OHD - Dis_Svy Red River Flood 97 Executive Summary

EXECUTIVE SUMMARY

Flooding on the Red River of the North in 1997 established (twentieth century) records at most locations and was particularly devastating in the towns of Grand Forks, North Dakota, and East Grand Forks, Minnesota. With the exception of Grand Forks, which exceeded the previous (1979) record by over 5 feet, observed crests at most other forecast locations on the Red River of the North were about 2 feet above the previous records. Estimated damages for the complete event, including all United States portions of the Red River of the North, totaled about $4 billion, of which $3.6 billion occurred in the immediate vicinity of Grand Forks / East Grand Forks. No deaths directly attributable to the flooding resulted from this event. The National Oceanic and Atmospheric Administration (NOAA) typically conducts a post-event survey for events of this magnitude. The NOAA disaster survey team found instances of innovative and excellent performance and instances where NWS products and services could be improved.

NWS services beginning with early outlooks calling for record flooding and continuing through the flood event itself were generally informative and acceptable at all of the forecast points on the Red River of the North, with the exception of Grand Forks. Forecast errors at Grand Forks were due to the unprecedented complex interaction of hydrologic and hydraulic conditions. This report notes limitations to current flood forecasting techniques and capabilities, identifies areas for improving communications between the NWS and cooperating agencies, and provides recommendations for improving the way the NWS prepares and explains its flood forecasts.

The survey team recommended several steps be taken to improve the hydrologic forecast process through a series of important investments in NWS forecast procedures. The NWS needs to improve the methods used to estimate and convey the uncertain nature of its flood forecasts and outlooks. The most promising methods to address these issues have been prototyped in the Des Moines demonstration of the Advanced Hydrologic Prediction System, which should be extended to National coverage as resources allow.

The survey team found that cooperation among the USGS, the USACE, and the NWS was instrumental to the services the NWS provided. The survey team also supports the interagency technical review hosted by the North Central River Forecast Center (NCRFC) on July 28-30, 1997, in Chanhassen, Minnesota, as an ongoing step in the interagency review of technical methods used to forecast flooding in the Red River of the North.