The City of Waukesha planned to implement storm sewer improvements in Area 7 (North High School vicinity) as proposed in their 2014 Stormwater Management Plan. The 2D XPSTORM model previously prepared for Area 7 was terminated just west of N. University Drive, at the inlet to a stormwater pond on privately owned land. raSmith staff took the existing model and updated it to provide the City with the effects of the planned storm sewer improvements as well as alternatives for flows and flood levels in the receiving stormwater pond and downstream along the waterway to the large wetland west of Les Paul Parkway (County TT).
raSmith staff evaluated alternatives using XPSTORM that included four culvert replacements and floodplain bench grading along an existing drainage ditch. The new conveyance system alleviated flooding concerns upstream of the project. raSmith designed these crossings as well as retrofitted an existing wet detention basin to provide additional water quality benefits to the adjacent neighborhood. The pollutant removal benefits were evaluated using WinSLAMM.