Anne Arundel County Observation-Well Network
Project Details
- Latest Data Report:Hydrographs and tables showing ground-water level and pumpage records for selected observation wells in Anne Arundel County, Maryland and hydrograph showing surface-water flow in Sawmill Creek, 2025 report [2 MB])
- Project Data:Explore an interactive map with links to current water levels
Continuous water-level data - Project Staff:Tyler Van NessIsabel Glasman
The Anne Arundel County water-level network is one of three county observation-well networks maintained by MGS and funded through county cooperative agreements. Other counties include Charles and Queen Anne’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 Anne Arundel County observation-well network, initiated in 1986, 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 (9 wells), Magothy (6 wells), and Aquia (1 well). Frequency of measurement is 6 times a year, semiannual (spring and fall), or continuous.
Current Water-Level Trends
Aquia aquifer
Water levels were measured in one well in this aquifer. The water level at the Deale Athletic Field (AA Fe 92) was 34.63 ft below sea level. Over the past year, the water level decreased by 1.88 ft. Overall trends since 2005 are relatively flat due to the reduction of regional withdrawals from the Aquia aquifer in St. Mary’s County as pumpage was shifted to the deeper Upper Patapsco aquifer to avoid elevated arsenic concentrations in the Aquia aquifer.
Magothy aquifer
Water levels were measured in six wells in this aquifer. Current levels range from 2.03 ft above sea level at Route 50 and Howard Grove Road (AA Dd 42) to 22.91 ft below sea level at the Traffic Engineering Building, Broad Neck (AA Cf 99). Overall trends since 2015 have continued to be flat in response to withdrawals, with the exception of AA Cf 99 which shows a response to local pumping conditions.
Upper Patapsco aquifer
Water levels were measured in eight wells in this aquifer. Current levels range from 70.50 ft above sea level at Aviation Blvd., Glen Burnie (AA Ad 108) to 32.39 ft below sea level at the Broad Creek Water-Treatment Plant (AA De 95). Recent pumpage in Broad Creek ranged from 0 gallons per day (Jul through Sep 2024 and Feb 2025) to 1.22 million gallons per day (Dec 2024). Within the past five years, water levels in the Upper Patapsco aquifer exhibit a relatively flat trend while Aviation Blvd (AA Ad 108) and Rippling Woods Elementary School (AA Bd 159) have a generally decreasing trend. AA De 95 has fluctuated as much as 32.81 ft. over the past year.
Lower Patapsco aquifer
Water levels were measured in 19 wells in this aquifer. Current levels range from 75.31 ft above sea level at Queenstown Park, near Glen Burnie (AA Bd 160) to 79.80 ft below sea level at the Crofton Meadows Water-Treatment Plant (AA Cc 115). Recent pumpage in Crofton ranged from 4.99 million gallons per day (Mar 2025) to 8.30 million gallons per day (Jun 2025). In Arnold, recent pumpage ranged from 3.92 million gallons per day (Jun 2025) to 7.31 million gallons per day (Jul 2024). Water levels in this aquifer fluctuated in response to water use, especially at the Crofton Meadows (AA Cc 115 and AA Cc 137) and Arnold (AA Cf 137), where water levels fluctuated 32.96 ft, 48.08 ft, and 41.53 ft, respectively, over the past year. Despite fluctuations in response to pumpage, overall water level trends are generally flat or increasing in all wells except at Aviation Blvd., Glen Burnie (AA Ad 102), the King Heights Water-Treatment Plant (AA Cc 82), and the City of Annapolis (AA De 232). While AA Ad 102 is currently showing a decreasing trend over the past five years, there is generally flat trend in the water level since 2007.
Patuxent aquifer
Water levels were measured in seven wells in this aquifer. Current levels range from 13.20 ft above sea level at the Patuxent Wildlife Refuge Center (AA Cb 1) to 133.77 ft below sea level at the Arnold Water-Treatment Plant (remote site) (AA Cf 166). Recent pumpage in Crofton ranged from 4.85 million gallons per day (May 2025) to 7.29 million gallons per day (Jul 2024). Recent pumpage in Arnold ranged from 3.23 million gallons per day (Nov 2024) to 4.08 million gallons per day (Jul 2024). Over the past year, the water level in all of the wells remained declining in response to increased withdrawals, except for Aviation Blvd., Glen Burnie (AA Ad 90) which, while decreasing over the entire period of data collection, shows a generally flat trend within the past five years. Water levels in this aquifer fluctuated in response to water use, especially at Crofton Meadows (AA Cc 135) and Arnold (AA Cf 166) where levels fluctuated as much as 45.75 ft and 24.24 ft, respectively, over the past year.