Sea Level Rise and the NFIP

Transcription

1 Cheryl A Johnson, PE, CFM, PMP March 26, 2014

2 Sea-level rise and the likely increase in hurricane intensity and associated storm surge will be among the most serious consequences of climate change 2

3 2013 IPCC Sea Level Rise Estimates 3

4 Tools Corps of Engineers Sea Level Rise Calculator RSLC Relative Sea Level Change 4

5 Which Scenario Should be Used? Lower rise scenarios: where there is a high tolerance for risk Projects with a short lifespan Planning areas with flexibility to make changes in the near-term These scenarios primarily address ocean warming with no major contributions from ice sheet melting Higher-rise scenarios: where there is a low tolerance for risk Projects with long lifespan Where losses would be catastrophic Where there is limited flexibility to adapt in the nearor long-term These scenarios primarily address both ocean warming and contributions to sea levels from melting ice sheets 5

6 Tools NOAA Digital Coast SLR Viewer 6

7 SLR Predictions - Not the Whole Story When water depths increase wave heights increase Rough Rules of Thumb (at the shoreline) 1: The maximum wave height is 0.78 times the local water depth. 2: 70% of the wave height (not 50%) lies above the mean water level. 3: Max BFE = Surge depth + (Surge depth*0.78*0.70) = Surge depth * : BFE increase (at the shore) = SLR * *h h=0.78*d Max BFE = 1.55*d d SWEL

8 Impact of Climate Change and Population Growth on the NFIP through 2100 Released during ASFPM 2013 Required by GAO 8

9 Incorporated SLR, Waves, Hurricane Frequency & Erosion 9

10 Other Tools USGS Coastal Erosion Prediction Tool Can be accessed from NOAA Digital Coast 10

11 FEMA s Sea Level Rise Pilot Projects Study areas: Hillsborough and Pinellas Counties, FL San Francisco County, CA Goals: Work closely with coastal communities to produce SLR information for advisory purposes - nonregulatory products Looking for cost effective way to estimate SLR effects for rest of the US. 11

12 BW12 - SEC Future Conditions (d) FUTURE CONDITIONS RISK ASSESSMENT AND MODELING REPORT. (1) IN GENERAL. The Council shall consult with scientists and technical experts, other Federal agencies, States, and local communities to (A) develop recommendations on how to (i) ensure that flood insurance rate maps incorporate the best available climate science to assess flood risks; and (ii) ensure that the Federal Emergency Management Agency uses the best available methodology to consider the impact of (I) the rise in the sea level; and (II) future development on flood risk; 12

13 BW12 SEC NATIONAL FLOOD MAPPING (3) OTHER INCLUSIONS. In updating maps under this section, the Administrator shall include (A) (D) any relevant information or data of the National Oceanic and Atmospheric Administration and the United States Geological Survey relating to the best available science regarding future changes in sea levels, precipitation, and intensity of hurricanes; and (E) any other relevant information as may be recommended by the Technical Mapping Advisory Committee. 13

14 CRS & Climate Change There are specific Activity elements within CRS which relate to Climate Change. Activity 300 series (Public Outreach) 320: Map Information Provide information to the public about areas susceptible to climate change/sea level rise 340: Hazard Disclosure Advise homebuyers of properties located in areas susceptible to climate change/sea level rise Activity 400 series (Mapping and Regulations) 410: Floodplain mapping Community regulates floodplains taking into account future conditions including sea level rise 450 Stormwater Management Taking into account future conditions Activity 500 series (Flood damage reduction) 510: Floodplain Management Plan Address future flood problems which may arise out of climate change/sea level rise conditions. Class No. of Communities Georgia CRS Community Classes as of May

15 Grants Benefit Cost Analysis and SLR Flood Damages Flood depths = flood elevations minus FFE Flood Elevations (10-, 50-, 100-, 500- years) First Floor Elevation (FFE) 15

16 Recently released Guidance on BCA and SLR Incorporating Sea Level Rise (SLR) into Hazard Mitigation Assistance (HMA) Benefit Cost Analysis Frequently Asked Questions (FAQs) Written materials and training to help applicants are available at costanalysis. FEMA does not mandate the inclusion of SLR for HMA project applications. The state or local community may use SLR to consider future conditions in mitigating future flood risk. 16

17 Future Non-Regulatory Products (on the drawing board) Coastal USA 17

18 Areas Affected by Increased Coastal Inundation Highlights areas that would be inundated if water levels increased by 1, 2, or 3 ft (or other userdefined increase) Typically created for the 1% annual chance flood, but could be done for other flood events

19 FEMA CLIMATE CHANGE ADAPTATION POLICY 1. To enhance climate research, monitoring, and adaptation capabilities, FEMA will continue to establish partnerships with other agencies and organizations that possess climate science and climate change adaptation expertise 2. FEMA will continue to study the impacts of climate change on the National Flood Insurance Program (NFIP) and incorporate climate change considerations in the NFIP reform effort. 3. FEMA will evaluate how climate change considerations can be incorporated into grant investment strategies with specific focus on infrastructure and evaluation methodologies or tools such as benefit/cost analysis. 4. FEMA will seek to understand how climate change will impact local communities and engage them in addressing those impacts. 5. FEMA will promote building standards and practices, both within FEMA programs and in general, that consider the future impacts of climate change. 6. Through partnerships with the climate science community, FEMA will evaluate the potential impact climate change may have on existing risk data and the corresponding implications for Threat Hazard Identification Risk Assessment (THIRA) development and operational planning. 7. FEMA will continue to pursue a flexible, scalable, well equipped, and well trained workforce that is educated about the potential impacts of climate change. 19

20 Questions? Thanks to Mark Crowell and Tucker Mahoney for their input