GREEN INFRASTRUCTURE FIGHTS POLLUTION, HELPS REDEVELOPMENT
Grassy, flowering spaces absorb heavy rains before stormwater runoff can inundate sewer
Over the next year, six Milwaukee Public Schools properties will together have over 3 acres of pavement replaced by trees, native plants and other features designed to soak up rainwater like giant sponges. That will help keep polluted stormwater from flowing into rivers that empty into Lake Michigan — as well as freeing up more space in the deep tunnels system designed to reduce sewage overflows. The improvements coming to those MPS sites are known as “green infrastructure.”
Green infrastructure also helps control flooding while spurring the creation of wildlife habitats, recreational areas and urban redevelopment projects.
It continues to grow throughout the Milwaukee area — including a high-profile project to be unveiled this spring beneath a busy freeway stretch on downtown Milwaukee’s west side.
“It’s really this unique approach that provides a lot of benefits,” said Kevin Shafer, executive director of the Milwaukee Metropolitan Sewerage District.
The district, which is funded through property taxes and user fees, is spending $10.4 million on green infrastructure in 2021.
Green infrastructure takes several forms. It can include rain gardens, where a sunken area in a home’s backyard, planted with flowering perennials, soaks up rainwater that runs off
the roof.
Those are similar to bioswales: troughs that use plants to absorb stormwater runoff from parking lots before it reaches the street — and eventually rivers and streams.
Other projects include green roofs, when grass planted on the roofs of apartment buildings, office towers and other commercial and civic properties help soak up rainwater.
Related projects include the sewerage district’s “greenseams” program.
The district since 2001 has spent $26.8 million (including $6.7 million in state grants) buying 4,676 acres of flood plain along the Milwaukee, Menomonee and Kinnickinnic rivers and their tributaries, as well as the Oak Creek and Root River watersheds.
That prevents development, preserves wildlife habitats and reduces both flooding and stormwater that ends up in the deep tunnels.
The deep tunnels system has reduced sewage overflows into Lake Michigan from 50 to 60 annually, before it was built, to around two annually since the tunnels began operating in 1994.
Overflows can still occur when unusually heavy rains cause the tunnels to fill up before the sewage can be treated.
The tunnels were designed before the green infrastructure movement started.
The district had no green infrastructure capacity in 1998, when Shafer was hired as its engineering chief.
“Green infrastructure was not talked about on the national level,” he said.
Then, the district saw an unusual number of sewage overflows in 2001 and 2002, he said.
Those overflows, which forced summer beach closings, were happening in part because of intense rainstorms linked to long-term climate change.
So, the district worked with the Southeastern Wisconsin Regional Planning Commission to create an area watershed plan.
“We had to do more than just manage overflows,” said Shafer, who was promoted to executive director in 2002. “We need to manage stormwater better.”
Reducing stormwater entering sewers
That brought an increased focus on reducing stormwater from entering the sewer system — creating more space to store sewage before it’s treated.
A plan approved in 2010 outlined a goal of absorbing the first half-inch of rain throughout the district’s 411square-mile region by 2035.
That translates to 740 million gallons of rainwater annually. By comparison, the deep tunnels system can store up to 521 million gallons of sewage and polluted stormwater.
Meanwhile, the Common Council and Mayor Tom Barrett in 2018 approved a separate green infrastructure plan for the city. It calls for adding 36 million gallons of stormwater storage capacity by 2030.
The district, which includes Milwaukee and 27 other area communities, has a goal of adding 50 million gallons of stormwater storage capacity through green infrastructure under its latest operating permit issued by the Wisconsin Department of Natural Resources.
To help reach its goals, the district is helping fund projects such as the latest round of green infrastructure at six MPS sites.
That plan won Common Council approval on Feb. 9.
It calls for removing asphalt and concrete pavements mainly located in school playgrounds at Allen-Field School, 730 W. Lapham Blvd.; Academy of Accelerated Learning, 3727 S. 78th St.; Bay View Montessori School, 619 E. Dover St.; Burnham Playfield, 1755 S. 32nd St.; Escuela Fratney, 3255 N. Fratney St.; and North Division High School, 1011 W. Center St.
Those hard surfaces will be replaced with native landscaping, trees, bioswales, cisterns, permeable synthetic turf and porous pavement.
That work, to be done this year, will
together create nearly 312,000 gallons of rainwater storage capacity.
The district is paying up to $551,464 for the projects, or 75% of their costs.
The remaining funds are coming from the city, various state and federal agencies, the private Fund For Lake Michigan and contributions raised by the MPS Foundation, said Angeline Koch, MPS sustainability project specialist.
Those other sources are paying for upgraded play spaces and outdoor environmental education classrooms that are replacing the asphalt and concrete, Koch said.
This marks the third consecutive year of green infrastructure work at MPS sites.
Four such projects were done in 2019, with another five schools adding green infrastructure last year, Koch said.
Suburban projects coming
Green infrastructure projects also could be coming to suburban school districts, Shafer said.
Meanwhile, a more high-profile project was largely completed in 2020 beneath I-794 on downtown’s west side.
It covers around 16 acres between West Clybourn Street and West St. Paul Avenue, from North Sixth Street to North 12th Street — formerly used as a camp by homeless people.
The project’s $2.8 million first phase creates drainage swales, retention basins, permeable walking paths and deep-rooted native plants that store up to 292,900 gallons of rainwater. Most of the improvements have been completed, with the plants coming this spring.
A future phase could bring public recreation or park space, according to the Milwaukee Department of Public Works.
There’s no timetable or cost estimate yet available because ideas are still preliminary. One conceptual proposal calls for a mountain bike course.
Shafer said the project, funded by the district, could be duplicated beneath other freeway overpasses.
“That’s a road map for the future,” he said. “There’s a lot of places in this area where we could do something like that.”
Green efforts spurred development
Green infrastructure also helps encourage commercial redevelopment projects.
That includes Milwaukee’s Menomonee Valley Industrial Center.
That city-developed business park, east of American Family Field, includes Menomonee Valley Community Park — a soccer field that doubles as a stormwater retention site.
That central retention site made it less costly for Palermo Villa Inc., Charter Wire and other businesses to develop new buildings without separate stormwater basins.
The city took a similar approach when it developed Reed Street Yards business park, which is south of the Menomonee River Canal between South Third and South Sixth streets.
The green infrastructure helped attract Zurn Industries LLC, which opened its headquarters in 2016, and a pending plan by Rite-Hite Holding Corp. to develop a corporate campus, said Sam Leichtling, the Department of City Development’s long-range planning manager.
Other examples include planned RiverWalk extensions along the Menomonee and Kinnickinnic rivers, as well as green space improvements coming to the North 30th Street Corridor, Leichtling said.
The growing number of green infrastructure projects is important — particularly as climate change brings more flooding and other natural disasters, Shafer said.
“It started with science,” Shafer said. “Now, it’s a reality that everyone understands.”
“It started with science. Now, it’s a reality that everyone understands.” Kevin Shafer executive director of the Milwaukee Metropolitan Sewerage District