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Water Science for Maryland, Delaware and the District of Columbia

February 2018 Reservoir Levels

Baltimore Reservoirs

Baltimore City’s Department of Public Works provides finished drinking water from three reservoirs (Loch Raven, Liberty, and Prettyboy) to 1.8 million people daily in Baltimore City and parts of Baltimore, Anne Arundel, and Howard Counties in Maryland. Carroll and Harford Counties in Maryland also receive raw water from the Baltimore reservoirs. At the end of February 2018, available reservoir storage in the Baltimore Reservoirs was 69.87 billion gallons, or 92 percent, of available storage capacity (total or full storage is 75.85 billion gallons of water).

The Prettyboy Reservoir helps provide water for nearly 2 million residents in Baltimore City and parts of five neighboring Maryland counties.

Patuxent Reservoirs

The Triadelphia and Duckett Reservoirs serve 1.8 million residents in parts of Charles, Howard, Montgomery, and Prince George’s Counties in suburban Maryland around the District of Columbia, and are managed by the Washington Suburban Sanitary Commission (WSSC).

The stored water quantity for the Triadelphia and Duckett Reservoirs at the end of February 2018 was 4.71 billion gallons, which is about 45 percent of normal storage capacity for the two Patuxent reservoirs. The storage capacity numbers were updated in June 2017 by the WSSC.

The Duckett Reservoir is a Patuxent River Reservoir maintained by the Washington Suburban Sanitary Commission (WSSC).

Normal storage refers to the volume that is useable for water supply. The full capacity of the two Patuxent reservoirs is 11.93 billion gallons, which is higher than normal storage (10.57 billion gallons); therefore, full capacity values can exceed 100 percent of normal storage.

Note: The Triadelphia Reservoir storage level is low because of an ongoing project and will be kept low until 2019 or until the project is complete.


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