By Gregg Hoffmann
CASHTON – Two environmental engineering firms are scheduled to tour the Jersey Valley Lake area Monday in preparation for submitting bids for repairs of a dam at the lake, which suffered a severe fish kill in 2005.
Ayers and Associates of Eau Claire and STS Consultants from Madison have been chosen to present bids to the committee to fix fissures in the dam and lake.
A subcommittee of the Vernon County Land and Water Committee will consider the bids and announce the winner on Feb. 8. That committee consists of county conservationist Kelly Jacobs, Dam Project Manager Phil Hahn, committee members Richard Hansen and Jan Ihle, and technical representatives from the Department of Natural Resources (DHR) and National Resources Conservation Service (NRCS).
Jersey Valley was one of several waterways in the state affected by manure runoff in March of 2005. Tests by the DNR fisheries staff showed the highest recorded level of dissolved oxygen in the water was one part per million. Trout generally need 5 parts per million of oxygen in water to survive. Warm water species usually need at least 3 parts per million oxygen for survival.
The lake is fed by runoff from a watershed covering about 12 square miles. It is located at the head waters of the West Fork of the Kickapoo River, which is a trout stream. The DNR has said no fish kill has been located in the trout stream.
But, the flood control dam on the lake was found to be in disrepair and fissures were found in what is called the “clay blanket” of the lake.
In 2000, the flood control dam needed to have the clay blanket covering one side of the lake replaced, because the existing blanket was allowing water to seep through the dam itself.
During excavation for that project, a long, deep crack was discovered at the base of a rock abutment. River City Concrete of Westby was contracted by the county to bring in the concrete to fill the crack. The clay blanket was eventually repaired.
Another clay blanket fix has been authorized by the DNR, but rejected by the NRCS. Last month, Hansen received a letter saying if the county chooses to fix Jersey Valley using the clay blanket option, NRCS will terminate its maintenance agreement with the county, which then would have to bear all of the costs of that fix.
The committee told the NRCS the county needs to get more firm numbers from an engineer before it can decide if it would like terminate its relationship with NRCS.
County officials have budgeted $100,000 for repairs and maintenance at other dams in the county, but hope to get state or federal help in repairing the Jersey Valley dam. No county money has yet been designated directly for that project