Corps Cuts Lake Red Rock Outflows to Reduce Mississippi River Flood Stages

Published April 19, 2011

ROCK ISLAND, ILL. -- Recent heavy rainfall in the Upper Mississippi River basin continues to raise river levels along the Mississippi River.  In an effort to reduce river stages and minimize impacts to Mississippi River communities downstream from the confluence of the Des Moines and Mississippi rivers, Lake Red Rock outflows are being reduced.  By tomorrow, Wednesday, April 20, Lake Red Rock outflows will be reduced from approximately 19,600 to 5,000 cubic feet per second1 and the Lake will be begin to store water.


Lake Red Rock is currently 0.88’ above its conservation pool level of 742’ National Geodetic Vertical Datum 29 and is expected to rise to approximately 754’ during the reduction in outflows.  Reduced outflows will continue for approximately seven days to offset Des Moines River flows into the Mississippi River.  This reduction will cause the Des Moines River to fall, and will assist in reducing Mississippi River levels.


Following this period, outflows will be gradually increased to approximately 30,000 cfs to maintain reservoir storage capacity.


In response to the Lake Red Rock reduction, Saylorville Lake’s outflow will be reduced to 6,000 cfs to balance storage between the reservoirs.  Once the outflow is reduced, Saylorville Lake's pool is expected to rise to 848' during the reduction of outflow.


Updated information about Lake Red Rock and Saylorville Lake levels, inflows and outflows; and river levels for the Des Moines and Mississippi rivers is available on the web by visiting the Corps’ website at


Web Links:


Reservoir Fact Sheets:

U.S. Army Corps of Engineers, Rock Island District:



– end –


1 NOTE:  Cubic feet per second (cfs).  The rate of flow past a given point, measured in cubic feet per second.  One cubic foot of water equals about 7 1/2 gallons.

Release no. 11-04-15