Kinnickinnic River

Kinnickinnic River Flood Management

A watershed is the land that channels rain and melting snow to a stream or river leading to a body of water.

The Kinnickinnic River Watershed, located in Milwaukee County, covers 25 square miles and empties directly into Lake Michigan. As a result of urbanization, nearly 50 percent of the surfaces within this watershed are impervious, such as streets, parking lots, and rooftops, which prevents rain and melting snow from naturally being absorbed back into the soil. Unfortunately, during storm events, water flows quickly off these surfaces and overwhelms the streams, which drastically increases the risk of flooding.

Problem

Decades-old solutions to address flooding in this area have proven to be ineffective and sometimes even dangerous. More than 660 homes and businesses are currently located within the 100-year floodplain and are at a high risk of flooding.

Solution

The Milwaukee Metropolitan Sewerage District (MMSD), along with other government and non-government agencies and organizations, are addressing the problem through The Kinnickinnic River Watershed Flood Management Plan. This multi-phase plan reduces the risk of flooding, improves water quality, and benefits communities through a number of improvements.

Kinnickinnic River Concrete Channels in Disrepair

In the past, the approach used to address flooding issues was to move water through the river systems as fast as possible. To accomplish this, areas of the Kinnickinnic River were “channelized” by lining them with concrete in the early 1960s.

More than 8 miles of waterways are either concrete lined or enclosed in culverts—tunnels that route a stream under roadways, railroad tracks, parking lots, structures, and parklands. These create a dangerous flow velocity of greater than 20-feet per second—faster than white water rapids—which have led to numerous drowning or near-drowning incidents throughout the years.

Most of the culverts and concrete-lined channels are in poor condition and reaching the end of their useful life.

There is also the public perception that the concrete-lined streams are actually open sewers or drainage ditches, rather than waterways that feed into Lake Michigan.

Wilson Park Creek Concrete Channel

Naturalized Kinnickinnic River in Pulaski Park

Restoring the Natural Flow

Restoring the natural flow of streams improves water quality. Water flowing through rock-lined streams restores natural turbulence, which was nearly eliminated by concrete. The churning motion aerates the water, which increases vital dissolved oxygen levels and slows the water flow. The turbulence and aeration allow organic materials and pollutants an opportunity to break down rather than being quickly transported downstream and deposited in estuaries, which contributes to “dead zones” at the river’s end.

Learn more in the MMSD Kinnickinnic River Watershed Flood Management Story Board.

Kinnickinnic River Watershed Flood Management Plan Highlighted Projects

• Pulaski Park Project. Remove 1,600 feet of concrete channel lining, improve two bridges, and enhance Milwaukee County Parks’ assets.
• Wilson Park Creek Reach 3 Project. Remove 2,100 feet of concrete channel lining from Wilson Park Creek, improve two bridges, and construct a new flood storage detention basin.
• Jackson Park Project. Remove more than 2,100 feet of concrete channel lining, reshape portions of the park to improve flood storage and enhance Milwaukee County Parks’ assets. 
• Kinnickinnic River between 6th and 16th Street Project. Remove 4,000 feet of concrete channel lining, expand channel from 50 to 200 feet, acquire and remove 83 homes, and improve five bridges.
• 43rd Street Ditch. Increase the flow capacity of culverts at 43^rd Street and Lincoln Avenue, remove 600ft of the concrete-lined channel and create an area to store floodwaters during heavy rains.

The section of the Kinnickinnic River between the I-94 bridge and 6th Street in Milwaukee, WI.  1,000 feet of concrete was removed to widen the channel and erected retaining walls in a landlocked area with steep slopes to prevent erosion. A nearby bike trail makes it easy for neighbors to enjoy the views and fish from the banks when the salmon and trout visit in spring and fall.

Change is here with more to come on Milwaukee's Kinnickinnic River since October 2012. Salmon are migrating further upstream this year with the completion of a flood management project by MMSD.