SEATTLE -- Sophisticated technology to map flood-prone areas and forecast flood conditions in the Puget Sound region hasn't been deployed yet, and money is part of the delay.
The National Weather Service has deployed its Advanced Hydrologic Prediction Service across the country, but it’s in a relatively small number of cities, especially in the Mississippi and Ohio River valleys. The closest area covered by the service is Boise, Idaho.
(A page on the NWS website shows data from the system: Try moving your mouse on the left side of the screen to see how higher flow levels on the Boise River cause greater flooding and where. Users can also click on specific areas on the map to see how much water is expected depending on flood conditions.)
To create AHDP maps, the Weather Service needs help from the U.S. Army Corps of Engineers or state and local emergency management agencies to cover the costs of airplanes equipped with LIDAR (LIght Distance And Ranging) technology -- sensors that use laser rangefinders to produce accurate topographic surveys that show how high particular geographic points are within one foot. NWS already collects data on river and stream levels, so pairing that information with the LIDAR maps can provide more specific flood forecasts and help emergency managers pinpoint which areas are likely to be flooded and at what depth.
Brent Bower, a senior hydrologist with the National Weather Service in Seattle, said he’s hoping to see the program rolled out in Western Washington within two years. As it is, Boise’s map is only about six months old.