Proposed redesign for Willow Creek focused on recreation, stormwater management | Higher education

Emptying directly into Lake Mendota, the sediment collected by Willow Creek through runoff has worsened the sandbar in University Bay. While dredging the sandbar is not currently on the table, Gary Brown, director of campus planning and landscape architecture, said management plans are currently focused on stopping sediment “at the source.”

“Our climate is changing and we continue to see more frequent rainfall and larger rainfall events,” Brown said. “As we look at stormwater management and trying to maintain the health of the Yahara Lakes system, this is just one piece in all of that but this is a very important piece.”

Stormwater management efforts include the creation of bioswales — concave marshy areas filled with native plants that retain and filter runoff. Bioswales slow the passage of runoff into Lake Mendota, allowing plants to take up some nutrients such as phosphorus, which helps plants grow but also spurs blue-green algae blooms. The remaining sediment will either settle in Willow Creek or be captured by the city’s existing “clean out structure,” which retains and filters stormwater.

Slowing runoff allows the water entering Lake Mendota to cool, which can also help curb algae blooms as blue-green algae grows more in warm water and rainwater is usually warmer as it leaves the atmosphere, Brown explained.