The project will improve ecological functions along this reach of the creek and downstream Lake Susan by reducing stream bank erosion, reconnecting the creek to its floodplain, restoring habitat, and promoting diverse vegetation. Reducing the sediment and phosphorus load to Upper Riley Creek will also help restore and protect all downstream waterbodies, including Lake Susan, Rice Marsh Lake, Lake Riley and ultimately the Minnesota River. Project improvements will be planned and implemented in coordination with opportunities to preserve and enhance maintenance access to public infrastructure features such as stormwater outlets.
The total reduction in pollutant loading as a result of stabilizing this reach of Upper Riley Creek is estimated as 470,000 pounds per year of total suspended solids (TSS) and 250 pounds per year of total phosphorus (TP). These values are representative of an erosion rate of approximately 0.10 to 0.25 feet per year for the stream banks. The reduction in TSS and TP loading is a critical component for improving the ecological health of the aquatic ecosystems (both Upper Riley Creek and Lake Susan) and essential to potentially removing Lake Susan from the MPCA’s impaired waters list.
The project design focuses on improving the ecosystem by stabilizing the creek while also improving degraded habitat conditions along the creek. This section of creek has a primarily sandy/silty streambed with limited variability in depth. The project would provide greater stream depth variability through the addition of pools and riffles, more channel bed substructure types, and varied channel velocities (water flow speed). These improvements will enhance in-stream habitat features to benefit macroinvertebrates and fish. Improvements will also provide better floodplain connectivity for Upper Riley Creek resulting in enhanced habitat near the stream.
The Upper Riley Creek Ecological Enhancement Project is currently in the design phase with final design scheduled for completion in late summer 2023. Bidding to select a contractor to build the project will occur in winter 2023/24. Construction is planned to begin in late summer or early fall of 2024.
PROJECT OPEN HOUSE
Attend to view final project design, talk to project managers, and discuss potential property impacts.
When: 3 - 5 pm, October 23, 2023
Where: RPBCWD Office, 18681 Lake Dr E, Chanhassen
RSVP: LForbes@rpbcwd.org or 952-607-6481
Design to be completed in 2023. Construction planned to begin in late summer or fall 2024.
Terry Jeffery, District Administrator
952-607-6512 ext. 1
Liz Forbes, Communications Manager
952-607-6512 ext. 5
City of ChanhassenWater Quality Improvement Projects