The Region's Reservoirs
One of the region’s most valuable natural assets is our reservoir system. The Loch Raven, Prettyboy and Liberty Reservoirs together provide high-quality water for approximately 1.8 million people in Baltimore City and the five surrounding counties. In addition, more than half the homes and several communities in the 467-square-mile reservoir watershed area depend on wells that draw from the watersheds’ groundwater.
The majority of the reservoir watershed area (290 square miles) is in Baltimore County. Another 165 square miles are in Carroll County. Very small portions are in Harford County and southern Pennsylvania. Only six percent of the watershed is owned by Baltimore City, which owns the three reservoirs and operates the central regional water system.
In addition to being the principal water supply source for the region, the reservoirs and their tributary streams offer extensive recreational opportunities and provide extensive and diverse habitats for fish and other wildlife. The reservoirs and their tributaries are aesthetic and recreational treasures.
In the 1970’s, pollution problems with algal blooms caused water treatment issues. The taste and odor for drinking-water customers became a problem. Too much phosphorus was causing eutrophication. These concerns led to a Reservoir Agreement in 1979, which was significantly strengthened in 1984, and then replaced by an expanded Reservoir Agreement signed in 2005.
Signatories of the Agreement include Baltimore and Carroll Counties, Baltimore City, Baltimore County Soil Conservation District, Carroll County Soil Conservation District, the Maryland Departments of Agriculture and the Environment, and the Baltimore Metropolitan Council. Other governments which participate include Anne Arundel, Harford and Howard Counties, all of them major users of reservoir water.
The 2005 Agreement has the fundamental goal of ensuring that the three reservoirs and their respective watersheds will continue to serve as sources of high-quality raw water for the Baltimore metropolitan water-supply system. Other goals address future loadings to the reservoirs of phosphorus, sediment, bacteria, sodium and chlorides; reducing the risk of contamination by hazardous materials; and promoting beneficial patterns of land use in the three watersheds.
The Action Strategy for the Region's Watersheds was created to further the goals of the 2005 Agreement.