Project Update: BSU Subsurface Stormwater Treatment Project

Over 10 years ago, we worked on a project with the Mississippi Headwaters Board to hire an engineering firm analyze stormwater needs and opportunities in the Bemidji and Irving watersheds. There were several potential projects identified that would have a substantial effect on reducing the Phosphorous loading to those lakes from stormwater. This project, BSU Subsurface Stormwater Treatment, is one of those identified in the study. It includes a 92-acre drainage area that lacks stormwater treatment prior to entering Lake Bemidji. After identifying the project, the SWCD worked with Bemidji State, City of Bemidji, Beltrami County, and numerous agencies to plan and implement the project.

The total project cost is funded with funds coming from 6 different grants administered by the SWCD and matching funds from Enbridge. Moore Engineering designed the project and Casper Construction is completing the construction. Essentially, the project involves cutting the city stormwater pipe and redirecting the stormwater to an underground treatment/infiltration basin and then reconnecting the pipe to the end of the underground basin for any overflow. The project is designed to treat all the stormwater from a 1–2-inch rainfall event over 24 hours and infiltrate that water into the ground. Any additional rain that isn’t able to infiltrate in that timeframe will be returned into the existing stormwater pipe and discharge in Diamond Point Park just as before. The BSU Subsurface Stormwater Treatment is designed to reduce 58 lbs of Phosphorus, 22,800 lbs of Total Suspended Solids, and 256 lbs of Nitrogen per year from entering Lake Bemidji. This is approximately 25% of the 10-yr goal identified in the One Watershed One Plan for Phosphorus reduction in Lake Bemidji.

The construction is going extremely well, and we anticipate substantial completion of the project around the end of June. Upon completion of the project, the area will return to the original use as athletic practice fields and intramural fields. It’s great to see when different entities in our community work together for a common goal to protect our crown jewel of Lake Bemidji.