Accelerated Shallow Lake Restorations and Enhancements
Ducks Unlimited enhanced 6,882 wetland acres through the bio-engineering and installation of water control structures on managed shallow lake outlets for Minnesota DNR, and protected 76 wetland and 103 upland acres on a shallow lake through a purchased conservation easement.
About the Issue
As some of the only wetland basins that remain in prairie Minnesota, shallow lakes and large wetlands throughout southern and western Minnesota have become degraded due to high, stable water levels, altered natural hydrology due to highly drained and intensively cultivated watersheds, lack of natural fish winterkill, and invasive fish (including carp) that have increased access and overwinter survival due to high, stable water levels and manmade drainage systems through which they can now travel. These factors combined with naturally fertile prairie soils result in turbid water conditions over prolonged periods which reduce aquatic plant and invertebrate abundance upon which wetland wildlife depend in our remaining prairie wetlands and shallow lakes. The result is degraded wetland conditions that do not provide the aquatic food resources wetland-dependent wildlife, especially waterfowl, require as they move through and attempt to breed in Minnesota. The lack of high quality, productive wetland habitat is especially problematic for diving ducks and brood-rearing ducks which are fully dependent on wetlands and shallow lakes for all of their food resources.
The huge watershed changes in Minnesota’s agriculture-dominated prairie landscape that are largely beyond the control of conservationists leave agency wildlife managers with few options to improve and protect our remaining public water wetlands and shallow lakes. These tools primarily include acquiring and restoring land around our remaining wetlands and shallow lakes to buffer them from the effects of highly degraded and drained agricultural landscapes, and actively managing water levels in them to periodically induce temporary drought conditions to winterkill fish and rejuvenate the aquatic ecology of aquatic plants and invertebrates in them upon which waterfowl and other wetland-depending migratory birds rely.
Through our Living Lakes Initiative, Ducks Unlimited (DU) strives to help Minnesota Department of Natural Resources (DNR) and U.S. Fish & Wildlife Service (Service) to improve and protect our remaining shallow lakes and large wetland marshes. The goal of this Outdoor Heritage Fund (OHF) grant-funded program was to support DU wetland bio-engineering assistance to help the Minnesota Department of Natural Resources (DNR) and U.S. Fish & Wildlife Service structurally improve shallow lakes outlets by designing and installing new water control structures used to enhance the aquatic habitat quality of wetlands throughout southern and western Minnesota. DU biologists and engineers worked together with Minnesota DNR shallow lake program and area wildlife managers alongside Service biologists to design and construct water control structures with fish barriers that allow managers to enhance water quality and wetland habitat conditions for wildlife through temporary water level draw-downs. DU also protects private shallow lake shoreland on managed shallow lakes by securing a conservation easement held and enforced by DU.
In partnership with Minnesota DNR, DU designed and implemented eight shallow lake enhancement projects that improved 6,882 acres through the bio-engineering design and installation of water control structures and pumps equipped with fish barriers features. Minnesota DNR wildlife field staff used these structures to conduct temporary water level draw-downs to simulate natural drought conditions that winterkilled invasive fish (especially carp), consolidated sediments and nutrients, and rejuvenated the aquatic ecology of shallow lakes. These capital investments will last for decades, and will continue to be used periodically by Minnesota DNR wildlife field staff to manage and further enhance shallow lake habitat through annual state duck stamp funding.
The shallow lakes enhanced through this grant include 316-acre Jennie Lake in Douglas County, 4,076-acre Lake Christina and Lake Ina complex in Douglas County, 1,166-acre Rice Lake in Faribault County, 218-acre Ash Lake in Grant County, 165-acre Cory Lake on Hamlin WMA in Lac qui Parle County, 171-acre Round Lake on Shetek WMA in Murray County, 330-acre Smith Lake in Wright County, and 440-acre Curtis Lake in Yellow Medicine County. In addition, DU also engineered new water control structures for the Service on Rydell National Wildlife Refuge and for the Minnesota DNR on Malardi state Wildlife Management Area (WMA) that will be installed through future 2010 and 2012 OHF grants to DU after permits and funding have been secured. Finally, DU also secured a purchased conservation easement on Fish Lake in Stearns County that permanently protects 179 acres in perpetuity, which DU will annually monitor and enforce with stewardship endowment funding provided by the landowner.