There's growing recognition that the best way to cleaner lakes is to improve the watershed around them--including more infiltration of rainwater, less erosion, and more biodiversity.
The Friends of Lake Wingra undertook a survey of the watershed. One finding was that swales--shallow grassy depressions used to manage stormwater--were present everywhere and could be modified to improve infiltration. Every school we surveyed had swales, often in areas that have no other use.
Swale at Midvale School during a severe storm.
Swales are linear depressions in turf, usually in sunny locations. With little effort, they can be turned into rain gardens by the creation of shallow dams, then planted with native prairie species.
What's needed is a test of this concept, to see if we can find a method that requires minimal labor and expense. We hope to demonstrate that benefits will outweigh any increased maintenance or loss of open lawn.