Cole Creek at Droste Road, Stream Restoration

Client: City of St. Charles, MO
Owner: City of St. Charles, MO
Year: 2014

M3 Engineering was selected to restore 1,700 feet of degrading stream in St. Charles, MO. The stream was down cutting and the banks were collapsing in several locations, threatening several properties. M3 modeled the stream using HEC-RAS to determine the hydraulic characteristics. M3 also performed a geomorphic assessment to determine the root cause of the degradation and then decided which restoration techniques were suitable for repairing the stream.​ Increased imperviousness within the Cole Creek watershed has led to increased peak flows and total runoff volumes. The stream was suffering from ongoing degradation in certain sections, including the 1,700 foot section between Southwick and Droste. There were 36 properties that was affected by the degradation, which included down cutting, bank sloughing, toe scour and exposed piping. M3 Engineering addressed the situation by first performing a geomorphic assessment of the stream to determine the root causes of the degradation. An environmental scientist and a hydraulic engineer walked the length of the stream to assess the existing stream conditions and to inventory the current vegetation. A HEC-RAS model was prepared to define the existing and proposed hydraulic conditions. The improvements were not allowed to cause a rise in the 100 year water surface elevation. Proposed biostabilization techniques included wrapped earth, rock toe, riffle-pool complex, willow staking and root wads. The solutions were designed to restore the stream with natural, sustainable, methods that create wildlife habitat.

Projects - Stream Restoration