Overview
The City of St. Peters contracted Horner & Shifrin, Inc. (H&S) to provide professional engineering services for the evaluation and recommendation of a master stormwater drainage ditch system for the area north of Interstate 70 and bound by the Old Town Levee, with Spencer Creek to the east and Dardenne Creek to the west. The City requested the study also contain an evaluation of the existing Regional Detention Basin located on City of St. Peters’ property to the north of Recycle City, and the evaluation and recommendation of improvements to Interior Ditch B.
The Improvements to Interior Ditch B included clearing of brush along the entire 2,000 LF of creekbank, removal of temporary culverts that constricted the design flow, and widening of the ditch at the downstream end where it entered the regional detention basin.
Improvements to the Regional Detention Basin were determined to not be necessary through the XP-SWMM modeling process. The existing pumps were adequate to keep the detention basin from flooding nearby properties in the design storm fully-built out condition. Multiple scenarios and cost estimates were provided to the City for consideration.
Finally, the Stormwater Master Plan was provided to the City to make incremental improvements in the stormwater conveyance of the drainage area. Multiple ditches and culverts were recommended for construction or enlargement to convey the 100 year storm in the event the drainage area became completely built out. The deliverable to the City included a report, Autocad drawings of the survey collected in the field, and GIS files indicating replacement culverts, new culverts, enlarged ditches, and proposed easements.
