North Carolina North Carolina Neuse River Basin PlanNeuse River Basin Plan

Final Scoping MeetingsApril 23, 24, and 25, 2001

North CarolinaNorth CarolinaCooperating Technical Cooperating Technical State Flood Mapping State Flood Mapping Program OverviewProgram Overview

Purposes of the NFIPPurposes of the NFIP

1. Make flood insuranceavailable

2. Identify floodplainareas and flood risk zones

3. Provide framework for a community’s floodplain management ordinances

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

Importance of Updated Importance of Updated Flood Hazard InformationFlood Hazard Information

North Carolina’s North Carolina’s Flood Mapping Flood Mapping

ProgramProgram 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

Organization of the Organization of the CTS Flood Mapping CTS Flood Mapping

ProgramProgram

NC Center for Geographic Information

and Analysis

NCGeodetic Survey

NC Division of Emergency

Management

Federal Emergency Management Agency

OSBPM

John Dorman,Program Director/Chair

CTSCommittee

Abdul Rahmani,

Project Manager

State Floodplain Mapping

ContractorGreenhorne & O’Mara, Inc.

State Floodplain Mapping

ContractorWatershed

Concepts, Inc.

Rodger Durham,

Program Manager

Mapping Coordination Contractor

Dewberry & Davis LLC

Why North Carolina Is Why North Carolina Is Undertaking This Undertaking This

ProjectProject State’s vulnerability to hurricanes

and 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

Why North Carolina Is Why North Carolina Is Undertaking This Undertaking This

ProjectProject 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 updated

flood study for one county per year Many counties and communities lack

resources to take on this responsibility

Benefits of North Benefits of North Carolina’s CTS Carolina’s CTS

ProgramProgram 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

Program Program ComponentsComponents

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

Digital FIRMsDigital FIRMs

Digital FIRM=

Flood DataBase + Topography +

Digital FIRMsDigital 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’ by 10,000’ tiling scheme

Community Review and Community Review and Due ProcessDue Process

Preliminary FIRMs provided when the Neuse 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

Additional Benefits Additional Benefits of the CTS Programof 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

Neuse River BasinNeuse River Basin

Originates in north central Piedmont region of North Carolina in Person and Orange Counties, extends southeast through the Coastal Plain region, and eventually flows into Pamlico Sound

Third largest river basin in North Carolina, encompassing an area of approximately 6,200 square miles

Encompasses all or parts of 23 countiesand 78 municipalities

Scoping Phase for Scoping Phase for Neuse River BasinNeuse River Basin

The Scoping Phase determines: What areas are floodprone and need

flood hazard data developed Determine appropriate technical

method for developing up-to-date flood hazard data and establish priority level

How flood hazard data will be presented on FIRMs

State

State

FEMA

FEMA

KickoffMeeting with County/Local

Floodplain Administrators

MappingNeeds

Assessment

EffectiveFIS & FIRM Research

EvaluatePost-Floyd

Data

NCScoping

Database

Generate Initial

Scoping Package

InitialScoping Meetings

Develop Draft Basin Plans

Final Scoping Meetings

Finalize BasinPlans

Process for Scoping Six River Basinsin Eastern North Carolina

Prepare Delivery Orders& CTC

Mapping Activity

Agreements & Update

CTS Mapping

Agreement

Analysis and

Mapping

Step 1

Initial Research and Community

Coordination

Step 2

Initial Scoping Meeting

Step 3

Draft Basin Plans

Step 4

Final Scoping Meeting

Step 5

Final Basin Plans

SCOPING PRODUCTION

Questionnaire

Step 4 — Final Scoping Step 4 — Final Scoping MeetingMeeting

THIS IS WHERE WE ARE TODAY! All impacted counties and communities

invited Three separate Final Scoping Meetings:

April 23rd – Raleigh, NC April 24th – Goldsboro, NC April 25th – New Bern, NC

Draft Neuse River Basin plan presented Provides final opportunity for input

Step 5 — Final Basin PlanStep 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 Neuse River Basin, will develop proposals for the State

Neuse River Basin Plan will be finalized and notification sent to impacted counties and communities

Production phase will then begin

North Carolina North Carolina Neuse River Basin Neuse River Basin

MeetingMeeting

QQUESTIONS ON THE UESTIONS ON THE SCOPING PHASESCOPING PHASE

? ? ?? ? ?

Draft NeuseDraft NeuseRiver Basin PlanRiver 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

Detailed Study — Detailed Study — RiverineRiverine

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

Riverine Areas to be Riverine Areas to be Studied in DetailStudied in Detail

Riverine Areas to be Riverine Areas to be Studied in DetailStudied in Detail

(cont’d)

Detailed Study — Detailed Study — CoastalCoastal

This method produces the following: Floodplain mapping for areas along

open coast and embayments Designations as Zones AE or VE

RedelineationRedelineation

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

Proposed for all areas currently shown on effective FIRM as Zone

A1-30/AE or V1-30/VE and not being restudied

Approximate StudyApproximate 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.

Proposed for all areas currently shown on effective FIRM as Zone

A and not being restudied in detail.

Use of Effective Use of Effective InformationInformation

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 Neuse River Basin.

This method is not anticipated to be used for any communities in

the Neuse River Basin.

Going Beyond the Going Beyond the MinimumMinimum

Communities are encourgaged 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.

Community Mapping Community Mapping OptionsOptions

Community-adopted higher standards can be supported by optional map features shown digitally in a separate GIS layer, or possibly printed on the FIRM, or both.

Communities can have “customized” flood hazard data generated for their area through the NC Flood Mapping Program.

Community Mapping Community Mapping Options (continued)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

Community Mapping Community Mapping Options (continued)Options (continued)

Flood hazard data options: (continued) Areas within a community-adopted

“freeboard contours” (i.e., areas that would be inundated if floodwaters reached the freeboard level)

Guidance for Guidance for CommunitiesCommunities

The State will provide guidance to communties 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,

Higher Standards Higher Standards (continued)(continued)

State guidance: (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.

Schedule for FIRM Schedule for FIRM ProductionProduction

Schedule for FIRM Schedule for FIRM ProductionProduction

(cont’d)

North Carolina North Carolina Neuse River Basin Neuse River Basin

MeetingMeeting

QQUESTIONS ON THE UESTIONS ON THE

DRAFT BASIN PLANDRAFT BASIN PLAN

? ? ?? ? ?

North Carolina North Carolina Flood Mapping ProgramFlood Mapping Program

For More InformationFor More Information

Web Site: www.ncfloodmaps.comWeb Site: www.ncfloodmaps.com

FEMA Map Assistance: 1-877-336-2627FEMA Map Assistance: 1-877-336-2627

State POC: Rodger Durham (919) 715-State POC: Rodger Durham (919) 715-21272127