Streamflow to Chesapeake Bay in 2000 Reflects Dry Autumn

In 2000, the average streamflow into the Chesapeake Bay was 42.2 bgd (billion gallons per day), which is 16 percent below the long-term average, according to hydrologists at the U.S. Geological Survey (USGS) in Baltimore, Maryland. The National Weather Service reports the yearly rainfall was above normal at BWI Airport (103 percent) and Wilmington (108 percent), but from October through December, rainfall at BWI was 5.58 inches less than normal. This unusually dry autumn resulted in the lower yearly average streamflow into the Chesapeake Bay (see graphs at http://md.water.usgs.gov/monthly/bay.html).

Although rainfall was below average in December, with only 2.31 inches at BWI in December, which is about 68 percent of the normal monthly rainfall, streamflow across Maryland and Delaware ranged from 48 percent below normal at the Potomac River near Washington, D.C., to 45 percent above normal for the Eastern Shore and Delaware. The Baltimore reservoir system is currently at 97 percent of capacity, and ground-water levels increased and are in the normal range for Maryland and Delaware. Monthly updates of ground-water conditions for 32 key observation wells that are representative of all counties of Maryland and Delaware can be found at http://md.water.usgs.gov/groundwater/.

As the Nation's largest water, earth and biological science, and civilian mapping agency, the USGS works in cooperation with more than 2,000 organizations across the country to provide reliable, impartial scientific information to resource managers, planners, and other customers. This information is gathered in every state by USGS scientists to minimize the loss of life and property from natural disasters, contribute to the sound conservation and the economic and physical development of the nation's natural resources, and enhance the quality of life by monitoring water, biological, energy, and mineral resources.

Posted: 2-1-2001