How Green Infrastructure Helps Communities Manage Stormwater

05/21/26 11:30:am

In the Milwaukee area, rain can add up very quickly. We saw this firsthand during the August 2025 floods and again during the heavy rains in April 2026, when large amounts of water overwhelmed streets, sewers, and local waterways in a short amount of time.

Just one inch of rain across the Milwaukee Metropolitan Sewerage District’s (MMSD) service area equals about 7.1 billion gallons of water. That is enough water to fill Fiserv Forum to the roof about 10 times.

When rain falls on streets, rooftops, and parking lots, it quickly runs into storm drains, sewers, rivers, and lakes. Managing this water takes many tools working together across the region.

One of those tools is green infrastructure, which helps capture the first inch of rain where it falls and slows the amount of stormwater entering the sewer system.

Green roofs grow vegetation to absorb rain and improve a roof’s performance.
Tree leaves and branches intercept the rain, slowing it or holding it until it evaporates. Tree roots create tunnels in the soil that help water soak into the ground instead of running off into streets, sewer pipes, and rivers.
Porous pavement systems allow runoff to soak into the pavement surface and engineered stone layers.
Cisterns capture rain for use when it’s dry outside, and help prevent rain from becoming polluted stormwater runoff.
Bioswales are landscape features that collect polluted stormwater runoff, soak it into the ground, and filter out pollution.

How Green Infrastructure Slows Stormwater

One way MMSD helps reduce stormwater impacts is through green infrastructure, a type of nature-based solution.

Green infrastructure uses natural features such as soil, plants, and open space to slow rain, help it soak into the ground, and reduce the amount of water entering the sewer system at once.

It includes features such as rain gardens, trees, bioswales, green roofs, and restored wetlands. These features help capture rain where it falls, allowing it to soak in, be used by plants, or evaporate naturally instead of rushing into the sewer system.

By capturing the first inch of rain, green infrastructure helps reduce pressure on the sewer system, lowers the risk of basement backups, and helps keep rivers and lakes cleaner.

Where Green Infrastructure Can Make the Biggest Impact

Green infrastructure is not placed randomly. MMSD uses a combination of data, long-term experience, and community conditions to decide where it can have the greatest impact.

Over time, this approach has grown and improved as we’ve learned more about how storms affect different parts of the region.

Major flooding events in 2008, 2009, and 2010 showed how flooding is connected to pavement, limited tree canopy, urban heat, and pressure on the sewer system. These lessons helped shape MMSD’s Regional Green Infrastructure Plan in 2013, which guides investments in areas with the greatest need. Many of these areas are also communities that have experienced long-term underinvestment.

In 2023, MMSD began developing a new planning tool to strengthen how green infrastructure is prioritized across the region. The tool was launched at the end of 2025 and continues to evolve as we learn more. We are currently working to include lessons from the major storms in August 2025 and April 2026.

Today, MMSD brings together a wide range of information to identify priority areas, including:

Flooding patterns and past storm events
Areas with a high percentage of impervious surfaces
Sewer system performance and drainage conditions
Soil type and land characteristics
Tree canopy and urban heat impacts
Social and economic conditions, including income, employment, and educational attainment
Household and community characteristics, such as age, disability status, language access, and single-parent households
Housing and transportation factors, including housing density, crowding, vehicle access, and housing type
Access to green space, along with environmental and public health considerations, such as water and air quality

By combining this information, MMSD can identify where green infrastructure will provide the greatest benefits—not only for managing stormwater, but also for supporting healthier, safer, and more resilient communities.

Green Infrastructure Projects Across Milwaukee

Antrea Taylor of Milwaukee’s Lincoln Creek neighborhood, “I really had no prior knowledge of rain barrels or rain gardens before,” she said, “but Ethan (Clean Wisconsin) handed me a pamphlet, and I thought it sounded great.”

Building Neighborhood Resilience in the 30th Street Corridor

One example of this approach is MMSD’s work in Milwaukee’s 30th Street Corridor and Century City area.

In 2013, MMSD began partnering with the Northwest Side CDC, Clean Wisconsin, and the Century City Triangle Neighborhood Association to provide residents with practical solutions, such as rain barrels, rain gardens, and downspout disconnections.

These efforts focus on individual households, helping reduce runoff right where people live. But they also helped connect small changes at home to the larger flood management system in the neighborhood, including the 30th Street Flood Management basins.

This work helps people see how small changes at home fit into a much larger system designed to manage stormwater across the area.

Over time, this work builds awareness, strengthens relationships, and supports a shared approach to addressing flooding challenges. It continues to be a lasting partnership between MMSD and the community.

Green Schoolyards That Capture Stormwater

MMSD and the City of Milwaukee have committed to working with Milwaukee Public Schools (MPS) and Reflo on green schoolyards to manage stormwater, create environmental education opportunities, and generate healthier outdoor spaces for students and the surrounding community.

