January 2009 USGS Maryland-Delaware-DC Water Conditions Summary

Monthly mean streamflows for January were normal in 73% of the streams used by the U.S. Geological Survey (USGS) to monitor water conditions across Maryland, Delaware, and the District of Columbia. Streamflow for the remaining streams was below normal. Groundwater levels were normal in 62% of the wells used by the USGS to assess response to climatic conditions during January. The remaining 38% were below normal. Precipitation was below normal in Maryland, Delaware, and the District of Columbia.

Precipitation

January rainfall and snowfall were below normal at weather stations across Maryland, Delaware, and the District of Columbia, according to data from the National Weather Service. The Hagerstown weather station does not have enough record to calculate statistics.

January precipitation varied from above normal in Allegany County, Maryland (+0.2 inches) and New Castle County, Delaware (+0.1 inches) to below normal in Somerset County, Maryland (-1.9 inches) and Sussex County, Delaware (-1.2 inches). Rainfall for the last 365 days was in the normal range throughout Maryland, Delaware, and District of Columbia (data from MARFC).

Source: National Weather Service
MD and DC: http://www.weather.gov/climate/index.php?wfo=lwx
DE: http://www.erh.noaa.gov/phi/
Middle Atlantic River Forecast Center: http://www.erh.noaa.gov/marfc/Maps/precip.html

Streamflow

Monthly mean streamflow was normal in 22 of the 30 streams used to assess climatic conditions in Maryland, Delaware, and the District of Columbia. Streamflow levels in many of the streams, such as the Monocacy River, dropped from their high December level. Streamflow in the remaining 8 streams was below normal. Six of these streams were on the Delmarva Peninsula.

The monthly mean streamflow for the Monocacy River decreased from above normal in December to below normal in January. The 5-year hydrograph shows the monthly mean streamflow as a dark line and normal (between the 25th and 75th percentiles) as a white band.

Five-year hydrographs for these streams can be viewed at: http://md.water.usgs.gov/surfacewater/streamflow/

Groundwater

Groundwater levels were normal in 16 of the 26 wells used by the USGS to assess climatic conditions. The remaining 10 wells had below normal water levels. The below normal water levels were primarily in central and southern Maryland, and Delaware.

The 5-year hydrograph shows the water level as a dark line and normal (between the 25th and 75th percentiles) as a white band. The water level in the well in Baltimore County, Maryland continues to be below normal, although the water level follows the seasonal trend.

Five-year hydrographs for these wells can be viewed at: http://md.water.usgs.gov/groundwater/web_wells/current/water_table/counties/

Reservoirs

Water available from the Baltimore reservoir system (Loch Raven, Liberty, and Prettyboy) increased 1% to 92% of the available storage (69.84 billion gallons) at the end of January, 2009.

Water stored in the Triadelphia and Duckett Reservoirs, which serve Montgomery and Prince George's Counties, increased 3% to 58% of the normal capacity at the end of January, 2009. The level in Triadelphia is being kept low for gate maintenance.

More Information

Maryland-Delaware-District of Columbia

USGS Drought Watch

USGS Water Summary

Streamflow

Groundwater

Chesapeake Bay

National

USGS Streamflow and Groundwater levels

U.S. Drought Monitor from the National Drought Mitigation Center

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Contact

U.S. Department of the Interior
U.S. Geological Survey

Wendy S. McPherson (wsmcpher@usgs.gov)
Maryland-Delaware-D.C. Water Science Center
5522 Research Park Drive
Baltimore MD, 21228
Phone:443-498-5555
Fax:(443-498-5510