Presentation to the Association of State Floodplain Managers Interagency Partnering for Flood Forecast Inundation Maps Brian Rast, PE, CFM, PMP Lead Silver Jackets Coordinator, Kansas and Missouri Kris Lander, PE, CFM Hydrologist June 4, 2015 US Army Corps of Engineers
Day Curve the benefits Risk informed individuals can drive the stage damage curve to the left to reduce damages and flood fight costs. 2
Outline Describe what a FFIM is Show where FFIMs are Explain the development of FFIMs Actual application to flooding Challenges Conclusion Highlight the interagency nature of this valuable tool. 3
Description of FFIMs 4
Flood Forecast Inundation Maps (FFIMs) are interactive web page shows the spatial extent of possible or expected flooding in a given area. It can be used to show if roadways and structures will be impacted by floodwaters. At the limited number of forecast locations where inundation maps are currently available, this web page is accessed by clicking on the inundation mapping tab on the hydrograph web page. In collaboration with partners, this product will be expanded to new locations. A webviewer Flood extents Predicted stage Historic events 5
Misc points Non-regulatory product Continuum of flood risks Action specific to flood categories 6
Where To Find FFIMs 7
NOAA NWS Flood Inundation Mapping (Sep 2014) http://water.weather.gov/ahps/inundation.php 8
Developing a FFIM 9
Development of a FFIM Criteria include Watersheds over 100 square miles Amount of warning time Risk situations where development is at the extreme downstream end of the basin Development potential of new structures in the floodplain management could be done well using the inundation maps 10
Selecting Sites Project Basin Area (square miles) Warning Time Notes Wildcat Creek 99 4 to 8 hours Informs evacuation timing Cross Creek 178 6 to10 hours Informs evacuation timing Big Blue River 9,733 Several days Clarifies level of protection, operationalizes FRM Missouri River Varies Several days to a week Informs flood fighting and saves costs Little Blue River 225 12 to 16 hours See Big Blue Roubidoux Creek 290 14 to 18 hours Informs evacuation 11 timing
Wildcat Creek Watershed 99 Square Miles 12
Wildcat Creek Project Limits http://water.weather.gov/ahps2/inundation/inundation_google.php?gage=mwck1 13
Static Map Book GIF 14
Perfect Storm of Resources HEC-RAS USACE County, State Division of Water Resources (DWR), FEMA LiDAR County, DWR, FEMA High water marks. 2011 flood Interest. Active public involvement 15
Using the FFIM Webviewer 16
17 Forecasted flood stages have more meaning when linked to a visual such as this Stakeholders can now quickly see and understand the immediate consequences of the stage (boxed in red) shown with this visualization. Maps associated with the selected stage (and elevation) (see yellow arrow) pop up immediately and the numbers are highlighted in yellow The viewer used is Google Maps
18 The variety of tools on the webpage can help any stakeholder understand their flood risks better Inset, including Historical Crests, will be visible for users to relate past flooding to current forecast Depth grids are also available, showing water depth associated with any inundation map
Public Understanding NWS flood category color scheming is a consistent tool extended to describe the level of flooding. Extensive inundation of structures and roads. Significant evacuations of people and property. Some inundation of structures and roads near stream some evacuations of people and property. Minimal or no property damage, but possibly some public threat. River or stream level approaching flood stage. River or stream level below flood stage. 19
Forecast Hydrograph 20
Floodway Display (red) 21
Base Flood Display (gray) 22
Application to Flooding 23
Flood Response in 2011 24
Hazard Mitigation Action 25
Hazard Mitigation Action 26 26
Challenges New rating curves Large rivers Sediment laden New sites without gages Flat topography Levees Stakeholders still have to make a decision and act 27
Community Roles Emergency managers Cities Counties Emergency responders Public Works Planning / Engineering / NFIP floodplain administrator Weather Forecast Office 28
CONCLUSION 29
Why Should We Consider This a Valuable Tool for Reducing Nations Susceptibility to Flood Damages? Visual for where flooding will happen Link between rainfall forecasts and coming flood levels Knowledge of when to flood fight, preventing costly, unnecessary efforts for preparedness Mechanism for pursuing public understanding of flood risks, considering whole floodplain Tool for risk informed decision making All-the-time, continuous communication (available 24 hours/day-7 days/week) Quality tool to achieve public understanding of flood risks Interagency effort that leverages existing tools and abilities of multiple agencies with roles in managing flood risks Flood map that does not limit risk informed decision making process to 1% event (goes beyond base flood, commonly depended on by the public) 30
Find out more U.S. Army Corps of Engineers http://www.usace.army.mil http://www.iwr.usace.army.mil/nfrmp/state Brian Rast, Project Manager Kris Lander, Hydrologist 816-389-3337, Brian.T.Rast@usace.army.mil 816-268-3124, Kris.Lander@noaa.gov National Weather Service Advanced Hydrologic Prediction Service (AHPS) http://water.weather.gov http://water.weather.gov/ahps/inundation.php http://www.youtube.com/watch?v=rtmqgckxgp4 31
QUESTIONS 32
Thank you for your time 33
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ADDITIONAL SLIDES FOR USE IN Q and A NOTE: To reduce file size of this PPTX, these slides may be deleted, if need be. 35
Interagency FFIM Projects 3 1 4 2 5 7 6 Point Descriptions: # Current # Pending # Future 36
Cross Creek http://water.weather.gov/ahps2/inundation/inundation_google.php?gage=rssk1 178 Square Miles 37
Static Map Book - GIF 38
Missouri River-2011 Flood 2011 Leavenworth Parkville 39
Missouri River-Flood Forecast Inundation Map RM 410 RM 400 Project Area River Miles (RM) 377 to 398 RM 390 RM 380 40
Missouri River-Flood Forecast Inundation Map Missouri River-Flood Forecast Inundation Map FOR MORE INFORMATION: http://water.weather.gov/ahps2/inundation/inundation_google.php?gage=levk1 AND http://www.nfrmp.us/state/missriverpilot.cfm Documented levee, shown inundated (left) 41
Missouri River-Parkville, MO Some communities connect directly with the river without a levee, and they protect that viewshed. Preserving this valued viewshed, in the 2011 flooding in Parkville called for setup of this temporary portadam, as well as sand bags. 42
Missouri River-Parkville, MO Some communities like to connect directly with the river without a levee, and they protect that viewshed 2011 flooding in Parkville called for setup of this portadam 43
Big Blue and Kansas Rivers Confluence Big Blue Watershed Largest tributary in Kansas River Basin Tuttle Creek Dam built in 1962 Manhattan Levee built in 1963 9,733 Square Miles First FEMA Risk MAP in Kansas 44
Big Blue and Kansas Rivers Confluence 45
Big Blue and Kansas Rivers Confluence Public will see outflows in terms of inundation maps. Tuttle Creek Dam OPERATIONALIZING FLOOD RISK MANAGEMENT In 1993 flooding, the community realized the need to better understand risks, especially what the Corps dam and levee can offer to reduce risks. Manhattan Levee RISK COMMUNICATION: Non-breach inundation (or extreme overflow events) are as important to understand as FEMA physical map revisions. 46
Big Blue and Kansas Rivers Confluence 47
Little Blue River BLUE SPRINGS LAKE LONGVIEW LAKE 225 Square Miles N 48
Roubidoux Creek Waynesville 290 Square Miles N 49