Shorewood is installing rain gardens to help purify rainwater runoff before it enters the village’s stormwater sewer system.

Village officials approved Monday installing two bio swales near the intersection of East Kensington Boulevard and North Wildwood Avenue, as part of Shorewood’s ongoing plan to revamp its outdated sewer system. Officials started sewer and road improvements in the northwest portion of the village after approving $7 million in projects in March.

The garden basins will cost $16,500 and be installed by Pewaukee-based Globe Contractors.

According to a memo from Shorewood Department of Public Works Director Leeann Butschlick, "surface rain water will enter the rain gardens through a curb opening and plantings in the gardens will filter impurities as the water flows slowly through the basin before being routed back into the street."

The basin will also be built to divert excess water around the basin and directly into the storm sewer system.

"This is a part of our green commitment within the village," Trustee Jeff Hanewall said.

Wildwood Avenue is wide enough that there’s plenty of room to install the garden basin without losing any street parking.

As an alternate project when work in the area was authorized in March, four rain gardens were originally proposed — one at each corner of the intersection — but village staff said only two were necessary to handle water flow.

"Staff has now come back and done some further analysis and they recommend just the two additions," Hanewall said.

Trustee Michael Maher said he wanted to ensure residents in the area were adequately forewarned about the project. Village Manager Chris Swartz said letters were mailed to neighbors about a week ago.