Green Lake, like many lakes in Minnesota, faces a phosphorus challenge. Excessive phosphorus in the lake adversely affects water quality and triggers algae blooms.
Shockingly, just one pound of phosphorus can grow 500 pounds of algae! Due to elevated phosphorus levels, Green Lake has earned a place on the Minnesota Pollution Control Agency’s impaired water bodies list.
Fortunately, there’s a solution to remove Green Lake from this list and curb its phosphorus levels – by implementing conservation projects in the watershed that feeds into the lake.
Isanti Soil and Water Conservation District, in partnership with the Green Lake Improvement District, received a federal grant to install projects that improve the lake’s water quality. Recently, the Isanti SWCD installed a wetland restoration to significantly reduce the amount of phosphorus draining into the lake.
Late this winter, a 1.7 acre wetland restoration was done on County Ditch 23 in Wyanett Township. A wetland restoration aims to revive former or degraded wetlands and restore them to their natural state.
Historically, many of Minnesota’s wetlands were filled or drained for development, transportation, and agriculture purposes. The restoration is a long time coming after a process of assessing the site, designing the project, and waiting for installation until the wetland is dry or frozen.
During installation, the site will be excavated to remove the fill and then reseeded with native plant species. The excavation process is extensive; for this site, approximately 100 dump truck trips are required to remove all the black dirt.
Fortunately, the removed soil is rich in nutrients and organic matter, which makes it valuable for crop cultivation.
Finally, when native vegetation is reestablished, the wetland will be in its natural condition and be able to provide robust environmental and ecological benefits.
Restored wetlands are vital in capturing stormwater, providing wildlife habitat, mitigating flooding, replenishing groundwater, and trapping sediment and nutrients. This wetland restoration site was strategically chosen to divert, capture, and filter rainwater runoff from County Ditch 23. During storm events, water will flow into the wetland, capturing sediments and nutrients that would otherwise reach Green Lake through the ditch.
With this service, this wetland will capture 51 pounds of phosphorus and 17 tons of sediment from entering Green Lake every year. That is enough phosphorus to grow 25,500 pounds of algae and enough sediment to fill five hot tubs!
The Isanti Soil and Water Conservation District has a goal of preventing 617 pounds of phosphorus from draining into Green Lake from the watershed. This project is a big step to get closer to that goal!
Funding for the project comes from the Rum River Watershed Partnership, a 16-year federal 319 grant, and donations from the Isanti County Sportsmen’s Club.
If you have land near Green Lake and are interested in helping improve its water quality, contact us! We have funding for a variety of conservation practices both in the Green Lake Watershed and elsewhere in Isanti County. Call us at 763-689-3271 to get started.
Most Popular
Comments / 0