June 2008 USGS Maryland-Delaware-DC Water Conditions Summary
Compiled by Wendy S. McPherson, Hydrologist
Streamflows were normal at 87% of the streams monitored by the U.S. Geological Survey (USGS) in Maryland, Delaware, and the District of Columbia in June 2008. The remaining 13% were above normal. Nearly half (48%) of the wells had normal water levels in June, but 43% were still below normal. Only two wells in Washington County had water levels above normal.
Precipitation
Rainfall in June 2008 was above normal in Baltimore and Washington D.C., and below normal at the Wilmington and Georgetown weather stations according to the National Weather Service. The Eastern shore received from 1-3 inches above normal in June, while the northern counties of Maryland, such as Harford County, were more than an inch below normal.
The driest regions in June were Northern Maryland along the Pennsylvania border and into Northern Delaware. The wettest region was Southern Maryland, the Eastern Shore, and the Southern part of the Delmarva Peninsula. For the past 365 days, all counties in Maryland and Delaware are within the normal range or above. The largest deficit for the past 365 days is in Sussex County, Delaware, with 8.3 inches. In contrast, Garrett County, Maryland has a surplus of 8.3 inches.
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 levels were normal in 26 of the 30 streams used by the USGS as climate indicators across the Maryland, Delaware, and the District of Columbia region in June 2008. The 4 streams with above normal monthly mean streamflows were: Piscataway Creek and St. Clements Creek in Southern Maryland, and the Savage River and Youghiogheny River in Western Maryland.
The five year hydrograph for Nassawango Creek shows the monthly mean streamflow level (dark line) returned to normal in June. Worcester County received over 10 inches of rain in the last two months. The abundant rainfall in May brought the water level to above normal levels, and the more normal rainfall in June allowed the streamflow to return to normal. Streamflow had been below normal and sometimes record-setting low since April 2007.
Five-year hydrographs for these streams can be viewed at: http://md.water.usgs.gov/surfacewater/streamflow/
Groundwater
Groundwater levels in the unconfined wells used by the USGS to measure response to climatic conditions in Maryland and Delaware came down from the high levels in May. Nearly half (48%) of the wells were at normal water levels. Water levels were below normal in 43% of the wells, including Baltimore, Carroll, Frederick, Howard, and Wicomico Counties in Maryland. Water levels were also below normal in Delaware and the southern Delmarva Peninsula. Two wells in Washington County were above normal.
The 5-year hydrograph shows the water level as a dark line and normal (between the 25th and 75th percentiles) as a white band. Water levels for well CL Ad 47 in Carroll County dropped from above normal in May to below normal in June. Water levels typically drop at this time of year at this well, but the drop was quicker than normal.
Five-year hydrographs for these wells can be viewed at: http://md.water.usgs.gov/groundwater/web_wells/current/water_table/counties/
Chesapeake Bay Freshwater Flow
The estimated mean monthly flow to the Chesapeake Bay for June was 36,800 cfs (cubic feet per second) or about 56% percent of the long-term mean for June. Average June flow is 65,500 cfs.
Reservoirs
Water available from the Baltimore reservoir system (Loch Raven, Liberty, and Prettyboy) increased to 100% of the available storage (75.53 billion gallons) at the end of May.
Water stored in the Triadelphia and Duckett Reservoirs, which serve Montgomery and Prince George's Counties, increased to 100% of the normal capacity at the end of May.
| June 2008 | Percent available | Volume (billion gallons) | Source |
|---|---|---|---|
| Baltimore Reservoirs | Baltimore City | ||
| Loch Raven | 96% | ||
| Liberty | 100% | ||
| Prettyboy | 99% | ||
| Total | 97% | ||
| Patuxent Reservoirs | Washington Suburban Sanitary Commission (WSSC) | ||
| Triadelphia | 105% | ||
| Duckett | 91% | ||
| Total | 98% | ||
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
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
