Cooperative Water Supply Operations on the Potomac
Interstate Commission on the Potomac River Basin
Water Supply Management
ICPRB’s Section for Cooperative Water Supply Operations on the Potomac (CO-OP) was established in 1979 to serve as a cooperative technical center on water resources in the Potomac basin. The Section consists of ICPRB’s District of Columbia, Maryland, Virginia, West Virginia, and Federal Commissioners.
Learn more about the history of cooperative water supply on the Potomac.
Find minutes and upcoming dates on the CO-OP Meetings page.
A Cooperative System
The Washington, D.C., metropolitan area relies on the Potomac River to supply approximately three-quarters of the water it uses and benefits from a unique cooperative system of water supply management put in place over thirty years ago. The area’s three main water suppliers, Fairfax Water, Washington Suburban Sanitary Commission (WSSC Water), and the Washington Aqueduct (a division of the U.S. Army Corps of Engineers) share and jointly fund storage in upstream reservoirs. These suppliers also optimize the use of resources by coordinating their water supply operations during droughts.
ICPRB’s CO-OP Section played a key role in the development of this cooperative system and continues to provide technical and management support, including:
- Long-term planning to ensure that resources can meet future water demands;
- Drought monitoring and operations coordination to make efficient use of resources;
- Drought exercises conducted annually to practice communications and operational procedures; and
- Seasonal Water Supply Outlook & Status reports, published at the beginning of every month, April through October.
- The Potomac Basin precipitation map displays precipitation totals from the previous day, the previous three days, and the previous seven days.