Brown's Creek Watershed District and Washington County worked together to retrofit McKusick Road during the 2017 road improvement project, providing water quality treatment to this 5,900 foot section of McKusick Road that previously discharged 25.5 acres of untreated stormwater to Brown's Creek, a designated trout stream listed as impaired due to high thermal and total suspended solids loadings. The project was completed June-August 2017.
What did we construct?
We analyzed other options to treat stormwater from this drainage; however, infiltration practices were not feasible due to tight soils and limited road right-of-way. In the end we were able to do the following:
Retrofit existing 7 catch basins with Momentum Baffles and Skimmers
Install three 40 foot x 5 foot diameter underground water quality tanks (Prinsco Water Quality Units) to trap sediment and floatables from the roadway
How does the project help Brown's Creek?
Brown's Creek was improved by reducing total suspended solids by 3521 pounds per year (84% removal) and reducing total phosphorous by 7.77 pounds per year (51% removal). Since Brown's Creek flows directly into the St. Croix River, this was also a reduction of 7.77 pounds per year of total phosphorous to the St. Croix.