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North Carolina Pasquotank River Basin Plan

North Carolina Pasquotank River Basin Plan. Final Scoping Meetings May 17 and 18, 2001. North Carolina Cooperating Technical State Flood Mapping Program Overview. Purposes of the NFIP. 1. Make flood insurance available 2. Identify floodplain areas and flood risk zones

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North Carolina Pasquotank River Basin Plan

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  1. North Carolina Pasquotank River Basin Plan Final Scoping Meetings May 17 and 18, 2001

  2. North CarolinaCooperating Technical State Flood Mapping Program Overview

  3. Purposes of the NFIP 1. Make flood insuranceavailable 2. Identify floodplainareas and flood risk zones 3. Provide framework for a community’s floodplain management ordinances

  4. Importance of Updated Flood Hazard Information • With up-to-date flood hazard data: • Map users can make prudent siting, design, and flood insurance purchase decisions • Communities can administer sound floodplain management programs

  5. North Carolina’s Flood Mapping Program • Established to implement the Cooperating Technical State (CTS) Partnership with FEMA, signed September 15, 2000 • Ownership and responsibility for Flood Insurance Rate Maps (FIRMs) delegatedto State

  6. Organization of the CTS Flood Mapping Program

  7. Why North Carolina Is Undertaking This Project • State’s vulnerability to hurricanesand flooding • 14 federally declared disasters since 1989 • Hurricane Floyd damages = $3.5 billion • 4,117 uninsured/under-insured homes destroyed as result of Hurricane Floyd • Accurate, up-to-date flood hazard information crucial to protect livesand property

  8. Why North Carolina Is Undertaking This Project • Hurricane Floyd revealed flood hazard data and map limitations • Age of North Carolina FIRMS • 55% at least 10 years old • 75% at least 5 years old • FEMA’s mapping budget is finite • North Carolina receives only one updatedflood study per county per year • Many counties and communities lack resources to take on this responsibility

  9. Benefits of North Carolina’s CTS Program • Current, accurate data for sound siting and design decisions • Better floodplain management to reduce long-term flood losses • Updated data to alert at-risk property owners of the need for flood insurance • Faster, less expensive FIRM updates

  10. Program Components • Developing flood hazard studies through community mapping needs analysis (Scoping) • Acquiring high-resolution topographic data and accurate Digital Elevation Models (DEMs) • Conducting engineering studies • Generating countywide digital FIRMs (DFIRMs) • Designing and implementing state-of-the-art, dynamic IT infrastructure • Supporting real-time flood forecasting and inundation mapping capability

  11. + + Topography Flood Data Base Digital FIRM = Digital FIRMs

  12. Digital FIRMs • Digital FIRMs will be produced in a countywide format • Will depict all flood hazard data • FIRM panels will be consistent with the State land records’ 10,000’ x 10,000’ tiling scheme

  13. Community Review and Due Process • Preliminary FIRMs provided when the Pasquotank River Basin Study is complete • 90-day appeal period • Preliminary Countywide FIRMs provided when adjacent basin studies are complete • All appeals evaluated and resolved • Final Effective FIRMs provided and made available by the State on its Information Management System

  14. Additional Benefits of the CTS Program • Digital format to allow: • More efficient, precise flood risk determinations • Geographic Information System (GIS) analysis and planning • Online access 24 hours a day • DEMs will be useful for almost any engineering or planning application

  15. Pasquotank River Basin • Located in the northeast corner of North Carolina’s Coastal Plain region and covers approximately 3,700 square miles • Encompassed land area is low-lying with extensive open water; total distance of freshwater flooding sources is approximately 475 miles; total area of saltwater in the basin is approximately 868,800 acres • Includes 10 counties and 11 municipalities in North Carolina; population in the basin is approximately 97,000

  16. Scoping Phase for Pasquotank River Basin The Scoping Phase determines: • What areas are floodprone and need flood hazard data developed • Appropriate technical method for developing up-to-date flood hazard data and establishing priority level • How flood hazard data will be presented on FIRMs

  17. SCOPING PRODUCTION Step 1 Step 2 Step 3 Step 4 Step 5 Initial Research and Community Coordination Initial Scoping Meeting Draft Basin Plans Final Scoping Meeting Final Basin Plans State KickoffMeeting with County/Local Floodplain Administrators Questionnaire State Prepare Delivery Orders& CTC Mapping Activity Agreements & Update CTS Mapping Agreement Develop Draft Basin Plans MappingNeeds Assessment Generate Initial Scoping Package NCScoping Database InitialScoping Meetings Final Scoping Meetings Finalize BasinPlans Analysis and Mapping FEMA EffectiveFIS & FIRM Research FEMA Process for Scoping Six River Basinsin Eastern North Carolina EvaluatePost-FloydData

