Transcript Slide 1
Cooperative Efforts in Nashville Flood Preparedness Jamie G. James, P.E. Water Resources Section Nashville District, USACE July 2011 US Army Corps of Engineers BUILDING STRONG® In May 2010 portions of Tennessee experienced flooding of unprecedented magnitude. Damage was widespread in the region, and the city of Nashville was particularly hard-hit. Public agencies scrambled to stay ahead of the disaster and prevent more severe flooding and loss of life. BUILDING STRONG® For Comparison: Recorded Floods at Nashville 70 60 50 40 Stage @ Nashville 30 20 10 2010 1984 1975 1927 1793 0 BUILDING STRONG® Cumberland River in Nashville May 2010 Flood Inundation Downtown Pennington Bend/Opryland BUILDING STRONG® In The Beginning: The Nashville work began as a result of realized shortcomings during the flood of May 2010. ► Communication Between Agencies ► Understanding Data and Wider Implications ► Flood Warning and Response All were determined to learn and improve readiness. Discussions began in August 2010 ► Metro Nashville Government ► Nashville District, USACE ► National Weather Service ► U.S. Geological Survey BUILDING STRONG® The Concept: Work as a broad-based team to a common goal. Control the things under our control. Support Metro EMS and leaders. ► Prevent loss of life, reduce damage Use each agency’s strengths. ► ► ► ► USACE – Hydrologic and hydraulic modeling Metro – GIS mapping and automation NWS – Flood warning USGS – Gaging and data Develop products & applications to provide Metro officials with timely information. BUILDING STRONG® Challenges Ongoing national level efforts to organize (IWRSS), but the framework had not been set. This is one of the first-of-its-type efforts on this scale. Scaling the scope of work . ► Needs, Time, Budget Ensuring a common understanding of the goals, technical abilities and products. BUILDING STRONG® Opportunities We could work within the regulations of the respective agencies to craft a product that was tailored to Nashville. Previous work around the streams and gaging network gave us a head start. BUILDING STRONG® Project Team Nashville District Metro Nashville National Weather Service U.S. Geologic Survey Study Manager Team Leaders Local Staff Local Staff 5 Engineers Stormwater Division GIS Specialist Watershed Advisors Technicians AMEC Interest and Support of Higher Organizational Levels BUILDING STRONG® Process Bi-weekly meetings to discuss progress and issues that arose. Constant communication regarding technical issues. Concentrated on Six Streams in the first phase: Cumberland River, Harpeth River, Mill Creek, Richland Creek, Browns Creek, Whites Creek. Keep the scope manageable within the time and budget constraints. We could always do more later. BUILDING STRONG® Goals Develop products that will provide Metro Emergency Services and decision makers with the capability to estimate flooding impacts in time to take early action. Look at flooding extent and timing. Effectively utilize limited resources to greatest effect during an emergency. Leverage local and federal dollars to provide the best capability possible, and build upon that later. BUILDING STRONG® Study Area BUILDING STRONG® Increasing Understanding: Cumberland River Stages Referenced from the Nashville Gage (Datum, 368.1) Based on May 2010 Profiles Depicts corresponding stages at other locations for referenced stages at the Nashville Gage. 65.0 60.0 55.0 50.0 45.0 Major 40.0 Moderate 35.0 Flood Action 30.0 No Action OHP Tailwater K.R. Harrington U/S Lock Two Rd Briley @ Pennington D/s Opry Mills Omohundro Nashville Gage Titans Stadium U/S Metro Cen D/S Metro Cen Harpeth Valley UD 25.0 BUILDING STRONG® Added Functions: Additional Gages on the Cumberland River and Mill Creek (USGS and Metro). Review of Forecast Points and Flood Warning Levels (NWS and Metro). Watershed Advisors for Each Stream (Metro). Flood Inundation GIS Layers for Each Stream Tied to Forecast Stages (USACE and Metro). Watershed Advisors Guides for each stream (AMEC). BUILDING STRONG® Nashville District Work Modeling and Mapping of the Six Streams for Metro GIS. ► Cumberland River, Harpeth River ► Mill Creek, Browns Creek, Richland Creek, Whites Creek Utilization of Available Geospatial Data (GeoHMS and GeoRAS, ArcMap). Model Multiple Storms to Prepare Inundation Layers. Provide AMEC with model results and timing for use in Watershed Advisors Guides. BUILDING STRONG® Nashville District Work (2) There were existing models for the Cumberland River, Mill Creek and Richland Creek. ► Updated/calibrated to meet the needs of the study. Utilization of available geospatial data (GeoHMS and GeoRAS, ArcMap, DEM). We prepared HMS and RAS models of the Harpeth River, Whites Creek and Browns Creek basins. ► Calibrated to known events and May 2010 where possible. ► Historic records and current high water marks. BUILDING STRONG® Nashville District Work (3) Modeled multiple storms to prepare inundation layers. ► HEC-HMS • • • • Used GEO-HMS to collect basin data Calibrated to historic rainfall 1-11 inch, 24-hour rainfall Type II distribution ► HEC-RAS • • • • Used GEO-RAS to collect cross section and alignment data Calibrated to historic floods Compared to historic HEC-2 and RAS models Inventoried bridges in the field and obtained TDOT plans where possible • Steady flow BUILDING STRONG® Nashville Flood Preparedness Inundation Products BUILDING STRONG® Results Additional stream gages allow Metro to monitor river conditions at critical infrastructure. New GIS layers provide Metro emergency personnel with inundation approximations tied to forecasts, helping to allocate resources and assist with timely evacuations. Metro GIS Specialists developed an interactive tool to illustrate inundation based on forecasts and layers. ► Public access will be determined by Metro. Watershed Advisors’ Guides provide information to help stay ahead of the flood. Phase II is underway. The flood preparedness tools will continue to evolve. ► ► Flood Damage Analysis HEC-RTS Phase III is being planned. BUILDING STRONG® HEC-RTS (Real-Time Simulation) BUILDING STRONG® HEC-RTS Provides a real-time simulation capability. RTS is proposed for the Cheatham Reach of the Cumberland River, which includes Nashville. Joins the hydrologic and hydraulic models to allow simulations of basin rainfall response and estimation of stages at the flow prediction points identified in the model. Prepared by USACE for Metro, to be reviewed by, and made available to, NWS. Scoping meeting was July 19. Delivery is planned for next spring. BUILDING STRONG® How can these efforts be applied in other locations? One product does not fit every community. We developed this work with scalability, portability and adaptability in mind. If a flood-prone community has GIS capability, we can duplicate this work for their streams, on their system. If a flood-prone community does not have GIS, we can create paper maps to illustrate the flood inundation levels. In either case, new gages can be installed to monitor streams near critical infrastructure. ► Automated warnings can be applied. A Flood Warning and Emergency Evacuation Plan can be developed to help with critical decisions during flood emergencies. BUILDING STRONG® If you have questions regarding USACE programs: Contact: ► Trena Bradshaw – District Outreach Coordinator • [email protected] • 615-736-7191 ► Phyllis Kohl – Floodplain Management Services Program • [email protected] • 615-736-5948 BUILDING STRONG® Questions? BUILDING STRONG®