West Fork Kickapoo Watershed
The storm event that led to the dam failures and this PLAN-EIS process for both watersheds is summarized on the Project History page.
West Fork Kickapoo Valley is located in the Driftless Area (unglaciated area) of western Wisconsin, characterized by steep, high bluffs and numerous coulee reentrants. Approximately 98 percent of the watershed area is in Vernon County, the remaining area is in Monroe County. The West Fork Kickapoo Watershed has an area of 75,387 acres (117.8 square miles) to the confluence with the Kickapoo River (a tributary of the Wisconsin River). The focused planning area for the PLAN-EIS is 63,761 acres (99.6 square miles) and includes the village of Liberty.
The first two watershed dams - Mlsna and Klinkner - were constructed in the West Fork Kickapoo Watershed under the Pilot Watershed Program in 1956. A multitude of land treatment measures and seven additional watershed dams were implemented under a 1961 Watershed Work Plan developed by the NRCS (formerly SCS). It was supplemented in June 1964 with recreational facilities, the deletion of a dam, and revised supporting tables. The Project Agreement was signed by the NRCS and the Vernon County Conservation District. Conservation Districts are no longer organized as a subdivision of state government in Wisconsin, but their primary functions were deferred to land and conservation committees under their respective County Boards.
The major problems in the watershed in 1956 and 1961were floodwater damages to crops and pasture, fences, farmsteads, machinery, buildings, and livestock, county and township roads and bridges, and the village of Liberty.
Project measures implemented under the 1961 Watershed Work Plan include a multitude of land treatment practices to reduce erosion and improve the hydrologic condition of watershed; and 7 flood control dams with a total capacity of 3,652 acre-feet to regulate flood flows from 30.73 square miles, or 31 percent of the watershed above the village of Liberty. The benefit-cost ratio for the project was about 1.2:1. With the two dams built under the Pilot Watershed Program, the runoff from 34.6 square miles or 35 percent of the watershed above the village of Liberty is controlled.
On the night of August 27, 2018, two watershed dams over-topped and two dams failed; Jersey Valley Dam (WFK 1) and Mlsna Dam (WFK Pilot). Rainfall amounts up to 11 inches were reported on the night of August 27 and early morning of August 28. Additional rainfall amounts up to 7 inches were reported in the afternoon of August 28, after the dam failures.
The dams failed (breached) along the interface between the earth-fill and highly jointed Jordan sandstone bedrock. Each breach extended full depth to the valley floor. No one was injured or killed. Large debris fields were observed downstream of the dams for about ¼ mile. Agricultural lands and road crossings were damaged. Nearly identical dam failures were observed after the same storm event in the adjacent Coon Creek Watershed at Luckasson Dam (CC 21), Blihovde Dam (CC23), and Korn Dam (CC 29). Historic failures of similar nature are also mentioned in SCS investigation reports at Dahlen Dam (CC41) after a 5 to 6-inch rainfall on July 1, 1978; Clockmaker Dam (WFK16); and Bad Axe Watershed Sites 12 and 33.
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1961 Watershed Work Plan (link coming soon)