Record Breaking High Water Levels in Maryland and Delaware

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

Contact:
Wendy McPherson (wsmcpher@usgs.gov)
Maryland-Delaware-D.C. Water Science Center
5522 Research Park Drive
Baltimore, MD 21228
Phone:(443)498-5500
FAX: (443)498-5510

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Updated: July 3, 2003

Two months of above normal rainfall have filled our rivers and raised the water table to record monthly high levels in Maryland and Delaware, according to hydrologists at the U.S. Geological Survey (USGS) in Baltimore. The May-June 2003 period was the fourth wettest on record and June was the eleventh coolest on record, according to the National Weather Service. Where does all of this rain go? Rainfall either soaks into the ground, saturating the soil and recharging the aquifers, or if the ground is saturated, the excess water runs off into streams, resulting in high streamflow levels.

June 2003 had the second highest total streamflow into the Chesapeake Bay since record-keeping began in 1937 (66 years). The only higher monthly streamflow was in June of 1972 when Hurricane Agnes engulfed the region. Five rivers set new high monthly mean streamflow levels for June, including the Nanticoke River in Delaware, which had the highest June flow in 55 years. Six wells reached their highest June groundwater level in 40 years. The sites that are not breaking records are at near record high levels.

The maps below show how the water resource situation has changed in Maryland and Delaware since last year when the region was experiencing the worst hydrologic drought on record.

For news release and images, visit:
http://md.water.usgs.gov/publications/press_release/current

In June 2003, all wells and streamflow stations used to monitor climatic conditions in the bi-state region were at above normal levels, and six of the wells were at their highest level in 40 years (shown as star symbols on map). In June 2002, most of the wells and streamflow stations were at below normal levels and six wells reached their lowest levels in more than 40 years. The USGS’s long-term data show that this number of sites has never before shown such an extreme change in water levels during a short period of time.

In several wells used by the USGS to monitor climatic conditions, record high groundwater levels were set in wells in Anne Arundel, Harford, and Washington Counties in Maryland and Kent and New Castle Counties in Delaware in June 2003. Groundwater levels are expected to drop during the growing season because of increased demand, but the abundant rainfall has raised groundwater levels, recharged the aquifers, and saturated the soil, making it difficult for farmers to work their fields. For 5-year hydrographs of groundwater levels, visit: http://md.water.usgs.gov/groundwater/.

The 5-year hydrograph for a well HA Bd 31 in Harford County, Maryland shows how recharge has occurred and the water level has recovered from record low levels last summer to normal levels in the fall and winter and continued to rise to above normal levels in the spring and summer. The water level has risen nearly 20 feet in less than a year.

Streamflow levels were above normal across Maryland and Delaware and the Nanticoke River in Delaware set a record high at the end of June. Record high monthly mean streamflow levels were set on the Choptank River, Savage River, and Youghiogheny River in Maryland, and Brandywine Creek and Nanticoke River in Delaware.

In the 5-year hydrograph for Brandywine Creek, the average streamflow levels (shown as a white band) fluctuate over the year based on the weather and growing season, yet typically decrease during the summer when there is an increased demand on water resources. Streamflow was at record low levels during the summer of 2002 and has risen during the last year to the largest June flow since record-keeping began in 1946.

The average monthly streamflow at the Potomac River near Washington, D.C. was 27.1 bgd (billion gallons per day), or 353 percent above normal (see graphs at http://md.water.usgs.gov/monthly/poto.html). This is the highest June streamflow since 1972 when Hurricane Agnes engulfed the region. With groundwater and streamflow levels already high, there is the potential for localized flooding (for information on flooding, see http://md.water.usgs.gov/faq/index.html#hydrologyoffloods).

The results of all the rain is that reservoir storage levels in both the Baltimore reservoir system and the Triadelphia and Duckett Reservoirs on the Patuxent River were at full capacity at the end of June. Reservoir data graphs can be viewed at: http://md.water.usgs.gov/.

Streamflow and groundwater levels are used to gauge water conditions and may be used to predict the potential for flooding and drought conditions. These USGS data have been provided to State and local water resource managers and are critical for making appropriate decisions on water restrictions. For more information on streamflow and groundwater levels in Maryland and Delaware, see Water Watch at: Water Watch.

Total flow into the Chesapeake Bay during June averaged 123 bgd (billion gallons per day), which is 197 percent above average and is the second highest flow since record-keeping began in 1937 (see http://md.water.usgs.gov/monthly/bay.html). There were several months with below normal total flow into the Bay during the drought years of 2001 and 2002. In 2003, the total flow has been above average each month. The possible consequences of increased streamflow into the Bay include degraded water-quality conditions in the spring and summer as larger amounts of nutrients and sediment are carried into the Bay. More information about water quality and the Chesapeake Bay can be found at: http://md.water.usgs.gov/monthly/bay.html.

Streamflow and groundwater levels are used to gauge water conditions and can be used to predict the potential for flooding and drought conditions. These USGS data have been provided to State and local water resource managers and are critical for making appropriate decisions on water regulation. For more information on streamflow and groundwater levels in Maryland and Delaware, see Water Watch at: Water Watch.

The real-time streamflow stations used in this analysis are operated in cooperation with the Maryland and Delaware Geological Surveys, the Maryland State Highway Administration, the U.S. Army Corps of Engineers, the Maryland Department of Natural Resources, the Maryland Department of the Environment, Baltimore County, and other agencies. The observation wells used in this analysis are operated in cooperation with the Maryland and Delaware Geological Surveys. The USGS publishes data for 137 streamflow stations and 379 observation wells across Maryland and Delaware.

