Wise and Mabel Storm and Combined Separation

Wise and Mabel Storm and Combined Separation

Client: Burns & McDonnell Owner: Metropolitan St. Louis Sewer District​ Year Completed:​​​​ 2011

M3 Engineering was a subconsultant to Burns & McDonnell for an MSD project that helped reduce flooding and backups in Richmond Heights, MO by separating storm drainage from combined sewers and constructing a new storm sewer that will discharge into Claytonia Creek. M3 Engineering modeled the existing and proposed enclosed systems using XP-SWMM. The existing combined sewer overflows to Claytonia Creek during wet weather. The proposed system consists of approximately 9,225 feet of 12-inch to 72-inch diameter storm sewer and approximately 1,080 feet of 12-inch diameter combined sewer and appurtenances. The estimated construction cost is approximately $4.6 million. Existing downspouts, driveway drains and area drains that currently drain to the combined sewers will be directed to the new storm system that will discharge to Claytonia Creek. Claytonia Creek is a FEMA regulated stream, so improvements cannot cause a rise in the 100 year water surface. Because of this, M3 Engineering also modeled the existing and proposed stream conditions using HEC-RAS to determine the effects of the change in flow.

Projects - Stormwater