Dane County Flood Risk Reduction Project Marks Record Year
December 27, 2023
Ariana Vruwink, 608-267-8823
County Executive, Land & Water Resources
Multi-Year Initiative to Decrease Flood Risk Along Yahara Chain Removed Thousands of Trucks Worth of Sludge, Sediment in 2023
An innovative Dane County initiative aimed at reducing the risk of future flooding along the Yahara River Chain marked substantial progress in 2023, County Executive Joe Parisi announced today. Over the past year, Dane County’s Flood Risk Reduction Project removed 118,700 cubic yards of sludge and sediment accrued at the bottom of the Yahara River. For perspective, that’s roughly equivalent to nearly 10,000 dump truck loads removed in just the past year alone.
“One of the key takeaways from the severe flooding we saw just a few years ago was the extent of build-up in the bottom of the Yahara River and how it slowed our ability to not only store but also safely move high volumes of rain through our chain of lakes,” Parisi said. “Over many years run-off built up in the river, making it harder to maintain flow.”
Dane County experienced weeks of flooding in late summer of 2018, as repeated August thunderstorms dropped record amounts of rainfall in just a few hours. Given projections the region will see more significant rainfall events because of climate change, the county set out to take steps to prevent a recurrence of the flooding the area experienced.
“While the past couple of years have been drier than normal, we know climate-related cycles will lead to extremes and volatile, unpredictable swings in both temperature and precipitation,” Parisi noted. “That’s why it’s important we continue to prepare, re-double our efforts on resiliency, and be mindful of the impacts of our land use decisions relating to runoff.”
Dane County had two crews work through 2023 on two segments of the flood risk reduction project in the Yahara, and the result was the highest amount of sediment removed since the initiative began. Close to 19,500 cubic yards were removed in one stretch between Lake Waubesa and Lower Mud Lake. A secondary phase of hydraulic dredging focused on the river between Lake Kegonsa and Highway B down by Stoughton. 99,200 cubic yards of sediment were pumped out there. The work on this phase is expected to be completed next spring by Michels Construction, a private contractor.
Dane County has already begun construction of a large storage basin to hold water and sediment slated to be removed in the next phase of the project, set for a segment of the Yahara River between Dyreson Road and Lake Kegonsa. This new seven-acre basin is anticipated to be complete in the spring, with sediment removal starting next summer. It’s anticipated this round of work will take until 2025 to complete, and it’s projected to remove another 60,000 cubic yards of materials.
“This work is a hard slog, but we continue to make progress and are better prepared by the day for when the next round of heavy rains fall,” Parisi concluded.