Members of the Friends of Twin Lakes spent months researching information about Twin Lakes and the surrounding watershed area from numerous sources, including the Town of Warren, Village of Roberts, WI DNR, US Gelological Survey, St. Croix County, UW River Falls, National Weather Service, the National Oceanic and Atmospheric Administration, and a local hydrologist. This information was combined to develop a fairly detailed data model of lake behavior over a 43 year period between 1974 and 2017.
Our data model clearly demonstrates that lake levels in Twin Lakes have been on an overall rising trend for the entire period. Despite the observed wide swings in lake elevation over the years, the overall trend has been one of slowly increasing lake elevation. This rising trend continued until the critical flood stage was reached in 2015, hastened by the above average rainfalls. The rising trend persists, and lake levels will continue to rise unless changes are made in how water entering these small glacier basin lakes is managed.
The consistent, long-term, primary contributing factor to Twin Lakes’ inability to dissipate the volume of incoming water has been, and continues to be the wastewater treatment plant operated by the Village of Roberts, which pumps water from a deep well aquifer out to the Village, then processes the returned wastewater and discharges it into the lakes. This contributes about 100,000 gallons per day of new water to the lakes. When combined with the other natural sources, the lakes cannot dissipate the total volume of water through their natural processes. This has caused the lakes to reach flood stage, and fill the valley to the north of West Twin Lake, causing extensive property and infrastructure damage.