Lake Irving TMDL Stormwater Retrofit and Iron Enhanced Sand Filter
Lake Irving, located in the City of Bemidji, is the first lake on the Mississippi River it's a shallow, natural lake. Water enters from the Mississippi River and flows though Lake Irving which outlets to Lake Bemidji 800 feet downstream. A portion of the City of Bemidji (866 acres), including city stormwater and industrial park runoff, drain to an unnamed stream which outlets on the southeast side of Lake Irving. Lake Irving was added to the 303d list in 2010 and a completed a TMDL in 2018 that found 736.34 pounds of phosphorus per year flowing to Lake Irving directly from the City of Bemidji. Based on the TMDL the goal is to reduce the contribution by 267.50 lb/yr of phosphorus. The project, based on a feasibility technical memorandum, will remove 221 lb/yr of phosphorus. The project has a unique set of circumstances where it has already been developed and restoration of Lake Irving can begin upon receipt of funding. Goals of this project include continued protection of the water quality of Lake Bemidji, increased local stormwater awareness, and collaborate with Enbridge, a new a partner who is willing to provide the grant match. Project planning began in 2014, when the Mississippi Headwaters Board completed a Stormwater Water Quality Best Management Practice Retrofit Analysis for Bemidji. The analysis was a tiered approach, starting with a review of existing spatial data and local knowledge identifying areas least likely to be conducive to retrofitting. The remaining catchments were designated Priority Management Areas (PMA) and modeled to estimate existing delivery of phosphorus and sediment. Based on this analysis, PMA 25 was targeted for further investigation and a feasibility technical memorandum was completed though the North Central Minnesota Joint Powers Board. This memorandum determined that the creation of an iron enhanced sand filter along with additional channel storage, culvert replacement, and re-vegetation yielding the greatest return on investment.
Marcey Westrick
[Projects and Practices 2020] (b) $16,000,000 the first year and $16,000,000 the second year are for grants to local government units to protect and restore surface water and drinking water; to keep water on the land; to protect, enhance, and restore water quality in lakes, rivers, and streams; and to protect groundwater and drinking water, including feedlot water quality and subsurface sewage treatment system projects and stream bank, stream channel, shoreline restoration, and ravine stabilization projects. The projects must use practices demonstrated to be effective, be of long-lasting public benefit, include a match, and be consistent with total maximum daily load (TMDL) implementation plans, watershed restoration and protection strategies (WRAPS), or local water management plans or their equivalents. A portion of this money may be used to seek administrative efficiencies through shared resources by multiple local governmental units. Up to 20 percent of this appropriation is available for land-treatment projects and practices that benefit drinking water.
This project had a feasibility study done in 2018. The project is estimated to prevent 221 pounds of phosphorus and 73,974 pounds of total suspended solids from entering Lake Irving on an annual basis.
LOCAL LEVERAGED FUNDS