Maryland Department of Natural Resources

Anne Arundel County Observation-Well Network

The Anne Arundel 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.

Location of network observation wells

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 Anne Arundel County observation-well network, initiated in the late 1980's, is currently funded through a cooperative agreement between Maryland Geological Survey and Anne Arundel County Department of Public Works. The network consists of 42 wells located mainly in the central and northern part of the County. Aquifers monitored include the Patuxent (7 wells), Lower Patapsco (19 wells), Upper Patapsco (8 wells), Magothy (7 wells), and Aquia (1 well). Frequency of measurement ranges from 6 times a year to semiannual (spring and fall).



Current Water-Level Trends


hydrograph for observation well AA Fe 92 in the Aquia aquifer

Aquia aquifer


Since monitoring began in 2000, water levels in the Aquia aquifer at Deale Athletic Field (AA Fe 92) have declined from about 24 to 34 feet below sea level. While fluctuating by as much as 8 feet as a result of local pumpage, the overall water-level trend since about 2006 has been relatively flat.

hydrograph for observation well AA Df 79 in the Magothy aquifer

Magothy aquifer


The most recent water levels in the Magothy aquifer range from about four feet above sea level west of Annapolis (AA Dd 42) to about 25 feet below sea level on the Broadneck Peninsula (AA Cf 99) and in the Annapolis area (AA Df 20). Water levels in those areas declined after about 2006. Water levels in the City of Annapolis well field (AA De 1), while fluctuating in response to short-term pumping cycles, are relatively stable. Water levels in Southern Anne Arundel County (AA De 124 and AA Fe 93), after declining steadily since the late 1970’s in the case of AA De 124, show signs of stabilizing over the past several years.

hydrograph for observation well AA Cg 24 in the Upper Patapsco aquifer

Upper Patapsco aquifer


The most recent water levels in the Upper Patapsco aquifer range from about 75 feet above sea level in northern Anne Arundel County (AA Ad 108) to about 30 feet below sea level on the Broadneck Peninsula (AA Cf 134). Recent water-level trends in the Upper Patapsco aquifer are stable or recovering in the Glen Burnie area (AA Ad 108 and AA Bd 159), and declining on the Broadneck Peninsula (AA Cf 134, AA Cg 24, and AA Df 19), and south of Annapolis (AA De 128). Drawdown on the Broadneck Peninsula has increased since about 2006. In the Broad Creek and City of Annapolis well fields (AA De 95 and AA De 219, respectively), water levels, while fluctuating in response to short-term pumping cycles, are relatively stable.

hydrograph for observation well AA Cf 137 in the Lower Patapsco aquifer

Lower Patapsco aquifer


The most recent water levels in the Lower Patapsco aquifer range from about 75 feet above sea level in northern Anne Arundel County (AA Bd 160) to about 90 feet below sea level at the Arnold well field (AA Cf 137). Water-level trends in the Lower Patapsco aquifer are stable or recovering in the Glen Burnie area. In the Crofton Meadows well field, the water-level trend over the past several years has been relatively stable (AA Cc 89 and AA Cc 115) or declining (AA Cc 116 and AA Cc 137). The water-level trend at the Arnold well field (AA Cf 137) has been relatively stable between 1988 and about 2010; however, in the past several years drawdown has increased (AA Cf 137 and AA Cg 23). Water levels at the Broad Creek well field (AA De 206), while fluctuating as a result of short-term pumping cycles, appear relatively stable.

hydrograph for observation well AA Cf 166 in the Patuxent aquifer

Patuxent aquifer


The most recent water levels in the Patuxent aquifer range from about 32 feet above sea level south of Ft. Meade (AA Cb 1) to about 105 feet below sea level in the Arnold well field (AA Cf 166). Beginning in 2006, the water-level trend has been relatively stable in the Dorsey Road well field (AA Ad 90). In the Crofton Meadows well field (AA Cc 102 and 135), water levels, while fluctuating in response to short-term pumping cycles, are relatively stable. In the Arnold well field (AA Cf 166—remote test well), the water level declined approximately 95 feet since mid-2011 as a result of development of that aquifer at the Arnold well field. The increased withdrawals resulted in a decline of more than 40 ft in a monitoring well located about 5 miles to the east (AA Cg 22). In the Severndale well field (AA Ce 117), water levels, having been stable since about 2003, declined approximately 25 feet since August 2012. This decline is attributed to withdrawals from the Patuxent aquifer in the Arnold well field (approximately 5.5 miles to the southeast of Severndale).