1. Demonstration Study to Evaluate Coastal Flood Hazards on Lake Erie ASFPM, San Antonio, TX May 22, 2012

2. Great Lakes Coastal Flood Study

3. Great Lakes Coastal Flood Study Overview  Current FIRMs are outdated due to the age of data and methodologies – many date to 1970s  Changes in NFIP policies and methodologies have since occurred, creating the need for an update  New methods have been developed GLCFS is first implementation Methods will be incorporated into official FEMA guidance  Study includes entire U.S. Great Lakes coastline

4. Great Lakes Guides & Standards  Great Lakes Guidelines & Standards issued for Public Review and Comment on May 8 th.  As part of the technical community, your review and comments are welcome.  60 day Comment period ends July 7 th  Check website for link to document: http://www.greatlakescoast.org/ or www.FEMA.gov http://www.greatlakescoast.org/ www.FEMA.gov

5.  First implementation of new methods  Expansive project reach: Covers five lakes over eight States and many counties Coordination of the efforts of many stakeholders and partners  Great Lakes are unlike other coastlines: Local lake levels vary Some Lakes have man made influences and controls to lake levels Ice cover impacts flood hazards Great Lakes Coastal Flood Study Challenges

6. Great Lakes Water Levels  Water levels have fluctuated throughout history  Winds and storms create dramatic, localized changes in levels in a very short period  Climate causes changes in water supply gradually  Human regulation activity also influences water levels Source: US Army Corps of Engineers

7. Great Lakes Water Levels

8. Seasonal Lake Levels  Water Levels vary 1- 3 ft annually

9. Western basin, comprising about one-fifth of lake, is very shallow with an average depth of 24 feet. Western basin is about 40 miles long. Central basin is both wider and deeper than the western basin and has maximum depth of approximately 90 feet and length of about 130 miles. Eastern basin is about 220 feet deep and 80 miles long. Lake Depths

10. Lake Erie Seiche

11. Ice Cover  Erie has history of completely icing over in winter months

12. Oblique Aerials

13.  Topographic LiDAR  NOAA NGDC Bathymetry  Combined Topo/bathy for a seamless DEM Data Sources

14. Storm Surge Model  ADCIRC/UNSWAN  789,750 nodes  Maximum mesh resolution at 60 meters (200 ft)

15. Storm Selection  20 water level gages/ 8 used for storm selection  20 storms per station based on max surge  51 WIS stations used to select top 20 storms based on wave heights.  Storms are filtered out by: removing duplicate storms maximizing individual storm effects over the entire lake ensuring various long term lake levels are accounted for  Resulted in a total of 157 storms for simulation for Lake Erie Top 20 Historical Storm Surges for Stations WIS Stations data (1956-1987)

16. Wave and Surge Modeling Wind & Pressure Fields  Storm identified using extreme value analysis of water level data for each gauge  Storm duration selected based on wave & wind fields of a given storm  Grid size 0.02 degree selected  Wind and pressure data files associated with storm date pulled out from CFSR data files or generated using Natural Neighborhood method  Wind and pressure files generated for given storm using FORTRAN routine by ERDC

17. Ice Field Generation  NOAA Ice Atlas use as data source Ice coverage files (.NIC/.CIS) during storm pulled out from Ice archive (GLERL)  Ice field generation routines provided by ERDC  data from 1960-2010

18. Simulation of Storm 12/12/2000  Wave Height (Hs)  Surge  Current  Ice Concentration Coupled Wave and Surge Modeling

19. Data storage

20. Erie County, PA Demonstration Project  RAMPP is conducting an early demonstration project for 20 miles of Erie County, PA shoreline  One of the first implementations of the new study methods ; precedes the remainder of the Great Lakes coastal counties  Test and refine the methodology and develop best practices, to inform the remainder of the GLCFS

21. Erie Area

22. Transect Overland Modeling  Transects laid out along coast – typically ½ to 1 mile apart, denser where needed.  Erosion – sandy and unconsolidated shorelines.  Runup – Response Method – Every identified historic storm is used  Overtopping  Overland Wave Propagation - Event Method – only single storm representing 1% storm.

23. Overland Wave Demonstration Project  Comparisons: Event based vs. response based at selected transects  WHAFIS and Wave Runup CSHORE model  Wave runup  Erosion  Wave setup  Overland waves.

24. Overland Wave Demonstration Project

26. Erosion  USACE CSHORE model Applies real physics Near-shore wave processes Cross-shore and along shore sediment transport Requires sediment grain size  Available data or estimated

27. Run-Up Modeling  USACE CSHORE model Figure D.3.5-5. Wave Runup Sketch Barrier Slope Breaker Depth Limit of Wave Runup Storm Still Water Level Source: FEMA, 2003

28. GeoCoastal Tools

29. Transect

30. Water level and Wave time series

31. Demo Transect

32. Water level and Wave time series

33. Response based Runup

34. Transect Model Results

35. Coastal Flood Hazard Mapping Coastal Hazard Workmaps

36. Overland Wave Demonstration Project  Demonstration project results: Will be presented to stakeholders for input Will inform level of effort required to complete analysis for each county Will identify any data gap needs Will inform the methodology for effectiveness May inform guidance needed in the G&S

37.  Study used to update FEMA FIRMs and FIS to reflect current flood risk  Develop Risk MAP tools for enhanced floodplain and risk management  Early stakeholder engagement allows a better understanding of FEMA goals in hazard risk management  Two-way communication between the Study Team and communities affected by the Study results is essential Great Lakes Coastal Flood Study Review

38. 3D Visualization

39. Outreach  Telling others gives your organization a voice!  Visit greatlakescoast.org for information and updatesgreatlakescoast.org  Contact us to become involved  Spread the word in your organization and community by: Link study info to your org’s website or social media Discuss study at your org’s next meeting Attend future events

40. Questions?