Bank 1 Wetland Enhancement

The Tetonka Wetland Bank 1 is located in Minnehaha County southwest of Colton, South Dakota.  The banking site is ideally located to make a positive contribution to water quality within the Big Sioux River Watershed. The site lies within one mile of Clear Lake in the Skunk Creek subwatershed of the lower Big Sioux River Basin.

The wetlands and intermittent ditches/streams originally found on the site were functioning at a low level and the wetland areas were tilled annually or heavily grazed. Invasive weeds were common throughout the site. Intensive land use occurred immediately adjacent to both intermittent streams and resulted in high water temperatures and heavy silt loads. Perennial cover for wildlife was limited.

Existing wetlands were restored from row crops and pasture areas to palustrine emergent saturated, temporary, and seasonal wetlands dominated by native sedge, rush and grass species.  Upland portions of the banking site were restored to native prairie, and that native perennial vegetation improved the value of these areas as buffers to the site’s wetlands. Restoration efforts also established perennial, herbaceous vegetation adjacent to the streams.

The introduction of perennial, native cover to the site has improved the temperature and turbidity within both streams and enhanced the habitat for native fish and aquatic invertebrates. Buffers of native perennial vegetation also moderate the input of nutrients and particulates to the wetlands. Water storage within and exported from the site has been restored to natural levels.  Cattle are restricted from the site’s streams, and perennial, native vegetation has stabilized the soils.

The site is located outside of urban growth areas and in close proximity to Clear Lake and a large complex of non-farmed wetlands. The Fish and Wildlife Service maintains a waterfowl production area on the shores of Clear Lake, and two South Dakota Game Fish and Parks game production areas are adjacent to the lake. Game Fish and Parks also actively manages the fishery in Clear Lake. As a result of these management activities, this location provides optimal opportunities for the banking site to be used by waterfowl and other wildlife. Removing the current land use disturbances from the banking site and establishing native cover has enhanced wildlife habitat. Furthermore, restoring natural hydrology to the site has provided additional opportunities for resting, feeding, and/or nesting by breeding and migratory waterfowl. In a landscape context, the bank has enlarged the area of quality habitat and provided connectivity among existing habitats.