Birch Lake Stormwater Retrofits
Projects and Practices 2016: Laws of MN 2015 First Special Session Chapter 2, Article 7, Section 7
Phosphorus is the primary pollutant of concern, and the current phosphorus loading capacity of 267 lbs/yr is equal to the current phosphorus budget. Therefore, no increase from current phosphorus loading levels is allowable, and the current TMDL prescribes a 26 lb/year reduction as a margin of safety. This project proposes to reduce the load from a highly impervious area that slopes directly into the lake from 11 lbs/yr to 3 lbs/yr.
This project resulted in an estimated reduction of 8 lb. of phosphorus per year
LOCAL LEVERAGED FUNDS
The funds requested will provide Big Lake Township with the technical and financial assistance necessary to retrofit up to six locations for stormwater treatment practices within the direct drainage area of Birch Lake, an impaired water body which is very close to meeting state standards. The projects have been identified as high priority in several water quality plans including a TMDL, a subwatershed assessment, the County Water Plan and the Mississippi River (St. Cloud) WRAPS. Five retrofit locations are planned along 224th avenue, this road currently collects runoff from surrounding properties and directly drains into the lake. Projects to be implemented on 224th avenue include modification of township right of ways to increase their capacity to hold and infiltrate water as well as the reshaping of the road to divert water into infiltration trenches. One retrofit project will be located at the township boat landing located on 159th street. The boat landing will be modified to capture and treat stormwater. Should additional funds remain after the township projects are implemented, the SWCD will contact residential land owners to inquire about implementation of additional stormwater reduction projects which are also identified in existing plans.