Lakeville, MN – Foxborough Stormwater Pond

CHALLENGE

The City of Lakeville has several areas that were developed before the implementation of modern stormwater rules. As a result, these residential neighborhoods and commercial districts can have relatively large areas that do not have stormwater features that manage runoff rates, provide flood storage, or provide water quality treatment. There was a 220-acre watershed with residential land use that was discharging directly to North Creek without any stormwater treatment. The City desired to develop an improvement project that would reduce runoff rates to North Creek to help address a downstream flooding issue while also improving the water quality of the stormwater entering the creek.

SOLUTION

A feasibility study was completed to evaluate options for treating stormwater from the residential neighborhood. The study evaluated several concepts and ultimately identified a new stormwater pond with a sand filter bench as the most cost-effective project. Initial design plans were used to apply for grant funding for the project.

OUTCOME

The City and the Vermillion River Watershed submitted a grant application for the project, which was awarded $350,000 in Clean Water Fund dollars. Moore was contracted by the City to complete the final design as well as lead the public bidding, contractor management, and construction oversight for the project. The pond is located on City Park property within a floodplain. Moore used the City’s XPSWMM stormwater model to evaluate the potential impacts to the floodplain and complete a “no rise” analysis permit the project. The final design included a one-acre pond with a new outlet control structure to regulate runoff into North Creek. The pond provides water quality treatment to protect North Creek, with an estimated removal of 18 tons/yr of total suspended solids and 32 lbs/yr of total phosphorus. Construction was completed in August 2023.