A critical issue facing DOTs is determining the extent and the severity of flooding events. Roadways and bridge flooding have significant economic impacts and are a major contributor to deaths during flood events. State department of transportation (DOTs) and other state and local agencies have implemented integrated flood warning and response systems. This is critical for staging personnel, inspecting bridges, and flood tracking through the state. Support for these efforts can come from internal products, flood inundation mapping using current and projected conditions, turnkey products on the market, the United States Geological Survey (USGS) gaging network and the National Weather Service flood forecast.
In addition to anticipating flood areas, states are tasked with alerting the public about affected areas and protecting them from these hazards. DOTs and other agencies must determine the flood’s extent and severity to effectively work with emergency management and inform the public about road closures and detour routes. There are multiple methods of warning the public about floods including warning lights tied to gages, sensors, personnel blocking off areas, warnings on official websites, and using USGS and National Weather Service products. Communication is key to the effective response before, during, and after flood events. Communication gaps within and between agencies have been identified following recent flood events such as those in North and South Carolina between 2015 and 2018.
The objective of this synthesis is to document the integrated flood prediction and response systems being used by state DOTs.
Information to be gathered includes, but is not be limited to:
· Flood prediction methods
· Risk thresholds that trigger action
· Methods and instruments used by DOTs to monitor flooding
· How DOTs determine the extent and severity of floods
· Available warning systems and methods
· Practices by DOTs for alerting the public, working with other agencies, and internal communication
· Successful systems as reported by DOTs
· Weaknesses in existing methods and what problems remain unsolved
Information will be collected through literature review, survey of DOTs, and follow-up interviews with selected agencies for the development of case examples that document successful practices. Case examples should cover a diverse range of geographic regions, flood causes and levels of government. Information gaps and suggestions for research to address those gaps will be identified.
· NCHRP 20-59 (53), A Framework for Enhanced Flood Event Decision Making for Transportation Resilience
· National Weather Service river forecasting models
· NOAA rainfall prediction models
· Young, C. B. Developing a Bridge Scour Warning System. University of Kansas. K-TRAN:KU-14-1. September, 2016.
· Morsy, M. M., G. L. O’Neil, J. L. Goodall, and G. Hassan. Computational Enhancements for the Virginia Department of Transportation Regional River Severe Storm (R2S2) Model. FHWA/VTRC 17-R18. May 2017.
· Murray-Tuite, P., G. J. Hannoun, A. Fuentes, K. Heaslip, V. Sridhar, P. Valayamkunnath, J. Goodall, and J. Sadler. Transportation Infrastructure Flooding: Sensing Water Levels and Clearing and Rerouting Traffic out of Danger. October, 2017.
· Collins, T., Y. Hong, T. Liu, J. Vogel, H. Yu, and L. Zhu. Decision Support System for Road Closures in Flash Flood Emergencies. OTCREOS11.1-41-F. June, 2013.
· Lissade, H. Flood Warning Alert System. Preliminary Investigation. December 2012.
· Ostheimer, C. J. Development of a Flood-Warning System and Flood-Inundation Mapping in Licking County, Ohio. SIR 2012-5137.
· Mantilla, R. and W. Krajewski. Real-Time Flood Forecasting and Monitoring System for Highway Overtopping in Iowa. TR-699. (Ongoing research).
· South Carolina Department of Natural Resources. South Carolina Flood Inundation Mapping. (Ongoing research).
Charles S. Hebson, Maine DOT
Rebecca Humphreys, Ohio DOT
Garrett Jackson, Washington State DOT
Menglin Jin, Department of Atmospheric and Oceanic Science, Univ. of Maryland, College Park
Thomas Knight, SCDOT
Stephen M. Sisson, Delaware DOT
Brinton Swift, Kiewit Infrastructure Engineering
Veronica Ghelardi, FHWA Resource Center Geotechnical & Hydraulic Team
William B. Anderson, Transportation Research Board
First meeting: September 19, 2019, Washington, DC
Second meeting: June 25, 2020