The national program of flood forecasting carried out by the National Weather Service and its river forecast centers is of significant value to a wide range of interests, but is critically important because it saves lives and dollars lost to flood damage. Improvements throughout the nation are necessary and are being achieved through the Advanced Hydrological Prediction Services (AHPS) programs of the Service. A network of precipitation (rain) gages, new radar systems, and stream gages deployed throughout the United States allow the experts in the forecasts centers to know how much rain has fallen, over what time period it fell, the continuing rate of rainfall and what stream conditions exist. Sophisticated models to allow the forecasters to issue alerts where and when needed. An example is the specialized forecasting tool in the Susquehanna River Basin that allows forecasts for that region to be issued promptly, thus giving the forecasters at the Mid-Atlantic River Forecast Center in State College, Pennsylvania information and decision tools to enhance the timing of flood warnings for the Susquehanna while increasing the time available to focus attention on other basins for which they are responsible, including the Potomac.
Increased skills and knowledge available at the various National Weather Service offices allows users such as the Interstate Commission on the Potomac River Basin to obtain support for needs in such areas as more reliable watershed runoff models to answer questions about drought and floods. This then allows information to be provided in a timely manner to operators of water supply systems who provide water to the Metropolitan Washington, DC region. These operators function in a scenario that demands providing a reliable, safe, and secure drinking water with little environmental consequences caused by the construction of storage reservoirs or allowing interbasin water transfers.