Analyzing the Impacts of a Retrofit Detention Basin Flow Control Strategy on Biodiversity in an Urban Stream System

Protecting biological diversity of a stream system while supporting development and growth is critical to sustainability. To this end, the City of Lenexa, Kansas has embarked on the Eastern Lenexa Detention Study. The study focuses on 1017 acres (1.6 sq. mi.) of Little Mill Creek watershed in Lenexa, Kansas, a Kansas City suburb. Little Mill Creek drains to Mill Creek, which is listed as an impaired water body under section 303(d) of the Clean Water Act. Water quality impairment parameters include chloride, fecal coliform bacteria, and biology. This study examined whether modifying 16 existing detention basins to capture and detain smaller storm events would significantly increase biological diversity and reduce erosion potential within Little Mill Creek. The study used biological data and discharge measurements collected at 11 sites within and near Little Mill Creek to develop linkages among hydrologic and biologic metrics.