Milford, Iowa - Garlock Slough Wetland Complex, on the southwest side of West Okoboji Lake, is a 900-acre mix of native remnant prairie, restored prairie, natural marsh and reconstructed wetlands protecting Iowa’s most valuable lake.
It filters 11 percent of the watershed through its 41 wetlands that make up 246 acres of the complex. In addition to water quality benefits, the area reduces soil erosion with restored prairie and shortgrass eskers on the ridges.
“It’s better for the lake, it’s better for wildlife – for the grassland birds, wetland birds - and it’s better for the overall area’s quality of life – for watching wildlife, for hunting, swimming, fishing,” said Chris LaRue, wildlife biologist for the Iowa Department of Natural Resources (DNR). “This is a perfect example of a water quality project coming together over time.”
The complex has expanded over the past 20 years and has resulted in improved water quality in Emerson Bay. A DNR and Ducks Unlimited water quality enhancement project likely set for 2022 will build on those benefits.
Contractors will add a concrete pad and small portable sump pump to the northwest corner of the 77-acre Garlock Slough that will allow the DNR to periodically lower the water level of Garlock Slough to enhance aquatic vegetation and to control rough fish populations.
The water will move west to a seven-acre wetland via low flow pumping then filter back into West Okoboji Lake through the canal that borders Emerson Bay State Recreation Area. A rough fish barrier will be added to prevent carp from entering the slough to spawn.
The project is estimated to cost around $300,000 and will result in improved aquatic vegetation for long-term water quality and habitat benefits.
The areas current mix of quality wetlands and prairie support two nesting pairs of trumpeter swans and is home to some of Iowa’s threatened or endangered species, including Poweshiek skipper, white lady’s-slipper, rattle milk vetch, Dion skipper, fries pondweed and water starwort.
Standing on a ridge on the west end looking east over the prairie, the wild bergamot is in bloom, and pale purple coneflower, compass plant, rattlesnake master and blazing star all stand out. Pheasants can be heard crowing.
“It’s a heck of a waterfowl complex under normal conditions,” LaRue said.
The complex is open to hunting except for certain areas that fall within the rule of no shooting within 200 yards of an occupied building. An award-winning bike trail within Hwy. 86 right of way runs along the south side of Garlock Slough that adds more recreational opportunity and aesthetic enjoyment of the complex.
Trail maintenance is the responsibility of the Dickinson County Trails Association.