046, 047, 049, 050, 047, 049, 050, 051, 052, 053, 051, 052, 053, 054, 059, 067, 054, 059, 067, 068, 069, 130, 068, 069, 130, 132, 137 132, 137

The coastal analysis in York County is divided into three groups according to the type of study performed by the STARR team. The three groups are referred to in this report as “New Transects,” “Updated Map Mod Transects,” and “Re-Evaluated Transects.” Below is a description of each group.

New Transects

Contains the 60 transects in the City of Saco and the towns of Wells and York in addition to one transect in the Town of Kennebunk. A completely new RiskMap engineering analysis was performed for these transects. This analysis includes transect numbers 18-54, 64-78, and 129-136.

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Updated Map Mod Transects

Contains 34 transects in the towns of Kittery, Ogunquit, and Old Orchard Beach. This study updated the former analysis (performed as part of FEMA’s previous Map Modernization Program) by updating input wave conditions from a newer wave model (Map Mod 2008). This analysis includes transect numbers 1-17, 55-63, and 137-144.

Re-Evaluated Transects

Contains the 50 transects in the City of Biddeford and the towns of Kennebunk and Kennebunkport. This study updated the former analyses for the 50 community submitted transects (performed by Sebago Technics in 2010 (Sebago Technics 2010a, 2010b, and 2010c) to apply a consistent approach for all transects within the county. Coastal engineering performed in 2013 in these 3 communities were largely based on the additional community data submitted to FEMA in 2009. This data provided newly established initial wave conditions for the transects developed from STWAVE, a two- dimensional wave transformation model, but used a different approach that resulted in non-deepwater wave conditions. In 2014, a Scientific Resolution Panel (SRP) ruled that a similar approach used in the communities of Scituate and Marshfield in Plymouth County, Massachusetts was not in compliance with the guidance in the Atlantic Ocean and Gulf of Mexico Coastal Guidelines Update (FEMA, 2007a) as it did not account for depth to wavelength criteria specified to identify deepwater wave conditions. For Task Order 15, STARR updated the former analyses with deepwater wave parameters and wave runup consistent with Appendix D “Guidance for Coastal Flooding Analyses and Mapping,” (FEMA 2003a) of the Guidelines and Specifications, as well as, the “Atlantic Ocean and Gulf of Mexico Coastal Guidelines Update,” (FEMA 2007a). This analysis includes transect numbers 79-128.

5.3.1 Total Stillwater Elevations The total stillwater elevations (stillwater including storm surge plus wave setup) for the 1% annual chance flood were determined for areas subject to coastal flooding. The models and methods that were used to determine storm surge and wave setup are listed in Table 15. The stillwater elevation that was used for each transect in coastal analyses is shown in Table 17, “Coastal Transect Parameters.”

Figure 8: 1% Annual Chance Total Stillwater Elevations for Coastal Areas [Not Applicable to this Flood Risk Project]

Storm Surge Statistics Tidal gages can be used instead of historic records of storms when the available tidal gage record for the area represents both the astronomical tide component and the storm surge component. As part of a study in York County in 2007, a review was performed between the gage record in Portland and the U.S. Army Corps of Engineers Tidal Flood Profiles for New England (1988). The analysis indicated that the Tidal Flood Profiles could be used if updated to the 1983-2001 tidal epoch.

The 10-percent, 2-percent, 1-percent, and 0.2-percent stillwater elevations for Updated Map Mod transects should be taken from the “Technical Support Data Notebook for

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Coastal Engineering Analysis for Flood Insurance Study Revision” (TSDN) report for York County (OCC, Inc. 2007).

Table 16: Tide Gage Analysis Specifics [Not Applicable to this Flood Risk Project]

Combined Riverine and Tidal Effects Riverine areas that were tidally influenced, the coastal backwater was extended inland until the stillwater elevation or the coastal flooding met another flood source (i.e., a riverine flood source) with an equal water-surface elevation.

