By John Daylor, P.E. (Tulsa District, Corps of Engineers)

Abstract: Keystone Dam and Reservoir is one of numerous impoundments on the Arkansas River system that is operated to meet multipurpose operational objectives. Current operation, in part, includes delaying the lower 30% of flood storage evacuation for some reservoirs to provide post-flood scour and dredging in the navigation system. Recent evaluation of Keystone Dam by the Corps of Engineers dam safety team resulted in safety concerns. As a result, a request was made for early screening and evaluation of alternative operation that involves evacuating Keystone Reservoir flood storage without delaying the lower 30%. A target flow guide curve for the lower Arkansas River is used for operation that is based on system percent flood storage and “fullness” of the reservoirs. Using the Corps of Engineers SWD flood control methods in RiverWare a period of record rule simulation analysis is performed to evaluate proposed changes of Keystone Reservoir operation. Results are compared to existing conditions run for evaluation. Analysis includes system effects as well as Keystone Reservoir. RiverWare statistical applications are also included.