rock lined creek

greater Milwaukee Flood management 

Greater Milwaukee Watersheds

Flooding and erosion of the watersheds in the Greater Milwaukee Area threaten public health and private property. Because watershed boundaries do not necessarily follow municipal boundaries, reducing the risk of flooding requires looking at the watershed as a whole, including the complete river system and its tributaries.

A watershed is land that channels rain and melting snow to a stream or river leading to a body of water. Milwaukee Metropolitan Sewerage District's (MMSD) authority to reduce the risk of flooding is in Wis. Stats., sec. 200.31(1).

Milwaukee Metropolitan Sewerage District is responsible for reducing the risk of flooding for two reasons:

  1. Managing flooding promotes efficient use of the sewerage system by reducing infiltration and inflow to sewerage pipes.
  2. A regional government is the most appropriate entity to address watershed issues that involve multiple municipalities.

View MMSD Flood Management Project Highlights.

What Watersheds Are Within MMSD's Service Area?

There are six watersheds within MMSD’s service area:

  • Kinnickinnic River
  • Menomonee River
  • Milwaukee River
  • Lake Michigan Drainage
  • Oak Creek
  • Root River

The planning process for the development of the updated Watercourse System Management Plan began in1998 with MMSD and local municipalities. Resulting in flood risk reduction alternatives for each of the six watersheds. The first stage, Phase I, of the planning process incorporated the results of past planning efforts such as the 1990 Watercourse System Plan developed by the Southeastern Wisconsin Regional Planning Commission (SEWRPC) as well as new technical information on land use, peak stormwater flows, estimated damages, and other hydrologic and hydraulic information.

As part of this planning process, meetings were held with stakeholders in each watershed to identify problems, and prioritize potential alternatives for flood management. Flood management work has included: rehabilitation and removal of concrete, sediment and flow-impeding objects, and widening floodplains.

MMSD and partners have invested hundreds of millions of dollars to reduce the risk of flooding in our area. At the same time, heavy downpours have caused hundreds of millions of dollars in property damage over the years and people have died due to flooding in our area.

  • Flooding in Thiensville

    Flooding in Thiensville

  • Flooding in Wauwatosa

    Flooding in Wauwatosa

  • Sinkhole in Milwaukee

    Sinkhole in Milwaukee

  • Water Knocks Down Basement Wall

    Water Knocks Down Basement Wall

  • 2010 Hart Park Flooding

    2010 Hart Park Flooding

  • 1998 Menomonee River Flooding

    1998 Menomonee River Flooding

  • Kinnickinnic River Rushing Concrete Channel

    Kinnickinnic River Rushing Concrete Channel

MMSD Flood Management Project Highlights

From Flood Control to Flood Management

As Milwaukee became increasingly urbanized, wetlands were replaced with impervious surfaces, such as streets, parking lots, and rooftops, which prevents rain and melting snow from naturally being absorbed back into the soil. The natural drainage system for the watershed was lost, leaving water with nowhere to go and making the area particularly prone to flooding.

In the 1950’s, 1960’s, and 1970’s, MMSD implemented numerous flood control and streambank stabilization projects for waterways within Milwaukee County. The projects completed up through the 1970’s predominantly focused on storm/flood water conveyance capacity. At the time, flooding streams, creeks, and rivers were viewed as a serious nuisance. Rarely were the waterways seen as valuable environmental resources and community assets worth protecting. During this time, MMSD’s flood control practices consisted primarily of straightening, deepening, and widening the various streams, creeks, and rivers within its jurisdictional area.

These waterway modifications were deemed as necessary to rapidly move additional storm and floodwater downstream. These waterway alterations consisted most often of lining the bottom of the waterway with concrete creating a concrete channel. This reduced the amount of friction, prevented erosion, and reduced the need for maintenance while moving the water quickly away from neighboring homes. This was the most common flood control techniques during this time, and many streams, creeks, and rivers in the Milwaukee region received this type of alteration.

The philosophy of flood control and accompanying engineering practices evolved into something better, not only having public safety foremost in mind but also long-lasting environmental and quality of life benefits connected with flood management projects. This prompted MMSD in 1996 to invest in an environmentally responsible watershed planning program, with the goal to manage current flooding problems while putting policies and programs in place to reduce future problems. This new program’s philosophy was shifted from the old paradigm of flood “control” to flood “management”.

concrete lined kinnickinnic river in Jackson Park

Concrete Lined Kinnickinnic River in Jackson Park.

This shift in philosophy recognized that severe weather and extreme rainfalls resulting in flooding could only be managed and not controlled. The watershed planning program also provided an opportunity to reverse some adverse flood relief techniques utilized in the past. It was recognized that previously concrete channelized waterways could be rehabilitated with proper planning to accommodate both flood flows and improves stream habitat and water quality. All these features collectively provide an attractive community asset that can also stimulate economic benefits and increase surrounding property values.

Additional Flood Risk Reduction Efforts

greenseams property


Greenseams® is an innovative flood management program that permanently protects key lands containing water-absorbing soils to prevent flooding.

farmers in field working

Working Soils®

The Working Soils® Program aims to permanently protect privately held working land in the Milwaukee River watershed floodplain. Healthy soils store rainwater, recharge groundwater, and reduce water pollution.

green roof on business

Green Infrastructure

Green infrastructure captures, absorbs or stores rain and melting snow, taking on numerous shapes and sizes from 55-gallon rain barrels to trees and porous pavers for parking lots, driveways and sidewalks. You can see green roofs on buildings or bioswales along city streets.