Authorized by the Flood Control Act of 1958, the Michael J. Kirwan Dam and Reservoir is one of 16 flood control projects in the Pittsburgh District. The project provides flood protection for the Mahoning River Valley and the Beaver and upper Ohio River.
Since its completion in 1966, the Kirwan Reservoir has prevented flood damages estimated to be in excess of $755 million. Kirwan has the capability to store the equivalent run-off of 18.35 inches of precipitation from its 80.5 square mile drainage area. When compared, the $20 million cost of construction is far outweighed by the project’s flood prevention benefits.
Kirwan also stores water for release downstream during dry periods. This has the effect of improving both the quality and quantity of flow in the Mahoning River for domestic and industrial use, recreation, aesthetics and aquatic life.