NE 36th Street Sedimentation Basin and Stormwater Wetland Project
The project is located at an urban and rural boundary, which will provide benefits to residents throughout watershed. This project will utilize a pre-treatment sedimentation basin and a stormwater wetland to address sediment and nutrients in stormwater runoff that would otherwise flow untreated into Fourmile Creek.
The City is widening the bridge that crosses Fourmile Creek located at NE 36th Street. Currently, stormwater from the street and surrounding neighborhood enters Fourmile Creek without any treatment. This subwatershed of Fourmile Creek is approximately 55 acres and is a mix of single family homes, multi-family homes, commercial properties (church), and undeveloped areas (City Park). As a part of the overall project, stormwater runoff from this subwatershed on the east side of Fourmile Creek will be diverted into a sedimentation basin and wetland for treatment. NE 36th Street is heavily traveled in Ankeny and the wetland location is visible from the street and trail. It is situated along the drive to the Outdoor Education Center, which will provide access for educational programming.
Finally, this project is being implemented because it aligns with the goals and objectives of the Fourmile Creek Watershed Management Plan finalized in April 2015. The final plan can be found here. Even though Fourmile Creek is not a direct drinking water source, there is still a pollutant concern due to human contact with the water. This is of particular concern in the creekside parks, greenbelts, and recreational trails. Fourmile Creek has been shown to have increased bacteria levels and sediment loading, in addition to elevated levels of phosphorous and nitrogen. Since Fourmile Creek flows through rural and agricultural areas, but also the largest urban area in the state, residents in and visitors to the Fourmile Creek Watershed will benefit from water quality and quantity improvements. In addition, there is a plan to establish a greenbelt along Fourmile Creek to the Des Moines River confluence, where many visitors will be in contact with the water.
The City of Ankeny has a goal of improving the watersheds within its City limits, being good stewards of our land and water, and being good upstream neighbors.