County outlines dredging plan for lake: 5.7 acres, beach work and spoil options discussed

Vernon County staff presented an update on a planned dredging project for a county lake (described in materials as the northern and eastern lobes). Staff said permits from state regulators and the U.S. Army Corps of Engineers have been part of the planning process and that public notice for comment has been issued.

The plan discussed by staff proposes dredging approximately 5.7 acres in total, with portions currently exposed as sediment flats (about 3–3.5 acres with no standing water). Staff described a targeted depth progression: nearshore areas to roughly 6 feet deep and out toward the main channel to 10–12 feet. A beach improvement was described for the northern lobe: a 285-foot-long by 53-foot-wide beach area with roughly 12–15 feet of the width extending onto land and the remainder sloping into the water.

Staff described the beach cross-section and materials: geotextile, an 8-inch lift of breaker run (about 22 truckloads in their estimate), and a 12-inch sand lift (about 33 truckloads). Options for removing dredged sediment include a nearby old quarry by Springville and a second site (Smallville quarry on Highway 82 toward DeSoto); staff said sediment testing showed elevated phosphorus, nitrogen and potassium levels and that one spoil site had historically produced poor results when dredged material was placed on farm fields.

Staff advised that the operation would likely require drawing down the lake about 7–8 feet, a drying period of roughly two weeks, and either mechanical dredging or suction dredging depending on bidders. A prequalification meeting for bidders was discussed to ensure contractors have dredging experience. Staff said the project is not imminent and that a likely season would be late fall once camping season is over; committee members confirmed the work would more likely occur in 2025 rather than this calendar year.

Committee members discussed catchment improvements upstream, potential interim measures such as trap maintenance or localized scooping, and the limits of such measures given watershed size and urban runoff. Members also raised questions about long-term spoil-site stability and county responsibility for spoil sites, with staff saying the county would likely retain responsibility for the spoil site for an initial multi-year period (two to three years) to allow settling, drying and further reclamation.