Since 2016, 26 green schoolyards in MPS have been completed, with an additional 23 projects in planning, design, and construction. In total, over 20,000 students have been engaged in redesigning their schoolyard.

In 2025, MMSD and MPS committed to a 3-year agreement to construct an additional 15 green schools.

Starms Early Childhood Center (ECC) is one of the many green schools that has been invested in the 30th St Corridor. In 2019, Starms had 12,200 square feet of impervious surface removed and installed green infrastructure capable of managing 32,730 gallons of stormwater per rain event. The permeable rubber play centerpiece replaced 80% of the asphalt and features Lake Michigan, connecting students to local geography.

"Starms ECC’s schoolyard redevelopment is the anchor of the community by providing a safe green space at the intersection of 27th and North Avenue. Our closest park is over a mile away. We encourage the community to use our grounds after school and on the weekends. We see our schoolyard as being the launching pad of learning for generations to come here at Frances Starms Early Childhood Center." Lisa Misky

Partnering with Communities to Build Green Infrastructure

MMSD provides green infrastructure design, construction, and vegetation establishment services to property owners through several funding programs, including the Fresh Coast Green Communities program, one of our two public-private partnership models. This public-private partnership model leverages funding to deliver projects while also creating opportunities for emerging businesses through mentorship and construction bidding.

The Fresh Coast Green Communities program delivers green infrastructure improvements for property owners across the service area. One recent project, the Kinship Food Pantry, is part of this portfolio and scored highly using our new green infrastructure prioritization tool due to a combination of environmental conditions, social and economic factors, and its location within the combined sewer service area.

Kinship provides food pantry services, mental health services, and workforce development programs, with a mission grounded in health, wellness, and sustainability. Kinship is planning a new building that will include green infrastructure. Kinship is adding a green roof, permeable pavement, and subsurface storage that will capture over 85,000 gallons of stormwater.

More Than 20 Years of Green Infrastructure Investment

St. Francis School District received an MMSD Green Luminary® award in 2024 for installing green infrastructure that captures 280,000 gallons of stormwater during each rainfall event.

MMSD has been working with green infrastructure for more than 20 years alongside municipalities, community organizations, schools, and regional partners to build stormwater solutions across the region.

Since the early 2000s, projects such as rain gardens, bioswales, permeable pavement, tree planting, and wetland restoration have helped create millions of gallons of stormwater capture capacity.

Across the region, more than 173.1 million gallons of green infrastructure have been built, with MMSD directly contributing 75.6 million gallons. Since 2004, more than $80 million has been invested in priority communities, resulting in over 30 million gallons of capture capacity in low-income or historically underinvested areas.

These investments are made possible through strong partnerships with cities like Milwaukee and other local governments, as well as additional public and private funding. Together, we focus on areas where the risk of flooding and social and environmental vulnerability are higher.

How Green Infrastructure Supports Flood Resilience

Green infrastructure helps us capture rain where it falls. By combining data, lived experience, and community input, MMSD and its partners can place green infrastructure where it will have the greatest impact, not only for stormwater but also for health, community well-being, and quality of life. Green Infrastructure is not the single solution to flooding, but it is one of the most visible ways we work with communities to build a more resilient region together.

Green infrastructure is one important part of a larger, integrated flood management system. It works alongside other efforts, such as larger flood management projects like the East and North Basin projects in the 30th Street Corridor, policies and standards such as Chapter 13, ongoing system maintenance, and land protection efforts like Greenseams, all of which help reduce the risk of flooding across the region. Together, these pieces work as a system to manage water across the watershed.

MMSD remains committed to continuing this work and investing in green infrastructure in the years ahead, working with partners to expand projects where they are needed most across the region. In the most recent three-year Strategic Plan, MMSD has set a goal to install 8 million gallons of green infrastructure capacity in 2026, with nearly 5 million gallons of that capacity to be installed within the City of Milwaukee.

How Residents Can Help Manage Water on Their Property with Green Infrastructure

Downspout Disconnection

During heavy rain, every downspout on your home can send 12 gallons of water a minute to the sewer system, which increases the risk of sewer water backing up into your basement and overflowing into our rivers and Lake Michigan. Disconnect your downspout and help keep excess water out of sanitary sewers and into your yard or a rain garden.

Install a Rain Barrel

Get FREE water by the barrel from your roof and use it when it’s dry outside to use in your landscape. Rain barrels help keep excess water out of the sewer system and help reduce water pollution.

Plant a Rain Garden

Rain gardens help reduce sewer overflows and water pollution by absorbing stormwater runoff from hard surfaces into the ground naturally. Learn how to plant a rain garden and help protect Lake Michigan.