February 2008 USGS Maryland-Delaware-DC Water Conditions Summary
Compiled by Wendy S. McPherson, Hydrologist
Streams and wells responded to the above normal rainfall in February throughout most of the Maryland, Delaware, and the District of Columbia area, however, water levels in Central and Southern Maryland and the Delmarva Peninsula remain very low. Sixty percent of the streams are at normal levels with 20% above and 20% below normal. Regionwide, ground-water levels have shown improvement, but have not recovered fully. In February, 62% of the wells used by the U.S. Geological Survey (USGS) to monitor water conditions were below normal, while in January, 77% were below normal.
Precipitation
February 2008 rainfall was above normal at the National Weather Service stations in Maryland, Delaware, and the District of Columbia. However, the rainfall deficit for the past 365 days is more than 10 inches in Dorchester, Howard, Montgomery, Talbot, and Wicomico Counties in Maryland, and Sussex County in Delaware.
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
Streamflow at gages used by the USGS as climate indicators across the Maryland, Delaware, District of Columbia region was normal at 18 of 30 stations. Six sites were above normal and another 6 sites were below normal. The lowest streamflow levels are in southern Maryland and the Delmarva Peninsula.
Ground Water
Ground-water levels are recovering from their low levels, although 62% of the unconfined wells used by the USGS to assess response to climatic conditions were below normal. The areas with the lowest ground-water levels are the Delmarva Peninsula and Central and Southern Maryland.
The 5-year hydrograph for this deep, unconfined well in Baltimore County shows the water level (shown as a dark line) has dropped from a record high at the beginning of 2004 to below normal levels. Water levels in this well typically respond slowly to climatic conditions.
Chesapeake Bay Freshwater Flow
The estimated mean monthly flow to the Chesapeake Bay for February was 127,000 cfs (cubic feet per second) or about 123 percent of the long-term mean for February. Average February flow is 103,000 cfs.
Reservoirs
Water available from the Baltimore reservoir system (Loch Raven, Liberty, and Prettyboy) increased 11% to 78% of the available storage (59.6 billion gallons) at the end of February.
Water stored in the Triadelphia and Duckett Reservoirs, which serve Montgomery and Prince George's Counties, increased 10% to 70% of the normal capacity at the end of February.
| January 2008 | Percent available | Volume (billion gallons) | Source |
|---|---|---|---|
| Baltimore Reservoirs | Baltimore City | ||
| Loch Raven | 93% | 19.6 | Increased 15% since January 2008 |
| Liberty | 79% | 27.7 | Increased 7% since January 2008 |
| Prettyboy | 72% | 12.3 | Increased 11% since January 2008 |
| Total | 78% | 59.6 | Increased 11% since January 2008 |
| Patuxent Reservoirs | WSSC | ||
| Triadelphia | 64% | 3.59 | Decreased 8% since January 2008 |
| Duckett | 77% | 3.85 | Increased 30% since January 2008 |
| Total | 70% | 7.44 | Increased 10% since January 2008 |
More Information
- Maryland-Delaware-District of Columbia
- USGS Drought Watch
- USGS Water Summary
- Streamflow
- Ground Water
- Chesapeake Bay
- National
- USGS Streamflow and ground-water levels
- U.S. Drought Monitor from the National Drought Mitigation Center
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
