Using A Watershed Approach To Restore Area Lakes

On Friday, January 27, the Comfort Lake – Forest Lake Watershed District broke ground on a $536,605 wetland restoration project in southern Chisago County that will ultimately improve water quality in Moody Lake (Chisago Lake Twp.) and Bone Lake (Scandia). The project will serve as an example for how to work at a watershed scale, as well as how to target water quality improvement projects to get the biggest bang for the buck.

Project partners gathered on site near Moody Lake for the project groundbreaking ceremony last Friday.

The district began a five-year project to improve Bone and Moody lakes in late 2010 when it harvested more than 23,000 pounds of carp from Bone Lake and 3,600 small bullheads from Moody Lake. In 2012, the district installed low-velocity fish barriers to prevent rough fish from migrating in and out of the two lakes. Last year, the district installed a winter aeration system in Moody Lake to prevent winter fish kills and help keep the bullhead population in check. This year’s wetland improvement project will keep 445 pounds of phosphorus out of Moody Lake each year, which is 80% of the reduction needed to nurse Moody back to good health and prevent excessive algae growth.

Carp harvest in Bone Lake 2010.

Though Moody is a small lake, only 34 acres in size, it is located at the headwaters of the Comfort Lake – Forest Lake watershed. From Moody, water flows downstream to Bone Lake, Comfort Lake, the Sunrise River, and eventually the St. Croix River. Several years ago, the watershed district completed a multi-year diagnostic study to identify the biggest sources of nutrient pollution for Moody Lake and prioritize the most cost-effective practices and best locations for lake improvement projects.

Water monitoring conducted in 2014 identified the northwest portion of the Moody Lake watershed as a phosphorus hotspot. Though only 25% of the water flowing into Moody Lake comes from that area, it supplies 66% of the phosphorus. The district realized that three wetlands in this area were sending large amounts of phosphorus downstream into the lake. The discovery was surprising because wetlands usually act like kidneys, helping to filter out excess nutrients and pollutants. These three wetlands, however, had become super-saturated with phosphorus and were no longer functioning like a filter.

Normally, wetlands help to filter pollutants before they flow to lakes and rivers but the wetlands north of Moody Lake are super-saturated with nutrients.

To restore the Moody Lake wetlands, the watershed district will excavate and remove nutrient-rich sediment, plant buffer strips to protect the wetlands from erosion and runoff pollution, and install a fence around the two northernmost wetlands to limit cattle access. A refurbished cattle crossing will be installed to allow cattle to travel through the wetland without trampling the vegetation, and the cattle will also have access to water in a feed lot which is not part of the wetland. The landowner with the cattle has also worked with the Chisago Soil and Water Conservation District to prepare a managed rotational grazing plan for his property.

The Moody Lake wetland improvement project will be paid for in large part by a $429,284 Clean Water Grant from the Minnesota Board of Water and Soil Resources, as part of the Legacy Amendment. In addition, the watershed district received a $78,028 EPA Clean Water Act Section 319 grant, and will also contribute $29,293 in local funds from the district’s capital improvement fund. In addition to protecting downstream lakes and rivers, project staff anticipate that the wetland enhancements will improve habitat for waterfowl and wildlife in the area. The project will be completed by the end of March.

For more information about the Comfort Lake – Forest Lake Watershed District, visit www.clflwd.org or call (651) 395-5850.