The Milwaukee Metropolitan Sewerage District (MMSD) is blending the best engineering and environmental practices with extensive public outreach to plan for and control flooding in the future.
Overwhelmed by back-to-back 100-year storms in 1997 and 1998 that damaged property, claimed two lives, and created a torrent of negative publicity, MMSD is engaged in a $300 million “conventional” flood control project, with a design year of 2020. For the decades after that, the district is taking an innovative approach called Greenseams. It involves the purchase and preservation of land that can naturally store and absorb floodwaters.
“Our goal is to protect lives and property, while keeping stormwater out of the sewer system,” says Kevin Shafer, executive director. “We want to implement flood management in an environmentally sensitive manner, while improving neighborhoods.”
The plan emerged after extensive public meetings and input, beginning right after the 1998 flood. The district formed a flood-control policy committee with stakeholders from organizations throughout the region. The committee prioritized projects based on potential threats to property and human life from another 100-year storm.
The ongoing year 2020 plan involves nearly 30 projects across the six watersheds in the district’s 420-square-mile service area (see table). These include:
• Eliminating concrete channels and naturalizing stream banks.
• Constructing multi-use flood-water storage basins
• “Shrinking” the flood plain
• Purchasing vulnerable structures and relocating residents
• Rehabilitating existing infrastructure.
Out with concrete
The flood management motto at Milwaukee may well be “remove as much concrete as you can.” MMSD had numerous concrete flood-control channels throughout the 28 communities it serves, many dating back 40 to 50 years.
“These channels actually exacerbated our flooding problems because they increased the velocity of the water passing through them, and they caused serious bank erosion in sensitive areas,” explains Shafer. They were also dangerous: The two fatalities during the 1998 flood involved youngsters caught in one of the channels.
The solution? Wherever possible, return these channels to a natural state. “We’ve removed about 90 percent of the concrete in our channels,” says Shafer. And in several neighborhoods, MMSD has actually been able to “shrink the flood plain” by widening and deepening the channel and maximizing the slope of its walls. In effect, the width of the channel becomes the width of the flood plain.
In other stream naturalization projects, removal of weirs and small dams has permitted aquatic life to thrive. Stream banks become more hospitable recreation areas when cleared of brush and trash and then re-vegetated.
The Lincoln Creek project is a good example. This 9-mile creek drains a 21-square-mile, densely populated urban watershed. The neighborhood reported more than 4,000 separate flooding problems along the creek between 1960 and 1997.
Beginning in 1998, crews removed the creek’s concrete lining and created a more natural, meandering waterway to keep the creek’s flow within its banks during heavy rainstorms. The reconstruction has shrunk the flood plain, moving it father away from some 2,025 homes and businesses.
Project designers created two detention basins (total capacity 80 million gallons) to prevent storm runoff from spilling over the creek banks. They also took measures to improve the attractiveness of the corridor; improve water quality; restore, stabilize and protect eroding banks; and provide a suitable habitat for fish, birds and other wildlife.
To help ensure ongoing success, MMSD worked with the Urban Open Space Foundation to create the Lincoln Creek Stewardship Council — responsible for promoting citizen involvement such as stream bank cleanups and invasive species removal.
Making room for water
Another major part of the 2020 flood-control plan calls for detention basins at key locations. Milwaukee’s approach is to create expansive areas that will contain and absorb flood-waters, while supporting recreation during dry weather. For example, in the community of Brown Deer, a school baseball field was modified to double as a detention basin. At another school, an existing pond was being likewise retrofitted.
Milwaukee’s largest detention pond project is known as County Grounds. It’s a 65-acre basin that crews are digging on 91 acres along the Menomonee River in suburban Wauwatosa. At 2.2 million cubic yards, it is one of the largest earth-moving projects in Wisconsin. The pond will store up to 315 million gallons. The cost is $84 million. An underground 17-foot-diameter, half-mile pipe will connect the basin to nearby Under-wood Creek.
