Little Rock Creek, a cold-water trout stream in central Minnesota, is impaired due to the lack of trout and other cold water fish. The trout are absent because of high water temperatures, low dissolved oxygen and high nitrate levels, stressors caused from a lack of base flow and overuse of groundwater. This project continues a 2011 initiative to assist irrigators in the Little Rock Creek groundwater recharge area with managing the timing and amount of irrigation applied to their crops.
This project will reduce phosphorus loading from the watershed tributary to Silver Lake. The project includes a combination of structural water quality improvements in the SLV-10 subwatershed north of the lake, retrofits (including iron enhanced sand filtration) to the Silver Lake bioretention basin, small scale best management practices (BMPs) throughout the watershed, and educational signage in Joy Park. The elements of this project will reduce phosphorus loading to Silver Lake by a combined 15 pounds per year or 40% of the current watershed load.
At almost 4,000 acres, Trout Brook is the largest subwatershed in the Capitol Region Watershed District and the City of Saint Paul. The restored stream is part of the 42 acre Trout Brook Nature Sanctuary project, whose goal is to return the area back to some resemblance of its pre-industrialized valley of stream floodplain and wetlands. Monitoring results within the corridor show that phosphorus, sediments, bacteria, lead and copper are the pollutants of most concern.