Wave Setup Analysis Wave setup was computed through the methods and models listed in Table 15. For those coastal transects where a structure was located, documentation was gathered on the structure, and the wave setup against the coastal structure was also calculated. The oscillating component of wave setup, dynamic wave setup , was calculated for areas subject to wave runup hazards.

5.3.2 Waves The energy-based significant wave height (Hmo) and peak wave period (Tp) are used as inputs to wave setup and wave runup calculations and were calculated using the Steady-State Spectral Wave Model (STWAVE). STWAVE is a phased-averaged spectral wave model that simulates depth-induced wave refraction and shoaling, depth- and steepness-induced wave breaking, diffraction, wind-wave growth, and wave-wave interaction and white capping that redistribute and dissipate energy in a growing wave field. The model accepts a spectral form of the wave as an input condition and provides Hmo and Tp results over the gridded model domain.

STARR team developed STWAVE models for the southern coastline of York County, and the results were obtained from the model for the coastal flooding analysis in the City of Saco and the towns of Kittery, Ogunguit, Old Orchard Beach, Wells, and York.

STWAVE models were developed for the City of Biddeford and the towns of Kennebunk and Kennebunkport by Sebago Technics as part of their study in 2007. STARR team obtained the results from Sebago Technics models for the coastal flooding analysis in these communities (Sebago Technics 2010a, 2010b, 2010c). This analysis was updated by STARR in 2016 to account for deepwater wave conditions and wave runup. Wave model (Coastal State University 2007) was used to calculate the nearshore wave fields required for the addition of wave setup effects. Three nested grids were used to obtain sufficient nearshore resolution to represent the radiation stress gradients required as ADCIRC inputs. Radiation stress fields output from the inner grids are used by ADCIRC to estimate the contribution of breaking waves (wave setup effects) to the total Stillwater elevation.

5.3.3 Coastal Erosion A single storm episode can cause extensive erosion in coastal areas. Storm-induced erosion was evaluated to determine the modification to existing topography that is expected to be associated with flooding events. Erosion was evaluated using the

111 methods listed in Table 15. The Coastal Hazard Analysis Modeling Program CHAMP is a Microsoft (MS) Windows-interfaced Visual Basic language program that allows the user to enter data, perform coastal engineering analyses, view and tabulate results, and chart summary information for each representative transect along a coastline within a user-friendly graphical interface. With CHAMP, the user can import digital elevation data; perform storm-induced erosion treatments, wave height, and wave runup analyses; plot summary graphics of the results; and create summary tables and reports in a single environment. CHAMP version 2.0 (FEMA 2007b) was used to perform erosion analysis, run WHAFIS, and apply RUNUP 2.0 to transects without coastal structures. Application of CHAMP followed the instructions in the FEMA Guidelines and Specifications (FEMA 2007a) and the Coastal Hazard Analysis Modeling Program user’s guide found in the software documentation (FEMA 2007c).The post-event eroded profile was used for the subsequent transect-based onshore wave hazard analyses.

5.3.4 Wave Hazard Analyses Overland wave hazards were evaluated to determine the combined effects of ground elevation, vegetation, and physical features on overland wave propagation and wave runup. These analyses were performed at representative transects along all shorelines for which waves were expected to be present during the floods of the selected recurrence intervals. The results of these analyses were used to determine elevations for the 1% annual chance flood.

Transect locations were chosen with consideration given to the physical land characteristics as well as development type and density so that they would closely represent conditions in their locality. Additional consideration was given to changes in the total stillwater elevation. Transects were spaced close together in areas of complex topography and dense development or where total stillwater elevations varied. In areas having more uniform characteristics, transects were spaced at larger intervals. Transects shown in Figure 9, “Transect Location Map,” are also depicted on the FIRM. Table 17 provides the location, stillwater elevations, and starting wave conditions for each transect evaluated for overland wave hazards. In this table, “starting” indicates the parameter value at the beginning of the transect.

Wave Height Analysis Wave height analyses were performed to determine wave heights and corresponding wave crest elevations for the areas inundated by coastal flooding and subject to overland wave propagation hazards. Refer to Figure 6 for a schematic of a coastal transect evaluated for overland wave propagation hazards.