  18. Step 4 — Final Scoping Meeting THIS IS WHERE WE ARE TODAY! • All impacted counties and communities invited • Two separate Final Scoping Meetings: • May 17th – Elizabeth City, North Carolina • May 18th – Manteo, North Carolina • Draft Pasquotank River Basin Plan presented • Provides final opportunity for input

  19. Step 5 — Final Basin Plan • Draft Basin Plan may be revised following the Final Scoping Meeting • Watershed Concepts, the State’s Floodplain Mapping Contractor for the Pasquotank River Basin, will develop proposals for the State • Pasquotank River Basin Plan will be finalized and notification sent to impacted counties and communities • Production phase will then begin

  20. North Carolina Pasquotank River Basin Meeting QUESTIONS ON THE SCOPING PHASE ? ? ?

  21. Draft PasquotankRiver Basin Plan • Summarizes scoping phase • Outlines how base maps and topography will be acquired • Proposes engineering methods by which each flooding source reach will be studied • Describes the process and schedule for completing the map production

  22. Detailed Study — Coastal This method produces the following: • Floodplain mapping for areas alongopen coast and embayments • Designations as Zones AE or VE

  23. Detailed Study — Riverine This method requires the following: • Digital Elevation Data • Field Surveys • Channel bathymetry • Bridge/culvert opening geometry • Channel and floodplain characteristics • Detailed Hydrologic and Hydraulic Analyses • 10%, 2%, 1%, and 0.2% annual chance flood elevations and boundaries identified (Zone AE) • Floodways delineated

  24. Riverine Areas to be Studied in Detail

  25. Redelineation This method requires the following: • Digital Elevation Data • Effective FIS flood elevations Proposed for all areas currently shown on effective FIRM as Zone A1-30/AE or V1-30/VE, and not being restudied

  26. Approximate Study This method requires the following: • Digital Elevation Data • Delineation of 1% annual chance floodplain boundaries using approximate methods • May include collection and use of field-collected topographic data or bridge/culvert data if plans are not readily available Proposed for all areas currently shown on effective FIRM as Zone A and not being restudied in detail.

  27. Use of Effective Information • This method involves no new analyses or floodplain mapping • Effective FIS and FIRM data are digitized and fitted to updated base map This method is not anticipated to be used for any communities in the Pasquotank River Basin.

  28. Going Beyond the Minimum • Communities are encouraged to manage floodplain development according to standards that are more stringent than FEMA minimums. • Benefits of adopting higher standards: • Reduced risk to lives and property; and • Lowered flood insurance premiums, including possible Community Rating System discounts.

  29. Community Mapping Options • Community-adopted higher standards can be supported by optional map features shown digitally in a separate GIS layer, printed on the FIRM, or both. • Communities can have “customized” flood hazard data generated for their area through the NC Flood Mapping Program.

  30. Community Mapping Options (continued) • Customized flood hazard data options: • 1% annual chance floodplains and elevations based on future land use conditions (in addition to existing conditions data); • Wider floodways based on a reduced surcharge value (i.e., less than the 1-foot FEMA maximum); and • Areas within a community-adopted “freeboard contours” (i.e., areas that would be inundated if floodwaters reached the freeboard level)

  31. Guidance for Communities • The State will provide guidance to communities on: • Selecting higher standards options that meet community needs; • Data the communities must provide (land use plan, etc.); • Potential community cost-sharing to cover increased mapping costs;

  32. Guidance for Communities (continued) • Model Flood Hazard Damage Prevention ordinances that reflect enhanced floodplain management standards; and • Outreach programs for citizens and businesses affected by newly mapped flood hazard areas or updated ordinances.

  33. Schedule for FIRM Production

  34. North Carolina Pasquotank River Basin Meeting QUESTIONS ON THE DRAFT BASIN PLAN ? ? ?

  35. North Carolina Flood Mapping Program For More Information Web Site: www.ncfloodmaps.com FEMA Map Assistance: 1-877-336-2627 State POC: Rodger Durham (919) 715-2127

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