A six-year journey is well underway at the Milwaukee County Grounds to help reduce the risk of destructive floods along the Menomonee River.

If you're new to the area, you may not realize that flooding in Milwaukee County in 1997, 1998, and 2000 caused about $96 million of damage to homes, businesses and neighborhoods.

Since 1973, flooding is blamed for the loss of four lives in the county.

There are numerous reasons why the Milwaukee Metropolitan Sewerage District (MMSD) is doing this project, some you cannot assign a dollar value. Just ask anyone who's lost decades of family pictures, heirlooms or everything they own to floodwater.

If you have questions or concerns during construction, please call: 

Flood Management on the County Grounds
This $99 million project captures and stores potential floodwater in one large basin that construction crews will dig on 91-acres of land. The actual basin will cover about 65 acres.

A large, underground tunnel that's 17 feet in diameter and about a half-mile long will channel excess water from Underwood Creek into the basin.

From there it will slowly release into the Menomonee River.

The basin will hold approximately 315 million gallons of water and may only be needed for storage a few times a year.

During extreme storms, the basin could fill in about four hours. If completely filled, it will take approximately four days to drain into the river.

As with all MMSD flood management projects, the County Grounds basin is designed to protect against the one-percent probability flood, commonly called the 100 year flood.

It's estimated that it would take 4.7 inches of rain over six hours in the Underwood Creek subwatershed to create a one-percent probability flood event.

Public access to the grounds during construction

For your own safety, we ask that you avoid entering any work zones. We're moving a tremendous amount of soil from the basin, about 2 million cubic yards. Most of it will be moved to the open space area.

This effort will take a couple of years. We ask for your patience.

Even if you're just walking outside the perimeter of the construction area, please wear brightly colored clothing so the drivers of dump trucks and large, earth-moving equipment can see you.

Orange construction fencing will be placed around the areas that people should stay away from.

However, always keep in mind, there are many blind spots on these big machines. It's not like driving a car.

Trucks and machinery will need to drive in and out of the construction areas.

 

Click to enlarge map of Milwaukee County Grounds Flood Management Project

Traffic on Swan Boulevard
To create the floodwater basin, MMSD is building a new bridge on Swan Boulevard that will cross over the basin.

For one year, about a quarter mile of Swan Boulevard will be limited to one lane in each direction near the intersection of Underwood Creek Parkway. A 25 mile per hour speed limit will be enforced in this area.

200-feet long and 100-feet wide, the bridge will accommodate four lanes of traffic.

$850,000 for new trees and plants

Creating this important flood management facility, unfortunately, requires that we cut down hundreds of trees on the county grounds. 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. MMSD is moving some trees from the former county nursery.

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.

Underwood Creek restoration

To make Underwood Creek safer for the public and friendlier for fish and aquatic life, MMSD is removing nearly one mile of concrete from the creek channel from Mayfair Road to the Menomonee River at Hansen Golf Course.

We're also rehabilitating the creek to restore a more natural flow pattern of pools and riffles.

The pools provide deeper and cooler water that help fish and aquatic life survive.

Creating a more natural flow helps slow water down. If you just removed concrete, you could actually make flooding worse.

Not all of the concrete is coming out of the nearly one mile stretch that's being rehabilitated.

About 45% of the channel will have concrete on the side slopes to protect bridges and storm sewers.

                                                                    Construction Schedule