Wave heights and wave crest elevations were modeled using the methods and models listed in Table 15, “Summary of Coastal Analyses”.

Wave Runup Analysis Wave runup analyses were performed to determine the height and extent of runup beyond the limit of stillwater inundation for the 1% annual chance flood. Wave runup elevations were modeled using the methods and models listed in Table 15.

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Table 17: Coastal Transect Parameters

Starting Wave Conditions for Starting Stillwater Elevations (ft NAVD88) the 1% Annual Chance Significant Peak Wave Coastal Wave Height Period 10% Annual 4% Annual 2% Annual 1% Annual 0.2% Annual Flood Source Transect Hs (ft) Tp (sec) Chance Chance Chance Chance Chance Atlantic Ocean 001 1.6 7.7 8.2 * 8.8 9.2 9.8 Atlantic Ocean 002 7.5 10.0 8.2 * 8.8 9.2 9.8 Atlantic Ocean 003 7.5 10.0 8.2 * 8.8 9.2 9.8 Atlantic Ocean 004 1.6 7.9 8.2 * 8.8 9.2 9.8 Atlantic Ocean 005 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 006 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 007 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 008 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 009 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 010 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 011 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 012 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 013 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 014 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 015 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 016 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 017 29.9 11.4 8.2 * 8.8 9.2 9.8

* Not calculated for this Flood Risk Project

113 Table 17: Coastal Transect Parameters • continued

Starting Wave Conditions for Starting Stillwater Elevations (ft NAVD88) the 1% Annual Chance Significant Peak Wave Coastal Wave Height Period 10% Annual 4% Annual 2% Annual 1% Annual 0.2% Annual Flood Source Transect Hs (ft) Tp (sec) Chance Chance Chance Chance Chance Atlantic Ocean 018 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 019 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 020 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 021 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 022 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 023 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 024 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 025 23.0 11.6 8.2 * 8.8 9.2 9.8 Atlantic Ocean 026 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 027 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 028 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 029 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 030 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 031 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 032 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 033 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 034 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 035 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 036 29.9 11.4 8.2 * 8.8 9.2 9.8

* Not calculated for this Flood Risk Project

114 Table 17: Coastal Transect Parameters • continued

Starting Wave Conditions for Starting Stillwater Elevations (ft NAVD88) the 1% Annual Chance Significant Peak Wave Coastal Wave Height Period 10% Annual 4% Annual 2% Annual 1% Annual 0.2% Annual Flood Source Transect Hs (ft) Tp (sec) Chance Chance Chance Chance Chance Atlantic Ocean 037 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 038 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 039 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 040 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 041 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 042 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 043 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 044 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 045 22.0 11.3 8.2 * 8.8 9.2 9.8 Atlantic Ocean 046 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 047 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 048 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 049 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 050 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 051 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 052 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 053 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 054 29.9 11.4 8.2 * 8.8 9.2 9.8 Atlantic Ocean 055 29.9 11.4 7.9 * 8.5 8.9 9.5

* Not calculated for this Flood Risk Project

115 Table 17: Coastal Transect Parameters • continued Starting Wave Conditions for Starting Stillwater Elevations (ft NAVD88) the 1% Annual Chance Significant Peak Wave Coastal Wave Height Period 10% Annual 4% Annual 2% Annual 1% Annual 0.2% Annual Flood Source Transect Hs (ft) Tp (sec) Chance Chance Chance Chance Chance Atlantic Ocean 056 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 057 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 058 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 059 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 060 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 061 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 062 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 063 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 064 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 065 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 066 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 067 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 068 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 069 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 070 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 071 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 072 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 073 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 074 29.9 11.4 7.9 * 8.5 8.9 9.5 * Not calculated for this Flood Risk Project

