911 Washington Ave, St. Louis, MO 63101

Various Culvert Replacements

M3 was part of the team for a project to replace three existing box culverts in St. Louis County: Villa Dorado Drive Culvert No. C-2-416 (11’h x 15’ w), Lackland Road Culvert No. C-2-116 (6’h x 12’w) and Lockwood Avenue Culvert No. C-4-224 (12’w x 8’h). M3 performed floodplain studies on the streams to ensure that the proposed structures do not cause an increase in the 100 year floodplain.  While not all the structures were located within FEMA defined floodplains, the hydraulic analyses and No-Rise verifications were required due to an MSD Special Requirement for any watercourse, not identified by FEMA, for which the 15-year, 20-minute design storm exceeds the capacity of a (60) inch diameter sewer. In addition to hydraulic design, M3...

Maline Creek Bank Stabilization

M3 Engineering Group was retained by The Great Rivers Greenway District to design two miles of greenway trail and three pedestrian bridges along Maline Creek. The project included design of a rain garden and stream biostabilization design at three separate locations to ensure that the new bridges would be supported by a competent streambank system. The streambank stabilization techniques included stacked stone toe protection, wrapped earth, willow staking, riffle pools and native plantings. The project is in St. Louis County’s Bella Fontaine Park located in the communities of Moline Acres and Bellefontaine Neighbors within the Maline Greenway. The park includes asphalt trails that lead to the pedestrian bridges and other features in...

Gravois Creek Stream Stabilization

M3 performed a Geomorphic Assessment on 8 miles of Gravois Creek to determine the streambank stability adjacent to a proposed sanitary storage tank and several large diameter sanitary sewers. he stream was suffering from bank erosion that threatened exposed sewers. The effort began with using M3’s GIS Streambank Assessment tool to forecast the future bank condition. M3 then performed geomorphic assessments in areas of proposed sewer construction and designed bank stabilization at several locations to protect the future sanitary facilities. The techniques included riffle-pool complexes, toe stabilization, bank plantings and stacked stone.  

Dougherty Lake Shoreline Protection

A lake owned by the St. Louis County Parks Department was suffering from shoreline erosion that was threatening the backyards of several residents adjacent to the lake. The residents reached out to the Parks Department, who then hired M3 to develop a solution. M3 found that, since the 1980’s, approximately 25 feet of bank had eroded away along 650 feet of shoreline. It was determined that the primary cause of erosion was wave action under windy conditions. The erosion was further aggravated due to the unstable soil type that was used to construct the lake. M3 proposed using heavy riprap on filter fabric to stabilize the banks. Due to the steep bank condition under the water surface, a special technique was utilized that involved dumping...