Bucks County, PA Flood Risk Review Meeting. November 2014

Transcription

1 Bucks County, PA Flood Risk Review Meeting November 2014

2 Agenda for Today Risk MAP Program overview Overview of non-regulatory Flood Risk Products and datasets Discuss mitigation action Technical overview of new flood studies and mapping Bucks County flood study timeline Levees Work Session Review of work maps Answer Questions 2

3 Introductions FEMA Region III Robert Pierson Project Officer RAMPP Kim Dunn, P.E., CFM Project Manager 3

4 FEMA s Risk MAP Program Risk Mapping, Assessment and Planning Builds on Map Mod digitized Flood Insurance Rate Map (FIRM) efforts Will deliver quality data that increase public awareness and can lead to action that reduces risk to life and property. Watershed approach Regulatory Products: Flood Insurance Study (FIS) and FIRM (flood study updates) New Non-Regulatory Products and Datasets Mapping Assessment Planning 4

5 Why We re Doing This: Hazard Mitigation Hazard Mitigation is defined as any sustained action taken to reduce or eliminate long-term risk to life and property from hazards FEMA encourages local governments to develop Hazard Mitigation Plans To increase public and political support and commitment for mitigation To be eligible for Hazard Mitigation Assistance grants Use new Risk MAP information to update your Hazard Mitigation Plan 5

6 Program Product Comparisons Traditional Regulatory Products DFIRM Database Products used for floodplain management and insurance purposes as part of the National Flood Insurance Program (NFIP) Map Modernization 6

7 Program Product Comparisons Non-Regulatory Flood Risk Products DFIRM Database RiskMAP Use for Flood Risk Mitigation Planning Map Modernization 7

8 Non-Regulatory Flood Risk Products and Datasets Flood Risk Products Flood Risk Report Flood Risk Database Flood Risk Map Flood Risk Datasets Changes Since Last FIRM Depth Grids Flood Risk Assessment (refined Hazus analysis) Flood Risk Products help communities: Gain a better understanding of flood risk and its potential impact on communities and individuals Take proper mitigation actions to reduce this risk 8

9 Using Changes Since Last FIRM for Identifying Actions Changes Since Last FIRM Communities and homeowners can use this to identify the impacts of new maps on the regulatory Special Flood Hazard Area (SFHA) Also reveals new areas that may need mitigation actions either for existing assets or for future planning 9

10 Using Depth and Analysis Grids for Identifying Actions Depth and Analysis Grids Better information on depth and percent chance of flooding More information on multiple frequency (10, 50, 100, 500 year) flood events These provide enhanced data to develop a more accurate Benefit Cost Analysis (BCA) for mitigation projects, a big step towards implementation 10

11 Using Flood Risk Assessment for Identifying Actions Flood Risk Assessment Identifies areas of higher flood risk by census block 1% Chance Risk (100-yr) Quantifies potential future flood losses to existing structures Improves ability to identify areas that would benefit from higher building code requirements Supports mitigation plan updates and disaster recovery planning through improved risk quantification 11

12 Products to Help Identify Potential Mitigation Actions 12

13 Hazard Mitigation Builds Sustainable, Resilient Communities RESILIENT tending to recover from or adjust easily to misfortune or change SUSTAIN from Latin sustinēre to hold up Synonyms: nourish, nurture A Community that plans for and mitigates against natural disasters is Resilient and more Sustainable: Economically businesses reopen more quickly Socially daily lives not as disrupted and stressed Environmentally - better functioning ecosystems with restored biodiversity Weebles Wobble but they don t fall down 13

14 Hazard Mitigation Planning Risk MAP and Mitigation Planning Refer to the Plan & Keep it Current Coordinated and participative Planning Process Mitigation Planning Cycle Identify hazards that can affect the jurisdiction Local hazard mitigation plans must be updated every five (5) years. Use new Risk MAP information to update local HMP. Flood Hazard Profile Risk Assessment Mitigation Strategy Adopt the plan and implement the mitigation strategy Assess the risks from these hazards Develop strategy to mitigate the risks 14

15 Categories of Flood Mitigation Activities 15

16 Possible Mitigation Activities 1 to 2 foot of freeboard for new structures. Cumulative substantial improvement clause. List of County owned buildings that have flood risk. Acquisition of flood prone structures. County drought plan. County GIS system. Updated weather tracking equipment. Stream bank stabilization projects Identified sanitary sewer mains vulnerable to erosion from flood Annual cleaning of streams and stormwater management ponds. Adopted a wellhead protection ordinance. Vulnerability assessment of water and wastewater infrastructure. Elevate, move and acquire flood damaged structures. Identify vulnerable critical facilities. Implement mitigation measures for repetitive loss properties. Require elevation of new structures and substantially improved structures. Restore stream channels 16