116 Table 17: Coastal Transect Parameters • continued Starting Wave Conditions for Starting Stillwater Elevations (ft NAVD88) the 1% Annual Chance Significant Peak Wave Coastal Wave Height Period 10% Annual 4% Annual 2% Annual 1% Annual 0.2% Annual Flood Source Transect Hs (ft) Tp (sec) Chance Chance Chance Chance Chance Atlantic Ocean 075 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 076 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 077 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 078 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 079 21.3 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 080 21.3 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 081 21.3 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 082 21.3 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 083 21.3 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 084 21.3 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 085 21.3 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 086 21.3 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 087 21.3 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 088 21.3 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 089 21.3 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 090 21.3 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 091 21.3 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 092 21.3 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 093 21.3 11.1 7.9 * 8.5 8.9 9.5

* Not calculated for this Flood Risk Project

117 Table 17: Coastal Transect Parameters • continued

Starting Wave Conditions for Starting Stillwater Elevations (ft NAVD88) the 1% Annual Chance Significant Peak Wave Coastal Wave Height Period 10% Annual 4% Annual 2% Annual 1% Annual 0.2% Annual Flood Source Transect Hs (ft) Tp (sec) Chance Chance Chance Chance Chance Atlantic Ocean 094 21.3 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 095 21.3 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 096 21.3 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 097 21.3 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 098 6.5 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 099 6.5 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 100 6.5 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 101 21.3 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 102 7.5 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 103 21.3 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 104 21.3 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 105 21.3 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 106 21.3 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 107 21.3 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 108 21.3 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 109 21.3 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 110 21.3 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 111 22.9 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 112 22.9 11.1 7.9 * 8.5 8.9 9.5 * Not calculated for this Flood Risk Project

118 Table 17: Coastal Transect Parameters • continued Starting Wave Conditions for Starting Stillwater Elevations (ft NAVD88) the 1% Annual Chance Significant Peak Wave Coastal Wave Height Period 10% Annual 4% Annual 2% Annual 1% Annual 0.2% Annual Flood Source Transect Hs (ft) Tp (sec) Chance Chance Chance Chance Chance Atlantic Ocean 113 22.9 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 114 22.9 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 115 22.9 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 116 22.9 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 117 22.9 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 118 22.9 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 119 22.9 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 120 22.9 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 121 22.9 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 122 22.9 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 123 22.9 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 124 12.0 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 125 12.0 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 126 22.9 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 127 12.1 11.1 7.9 * 8.5 8.9 9.5 Atlantic Ocean 128 1.9 3.3 7.9 * 8.5 8.9 9.5 Atlantic Ocean 129 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 130 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 131 29.9 11.4 7.9 * 8.5 8.9 9.5 * Not calculated for this Flood Risk Project

119 Table 17: Coastal Transect Parameters • continued

Starting Wave Conditions for Starting Stillwater Elevations (ft NAVD88) the 1% Annual Chance Significant Peak Wave Coastal Wave Height Period 10% Annual 4% Annual 2% Annual 1% Annual 0.2% Annual Flood Source Transect Hs (ft) Tp (sec) Chance Chance Chance Chance Chance Atlantic Ocean 132 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 133 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 134 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 135 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 136 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 137 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 138 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 139 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 140 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 141 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 142 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 143 29.9 11.4 7.9 * 8.5 8.9 9.5 Atlantic Ocean 144 29.9 11.4 7.9 * 8.5 8.9 9.5 *Not calculated for this Flood Risk Project

120 ¨§¦95 £11 ¬«14 TOWN OF 4 «¬14 DAYTON TOWN OF 3 OLD ORCHARD «¬14 ¨§¦195 BEACH 2 1 «¬41

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TOWN OF SHEET 1 of 2 06 OGUNQUIT «¬3 F FIGURE 9

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I APPROXIMATE SCALE G FEDERAL EMERGENCY MANAGEMENT AGENCY 0 5 U Miles R

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1 (ALL JURISDICTIONS) TRANSECT LOCATION MAP

5.4 Alluvial Fan Analyses This section is not applicable to this Flood Risk Project.

Table 18: Summary of Alluvial Fan Analyses [Not Applicable to this Flood Risk Project]

Table 19: Results of Alluvial Fan Analyses [Not Applicable to this Flood Risk Project]

123