Boneyard Creek Channel Capacity Analysis
Flooding of the Boneyard Creek in the cities of Champaign and Urbana, Illinois has been a recurring problem since gradual urbanization of the area more than a century ago. Recently a new method has been developed to assess flooding problems along a channel system by hydraulically determining the capacities of the system and comparing them with the amount of water to be drained, which is determined hydrologically. In this report the determination of the capacities of the Urbana city portion of the Boneyard Creek for the 1997 channel conditions is presented. This capacity determination is achieved through the use of Yen and Gonzalez’s method of hydraulic performance graph (HPG). Furthermore, the locations of the bottlenecks that are most critical to flooding are identified and the improved capacities with these bottlenecks removed are investigated. Results revealed that the overall capacity of the Urbana portion of the Boneyard for stages between 700.0 ft and 701.5 ft at its confluence with the Saline Branch is controlled by the limited capacity of the segment of the creek between the upstream side of the Main Street Bridge and the downstream side of the Lincoln Avenue Bridge. Other major bottlenecks are the Huey Bridge and the closed-top structures at the Phillips Recreation Center. Removal of Huey’s Bridge will increase the system’s capacity by approximately 40 cfs. Removal of both the Huey and Phillips Recreation Center bottlenecks will increase the system’s overall capacity by about 100 cfs or 6%.