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

The USGS, a bureau within the Department of the Interior, is the Nation's largest water, earth and biological science, and civilian mapping agency providing 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.

** * USGS * * *

In-depth information about USGS programs may be found on the USGS home page at http://www.usgs.gov and http://chesapeake.usgs.gov/ for Chesapeake Bay activities.

Archived News Releases 2000-Present

2006

• 01-06-2006 Water Resources Plentiful at End of December 2005; Chesapeake Bay Flow Normal in 2005

2005

• 07-06-2005 Water Levels Fall as Summer Arrives
• 04-06-2005 March 2005 Water Levels Near Normal
• 03-04-2005 Flow Below Normal in Potomac River and Chesapeake Bay
• 02-07-2005 January 2005 Water Levels Normal to Above Normal
• 01-07-2005 2004 Ends with Normal to Above Normal Water Levels

2004

• 12-04-2004 Water Levels Remain Generally Above Normal
• 11-04-2004 Dry October Causes Water Levels to Drop
• 10-06-2004 Highest September Flow to the Chesapeake Bay Since 1937
• 09-03-2004 August Hurricanes Raise Water Levels in Southern Maryland
• 08-06-2004 Localized Flooding in Northeastern Maryland and Delaware in July
• 07-07-2004 Water Levels Normal to Above Normal in June
• 06-04-2004 Streams Return to Normal Levels in Maryland and Delaware during May 2004
• 05-06-2004 Streams Rise to Above Normal Levels in Maryland
• 04-07-2004 Streamflow and Groundwater Levels Fell in March 2004
• 03-04-2004 Streamflow and Groundwater Levels Normal to Above Normal in February 2004
• 02-04-2004 Cold, Dry January Leads to Drop in Water Levels
• 01-06-2004 Wettest Year Leads to Record-High Water Levels Including Third Highest Flow to Chesapeake Bay in December and 2003

2003

• 12-04-2003 More Record-High Water Levels in November 2003
• 11-04-2003 Record High Groundwater Levels in October 2003
• 10-03-2003 Flow to Chesapeake Bay in Water Year 2003 Second Highest Since 1937
• 09-05-2003 Third Consecutive Month of High Flow into the Chesapeake Bay
• 08-06-2003 Flow into Chesapeake Bay near Record High Levels
• 07-07-2003 Record Breaking High Water Levels in Maryland and Delaware
• 06-06-2003 Streamflow and Groundwater Levels High in May
• 05-07-2003 April Water Levels Normal
• 04-05-2003 Water Levels High in March - Water Restrictions Lifted
• 03-05-2003 Exceptionally Wet February Leads to High Water Levels
• 02-06-2003 Maryland and Delaware Streamflow and Groundwater Levels Remain Normal in January 2003
• 01-07-2003 2002: A Record-Setting Year for Low Groundwater Levels - Water Levels Recover to Normal in December 2002

2002

• 12-01-2002 Hydrologic Drought Wanes as Water Levels Rise
• 11-01-2002 Water Levels Rise Across Maryland and Delaware, But Drought Persists in Some Areas
• 10-03-2002 Water Levels Remain at Record-Setting Lows
• 09-05-2002 Groundwater in Parts of Maryland Reaches Lowest Levels Since 1962, Despite Late August Rains
• 08-06-2002 Drought Conditions Lead to 10 Record Low Monthly Groundwater Levels in July
• 07-03-2002 Record Low Water Levels Show the Effects of Long-Term Hydrologic Drought
• 06-04-2002 Groundwater Levels Reflect Long-Term Effects of Drought
• 05-02-2002 April Showers Not Enough to Raise Groundwater Levels
• 04-05-2002 The Drought in Full Bloom: Low Water Levels Result in Water Restrictions

2001

• 12-03-2001 Record Low Water Levels Set in November
• 11-02-2001 Dry October Leads to Low Water Levels
• 10-05-2001 Water Levels Low in Northern Maryland
• 09-07-2001 Water Levels Stable in August
• 08-06-2001 High and Low Water Levels in July
• 07-06-2001 Water Levels Continued to Improve in June
• 06-06-2001 Needed Rain Helps Avert a Drought in May
• 05-08-2001 Water Levels Still Normal in April, but More Rain is Needed
• 04-05-2001 Spring Rains Help Water Levels
• 03-06-2001 Water Levels Improve, But Are Still Below Normal
• 02-06-2001 Streamflow Still Low in Maryland in January
• 01-05-2001 Streamflow to Chesapeake Bay in 2000 Reflects Dry Autumn

2000

• 12-05-2000 Streamflow in Maryland Beginning to Show the Effects of Lack of Rain
• 11-07-2000 Despite Lack of Rain October Water Conditions near Normal
• 10-06-2000 September Water Conditions Above Normal in Maryland, Delaware, and D.C.
• 09-08-2000 August Water Conditions Above Normal in Maryland, Delaware, and D.C.
• 08-07-2000 July Water Conditions Continue Normal in Maryland, Delaware, and D.C.
• 07-07-2000 June Water Conditions Normal in Maryland, Delaware, and D.C.
• 06-06-2000 Water conditions begin to decline in Maryland, Delaware, and D.C.
• 05-05-2000 Water Conditions Continue to Improve in Maryland, Delaware, and D.C.
• 04-07-2000 Water Conditions Continue to Improve in Maryland, Delaware, and D.C.
• 03-07-2000 Water Conditions Improving in Maryland, Delaware, and D.C.
• 02-08-2000 January Streamflow and Ground Water Levels Still Low
• 01-06-2000 1999 Flow Into Chesapeake Bay Lowest Since 1960s Drought