Corps lakes providing water supply and water quality releases due to drought

Published Aug. 29, 2012

ROCK ISLAND, Ill. – The Rock Island District, U.S. Army Corps of Engineers, is currently operating its three Iowa reservoirs for drought conditions. With significantly decreased inflows, Saylorville Lake at Des Moines, Iowa; Lake Red Rock at Knoxville, Iowa; and Coralville Lake at Iowa City, Iowa; continue to release water to provide water supply and water quality for communities and utility needs downstream of the reservoirs.

Current flows at Saylorville Lake are 150 cubic feet per second (cfs) inflow, 210 cfs outflow; inflow and outflow at Lake Red Rock is 320 cfs; inflow at Coralville Lake is 110 cfs, outflow is 150 cfs. Minimum outflows will be maintained for as long as needed to ensure water supply and water quality below the reservoirs.

With outflows exceeding inflows into the reservoirs, pool levels will gradually lower. In the absence of significant rainfall pool levels are projected to drop ½ foot to 2 feet per month. The current pool level at Saylorville is 835.9 feet; at Lake Red Rock, 742.4 feet; and at Coralville Lake, 683.4 feet.

Boaters, jet skiers and other lake users should use caution in the upper portions of the lakes and along the shorelines as pool levels will be lower than normal. Decreased inflows and lower lake levels may also prevent fall pool raises to accommodate migrating bird species and provide fish and wildlife benefits.

Drought operations will continue until reservoir inflows exceed target downstream release rates and the reservoirs return to normal conservation pool levels. The conservation pool levels are: Saylorville Lake, 836 feet; Lake Red Rock, 742 feet; and Coralville Lake, 683 feet.

Release no. FY12-08-32