South wall of Estabrook Park dam is first to fall
Wall expected to be demolished this week; main dam next up
The south wall of the aging and deteriorated Estabrook Park dam on the Milwaukee River is being knocked down and trucked away.
One excavator equipped with a hydraulic hammer is pounding the serpentine concrete and limestone wall, known as a fixed crest spillway, that extends from the south bank of the river to an island at midstream.
The concrete outer shell covering the stone was removed first, then the heavy equipment went to work on the stacked limestone blocks.
All of the rubble will be crushed and recycled for local road projects, said Jeremy Triebenbach, senior project manager with the Milwaukee Metropolitan Sewerage District.
Demolition is exposing metal bars that had been used to stabilize the inside of the south wall.
Those bars will be cut off below the limestone surface of the riverbed to prevent injury to recreational users of the free-flowing river, Triebenbach said.
In March, the contractor dug out more than 200 tons of sand and muck from the riverbed immediately upstream of a curved section of the south wall in preparation for this week’s demolition, he said.
Tests confirmed the sediment contained such low levels of pollutants that it was non-hazardous, and the load was disposed of at a local landfill.
Removal of the south wall will be completed this week, Triebenbach said. After that, the contractor will shift to the main dam with floodgates north of the island.
MMSD’s commission in December awarded an $844,421 dam removal contract to Terra Engineering & Construction Corp. The company also will remove a series of pyramid-shaped ice barriers upstream of the dam section and a control building on the north bank of the river, under the contract.
All major demolition is scheduled to be done by May 1.
Floodgates on the 1937-era dam have not operated since 2008. The state Department of Natural Resources that year ordered then-owner Milwaukee County to open the gates after inspections found numerous safety problems and confirmed the need for extensive repairs.
A shallow upstream impoundment was drained at that time.
In 2009, the DNR ordered the county to remove or repair the dam. Milwaukee Riverkeeper, an environmental advocacy organization, sued the county two years later for failure to operate and maintain the dam in good working condition.
A Milwaukee County circuit court judge in 2012 declared the dam a public nuisance.
After several more years of inaction by the county, the Milwaukee Common Council in November 2016 rezoned county property on the north side of the dam as non-park land. Milwaukee County Executive Chris Abele then sold the parcel for $1 to MMSD for the purpose of demolishing the dam structures.
All property will be returned to the county for park use after dam removal and shoreline restoration is completed this year.