To create the basin, the district had to remove hundreds of trees, and that understandably caused public concern. “Working with the Department of Natural Resources, Milwaukee County, and the public, we have developed an extensive habitat restoration plan that emphasizes replanting trees, shrubs and plants with native species,” says Shafer. “MMSD is moving some trees from the former county nursery. It will take time, but ultimately this will be a scenic area.”
Some 66 acres of trees will remain untouched where the DNR’s Forestry Education Center will be built on the border of the flood management basin.
Get out of the way
In some cases, residents and businesses have simply had to move out of the flood plain. Here again, Milwaukee has used public outreach to make sure the process is successful. The moves have been voluntary. Buildings have been valued based on non-flood-plain valuation, and MMSD has paid relocation costs.
In the $12 million Valley Park project, completed in 2001, a new levee and floodwall now protect about 130 homes. Some residents, however, had to be relocated. The district acquired 18 homes, replacing some within the neighborhood but outside the flood plain. MMSD worked with the residents to select an architect and collaborate with the contractor on home designs. The district also paid the construction costs.
“Not only did we get habitable buildings out of the flood plain,” says Shafer, “those that remained were able to be de-listed from flood insurance requirements.”
Greenseams for the future
In addition to the $300 million conventional flood management program now under way, the district is preparing for what could happen after 2020. “In the face of ongoing development throughout our district, we asked ourselves how we could mitigate flood damage in the future,” Shafer explains.
Through the Greenseams program, MMSD partners with communities, organizations, and land owners to acquire and maintain or restore the natural state of thousands of critical acres of hydric (water absorbent) soils and wetlands — forever.
The district has identified critical parcels of water-absorbing land and areas along stream corridors that connect the region’s public properties. In 2003, the district began purchasing certain parcels and turning them over to communities or land trusts, which own and manage the land. The parcels are subject to a conservation easement held by MMSD that ensures the land will remain open and free of buildings or impermeable surfaces. Approved uses include hiking trails, bird watching, and other passive recreation.
In some cases, the district acquires wetlands and restores them to their natural hydrological state. To date, MMSD has acquired 1,300 acres and has identified a total of 7,000 acres of hydric soils. As individual parcels are added, contiguous areas (green seams) start to develop.
To handle negotiations with interested land owners, MMSD works with The Conservation Fund, a national organization that maintains an office in Milwaukee. Purchase prices are based on appraisals; funds come from the MMSD capital budget, as well as a number of grant programs, such as the Wisconsin DNR Stewardship Program and the Wisconsin Coastal Manage-ment Program.
Peg Kohring of The Conservation Fund works with 10 Midwestern states and applauds Milwaukee’s non-structural approach to flood control. “Every-one seems to be looking at structural methods to reduce flooding,” she says. “To have Milwaukee pilot green infrastructure in this way is very, very innovative. So often we hem in rivers with development and pavement, when really the land itself can give us nature’s benefits — and one of those benefits is flood reduction.”
The acquisition process is completely voluntary. “It’s not a condemnation procedure,” Shafer says. Shafer credits an intensive public education campaign, consisting of countless public meetings and extensive publicity, for the success of the program, and a growing public awareness about preserving green space and preventing flood damage.
“We’re finding that the public understands and appreciates the impact of open space in preventing flood damage,” he says. “The property owners we are dealing with have pride in their land and want to preserve it.”
Lawrence Hoerig farmed 80 acres on the Little Menomonee River just north of the Milwaukee County line for more than 50 years. Recently, he elected to sell 72 acres to the Green-seams program.
“I was ready to get out of farming, and it was nice to know that my land will always look the way it did when we farmed,” he says. “My kids were really proud; in fact my daughter said, ‘Dad, I’m so happy we won’t have houses built on our land.’”
Hoerig, 80, compliments The Conservation Fund organization as well. “They were very considerate and friendly — good people to deal with.”
In the end, Shafer believes public involvement is the key to successful flood control. “Even with the best engineering plans,” he says, “the public is not going to buy in unless you get out there in their neighborhoods. We’ve tried to make the watershed more of a focal point for the community — to bring the community back to the watershed.”