17 Recommended Higher Standards 1-2 feet of freeboard Restrictions on hazardous material storage Regulated high risk land uses (e.g. manufactured homes/critical infrastructure) 50 foot Setbacks/ Buffers Conservation/open space area Cumulative Substantial Damage/Substantial Improvement Lower threshold for Substantial Damage Subdivision design triggering flood study (5 lots or 5 acres, whichever is lesser) Prohibitions SFHA development Manufactured homes Fill Community Identified Flood Areas 17

18 Ways to take Action Floodplain Management Ordinances Higher building standards Community Rating System (CRS) Reduces flood insurance premiums Technical assistance Federal agencies and professional associations Grants for Mitigation Projects FEMA: HMGP Other Federal Agency grants: HUD/CDBG 18

19 Community Development Know Your line Initiative -High Water Marks Residential/commercial density in the floodplain Location/inundation area of historic events Total properties with insurance policies and as a percentage of the population Areas of increasing population growth Areas requiring protection 19

20 Emergency Management Accessibility to at risk areas, from critical facilities Industrial/Manufacturing plants in the floodplain Vulnerable populations Characteristics which make communities more/less vulnerable to flood risk 20

21 Discussion (during work session) We want to hear from you! What other mitigation plans and projects are there? Do any of the Risk MAP products make sense for your community? What are your community s concerns? How can we (both FEMA and you) communicate risk within your community and increase resilience from floods? 21

22 Flood Study Update Kim Dunn RAMPP 22

23 New Flood Study 23

24 New Detailed Study (Zone AE) All coastal/tidal portions of the Delaware River Black Ditch Cooks Run Croydon Run Croydon Tributary Ironworks Creek Lahaska Creek Martins Creek Mill Creek No. 1 Newtown Creek North Branch Neshaminy Creek Tributary D to Delaware River Tributary No. 1 of Martins Creek Tributary No. 2 of Martins Creek Tributary No. 3 of Martins Creek Tributary to West Branch Neshaminy Creek West Branch Neshaminy Creek 24

25 Coastal/Tidal Mapping 25

26 Delaware Bay Surge Differences Difference between updated and published 100-yr SWELs (ft) (Updated published) Orange: 1-2 ft higher Green: Less than 1 ft change Blue: 1-3 ft lower 26

27 Methods of Riverine Restudy o Hydrology Act 167 HEC-HMS model o Supplemented with additional monitoring points, more detailed routing, and other refinements o Some locations used regression equations, or effective hydrology if that better reflected field conditions/historic information o Hydraulics- overbank areas LiDAR o Channel modeled from field measurements o Structures- modeled from field measurements, supplemented with local data as provided 27

28 Enhanced Study Streams Overbank geometry from LiDAR Bridges and culverts modeled from field measurements Floodway modeled Base Flood Elevations (BFEs) shown on FIRM 28

29 Work Session Computer stations available for viewing draft floodplain mapping Link to online maps: Answer questions Talk about mitigation actions in your community 29

30 Workmap symbology Legend Streams Roads Municipal Boundaries FLOODWAY 0.2 PCT ANNUAL CHANCE FLOOD HAZARD A AE AO X PROTECTED BY LEVEE Floodplain Outline 30

31 Project Timeline Robert Pierson, Project Lead, FEMA Region III 31

32 Project Timeline for Bucks County Neshaminy Discovery Meeting June/July 2011 Previous Countywide effective date: 3/16/2015 Anticipated Preliminary for Neshaminy and Coastal : March 2015 Community Coordination Meeting: Spring 2015 Receive and address community comments (typically 30 days after CC0 Meeting) 90 Day Appeals period starts after second newspaper publication date of proposed Flood Hazard Determination 32

33 Project Timeline for Bucks County Non-regulatory products developed (late summer 2015) Finalize FIRMs/FIS to address any comments or appeals Letter of Final Determination (LFD) date occurs after appeals are addressed (early 2016) Initiates the 6-month ordinance adoption/compliance period Effective Date 6 months after LFD date and typically at least 15 months after preliminary date (Early 2015) 33

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