Lake Conroe was designed for water supply and not for flood control. As a result, a flood control release policy was not established for the reservoir. This study seeks to establish the effect of Lake Conroe releases on downstream flooding and to develop operational policies to release the excess stormwater from the reservoir. A computer model was programmed on a microcomputer (Apple IIe) to simulate the response of the Lake Conroe watershed to a storm event and to provide the operators at Lake Conroe with a viable method of on-line simulation. The model was calibrated with data from four historical events and verified against simulations from HEC-1, a flood hydrograph model. Recommended operational policies on four design storms were developed with the objective of minimizing peak releases from the dam. Guidelines for developing a release scheme for any design storm event were established based on the results of the HEC-1 analysis.