Queen Anne's County Observation-Well Network
The Queen Anne's County water-level network is one of five observation-well networks maintained by MGS and funded through cooperative agreements with Anne Arundel, Calvert, Charles, Queen Anne’s, and St. Mary’s counties.
The primary objective of these networks is to monitor the effects of water-supply withdrawals on groundwater levels at both a local (well field) and regional scale. More specifically the water-level data are used to help assess (1) long-term sustainability of the water supply; (2) well interference (drawdown at each well in a multiple-well system added to drawdowns at the other wells); (3) potential for increased development of the aquifers; (4) potential for salt-water intrusion, where applicable; and (5) the role of ground-water extraction in land subsidence.
The Queen Anne's County observation-well network is currently funded through a cooperative agreement between Maryland Geological Survey and Queen Anne's County Department of Public Works. The network consists of 27 wells located mainly in the western (Kent Island) portion of the County. Aquifers monitored include the Surficial (Columbia) (2 wells), Aquia (17 wells), Magothy (1 well), Upper Patapsco (3 wells), Lower Patapsco (3 wells), and Patuxent (1 well). Frequency of measurement ranges from 12 times a year to semiannual (spring and fall).
Current Water Level Trends
While water levels in the Surficial aquifer fluctuate seasonally by about 5 ft, the long-term trend is flat. The water level in observation well QA Ec 1 shown on the hydrograph fluctuates up to the land surface. The trend in this well has remained the same since it was first measured in 1945.
The water levels in the Aquia aquifer observation wells continue to show flat long-term trends. There are 17 Aquia aquifer wells in the network in Queen Anne’s County, 14 of them are located on Kent Island. Observation well QA Ea 78 shown on the hydrograph was drilled at the Natural Police Academy in Matapeake to a depth of 135 ft. The Aquia aquifer observation wells range in depth from 120 ft in the northern part of Queen Anne’s County to 350 ft in Prospect Plantation in the southern part of the County.
One well (QA Ea 27) is completed in this aquifer. The water level has shown a steady decline of about 0.6 ft per year over the last several decades. Since 2015, water levels have leveled off.
Upper Patapsco aquifer
Water levels in the Upper Patapsco aquifer observation wells are affected by pumpage and continue to decline as shown on the hydrograph of observation well QA Ef 29. There are 4 Upper Patapsco aquifer wells in the network in Queen Anne’s County ranging in depth from 495 ft at Kingstown in the northern part of the county to 1,326 ft at Tuckahoe State Park, in the southern part of the County.
Lower Patapsco aquifer
As shown on the hydrograph of well QA Be 15, the water level in the Lower Patapsco aquifer is declining. There are 3 Lower Patapsco wells in the network in Queen Anne’s County ranging in depth from 1,170 ft at Kingstown to 1320 ft at Chester.
One well (QA Eb 110, near Chester on Kent Island) is completed in the Patuxent aquifer. The water level in this well had been declining steadily (~0.4 ft/year) between about 1988 and 2012. Beginning in 2012, the water level has been declining by about 3 ft/year, likely due to pumpage from the Arnold well field in Anne Arundel County, located about 12 miles west of QA Eb 110. QA Eb 110 is 2,485 ft deep.