For years, Hart Park in Wauwatosa, Wis., had been known primarily as the site of the Milwaukee area's busiest football stadium, with as many as five high schools calling the park home.

That's changing with the construction of the Milwaukee Metropolitan Sewerage District's (MMSD) $48-million Hart Park flood management project.

Hart Park, located along the Menomonee River, is being reconstructed and increased in size as part of the project to protect homes and businesses in Wauwatosa and Milwaukee from flooding.

The football stadium will still be there, but the Hart Park flood management project will have a much greater impact on the area than Friday and Saturday football games ever had.

Severe flooding in the Hart Park area in 1997 and 1998 caused millions of dollars in damage in Wauwatosa and Milwaukee, leading to MMSD's flood mitigation project.

The project includes the removal of 79 homes and businesses in the Menomonee River floodplain, lowering the floodplain between Hart Park and 63rd Street, constructing 3-foot to 6-foot high levees and a floodwall system, and adding drainage improvements.

The size of Hart Park will be increased from about 20 acres to approximately 50 acres when the project is completed.

The park, which is being lowered 1 foot to 3 feet, and the levee system will temporarily store floodwater that could damage nearby homes and businesses, or flow into the sewer system and cause basement backups and sewage overflows.

Hart Park will remain dry, except when the Menomonee River overflows its banks.

Super Excavators, Inc., Menomonee Falls, Wis., is the prime contractor on the Hart Park flood management project.

Work began in August of 2005, and is expected to be completed approximately two years from the time construction started.

Edgerton Contractors, Inc., Oak Creek, Wis., is doing all excavation for the levee system, including the construction of all levee earthen berms and excavation for levee walls. Four levee walls are being constructed by Edgerton for the job.

Edgerton is also doing river restoration on the north half of the river.

Levee walls are earth berms, except for levee walls near 72nd and State Street, which are being constructed of concrete.

"Everything else will be done with earth," said Dan Richter, project manager for Edgerton Contractors.

Edgerton's excavation at the site includes: 12,000 cubic yards of topsoil stripping and respread; 12,000 cubic yards of topsoil import; 62,000 cubic yards of site cut and fill; and 30,000 cubic yards of site cut and export.

Materials being excavated at the site are mostly sand and rock.

"We had some proctors taken on the material, and they're thinking it's about 30-percent clay, but basically it's sand and stone," Richter said.

Several contaminated areas, totaling approximately 3,800 tons, are at the site.

Soils that are heavily contaminated are being hauled to the Onyx landfill in Franklin, Wis., while other contaminated soils are being encased in the core of the levee berms.

Edgerton is using a three-crew system on the job.

One crew is doing demolition and removal of old building slabs and foundations and roads. Concrete pulled from the site is being crushed, and will be used as fill on the Marquette Interchange reconstruction.

Another Edgerton crew is doing river revetment work, while the third crew is doing cut and fill work at the site.

The contractor is using four backhoes on the job. There is also some scraper work, but that is limited.

"The minor cut and fill work is being done with scrapers. Everything else has to be done with conventional trucking because they have regulations on how much weight can be put on bridges going over the river," Richter said.

As part of the revetment work on the Menomonee River, a WPA wall that is part of the river is being removed and the grade cut along the river.

Working in the river and along its banks, a turbidity barrier is required.

However, the river bottom is so rough that a normal turbidity curtain didn't work because it didn't seal to the bottom of the river.

"Any disturbing you do to the river bottom or bank has to be secluded from the active stream, so we built a double jersey barrier to isolate our work zone from the active river," Richter said. "Plastic lines the jersey barriers. We fill that with stone, and the stone follows the contour of the river bottom and seals it."

The system has been accepted by the state Department of Natural Resources (DNR).

"It's a little bit more labor intensive, but it's doing the trick," Richter said.

Edgerton isn't allowed to construct a double jersey barrier longer than 500 feet in length at any one time.

"We've found keeping it to about a 200-foot to 300-foot work section at a time works well for us," Richter said.

A total of approximately 2,000 feet of double jersey barrier is being placed on the job by Edgerton as part of the river revetment.

Work in the Menomonee River includes the placement of armor rock to secure the base of the river and slope. Quarry stone is placed on the slope above the armor stone.

"On the river bottom we're using an armor rock, which is a ton to a ton-and-a-half stone for the base of it. On top of it is quarry stone, a specification stone that is more like a blocky stone. They're rectangular in shape, and they're placed with the backhoe and the thumb," Richter said.

Edgerton Contractors started work at the Hart Park flood management project in mid-August of 2005, and is expected to be finished with their portion of the job by May of this year.