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, water levels in the Aquia aquifer at Deale Athletic Field (AA Fe 92) have declined from about 24 in 2004 to about 34 feet below sea level in 2015. 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 three feet above sea level west of Annapolis (AA Dd 42) to about 27 feet below sea level in the Annapolis area (AA De 1 and AA Df 20 and 79). On the Broadneck Peninsula, the most recent water level recovered to just above 20 feet below sea level (AA Cf 99). Overall, water levels in the Magothy aquifer are relatively stable, with some areas still showing some modest decline.

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 69 feet above sea level in northern Anne Arundel County (AA Ad 108) to about 31 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 77 feet above sea level in northern Anne Arundel County (AA Bd 160) to about 54 feet below sea level at the Arnold well field (AA Cf 167). 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 (visible in AA Cg 24 as well). 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 110 feet below sea level in the Arnold well field (AA Cf 166). Beginning in about 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 100 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, water levels, having been stable since about 2003, declined approximately 25 feet since 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).