The Riley Purgatory Bluff Creek Watershed District, together with the City of Chanhassen, have begun building a structure to treat stormwater in Lake Susan Hills West Park. The structure will clean stormwater by removing phosphorus. This nutrient is contributing to poor water quality in Lake Susan and can cause cloudy water and algae blooms.
The structure being built is called a “spent-lime treatment system.” It is one of several treatment methods that were considered. A spent-lime system was picked because it would have the smallest impact on the surrounding land and wetlands, and remove a large amount of phosphorous for the cost.
The site for the spent-lime system was identified in 2013 through a study that looked at different actions that could be taken to clean Lake Susan water. It is located near the pedestrian trail off of Lake Susan Hills Drive. During construction, the site will be accessed by the trail. The existing culvert under the trail will be used to divert water into the spent-lime system. Rainwater runoff from over 300 acres passes through this culvert before entering Lake Susan, making it an ideal location for treatment.
The construction area will be approximately 0.2 acres. Some brush will be cleared, but very few trees will need to be removed. This is another reason this site was chosen. After construction, the site will be restored with native plants. The image below shows a prediction of what the site might look like when everything is completed.
Questions or comments? Contact the district: 952-607-6481, firstname.lastname@example.org