DES MOINES – A second and final season of dredging on Black Hawk Lake, located in Sac County, will start this week and is scheduled to end in early June. An additional two to three weeks of site clean-up and contractor demobilization will follow the dredging work.
Boaters and other lake users should use caution while navigating Black Hawk Lake during the dredging season. The dredge barge and pipeline will be clearly marked with buoys and lights. Maintain a minimum of 200 feet distance from all equipment and pipelines. Do not attempt to cross the dredge pipeline, even if it is submerged.
The dredge will move across the lake slowly as it removes silt. The pipeline will follow behind the dredge, generally running from the barge toward Cottonwood Point. The pipeline will stay close to shore from Cottonwood Point and run westward along the south side of the lake where it crosses under Quincy Avenue. From there, it will run across the Inlet Slough and enter into the ROW at 350th Street and continue on to the spoil site. Water will also be returned near the bridge crossing at 350th Street.
The dredging work planned for Black Hawk Lake will improve overall water quality, fish habitat and recreational opportunities. An area approximately 174 acres in the eastern main basin of the lake will be deepened to nine feet, removing about 750,000 cubic yards of material from the lake. Dredging will help manage aquatic vegetation in the main basin of the lake, reduce re-suspension of sediments due to wind and wave action, and remove high-phosphorus sediments.