Public Works Board recommends projects for Bridge St. structure, millpond that could cost $1.6 million
Plans to repair the west abutment of Grafton’s Bridge Street dam and dredge the adjoining millpond — projects that could cost nearly $1.6 million — received the backing of village’s Public Works Board on Monday.
The recommendations came after members reviewed options for both projects prepared in a Bonestroo engineering study, including abutment upgrades to meet state flood-control requirements.
The upgrade options include replacing a masonry wall, raising the riverwalk and reconfiguring the public overlook area; installing gates to provide flood control and dewater the reservoir for dredging and dam inspection; and enlarging the weir for flood control and to create additional recreational activities.
The cost of abutment work may be defrayed by a Department of Natural Resources grant program that could give the village as much as $400,000 through a matching-fund agreement.
However, the grant would not cover dredging costs.
Village Engineer Dave Murphy recommended installing a gate, 20 feet long by 6 feet deep, that would allow the reservoir to be drawn down by 4 feet, along with replacing the masonry wall and raising the riverwalk. The total cost of those improvements is estimated at $420,000.
However, board members agreed to remove the gate from the upgrade work, instead recommending the possible use of a coffer, or smaller temporary, dam to lower the reservoir. Without the gate, the cost would be pared to $170,000.
“We don’t need a gate to dredge or comply with NR333 (the state law regulating dams),” said board member Lisa Uribe Harbeck, a village trustee. “We can save money on this.”
Board members and several residents in attendance also voiced concern about the cost of operating and maintaining a gate.
Although dredging is not required, village officials have agreed to explore having that work done in selected areas to remove sediment to create a more scenic impoundment and improve water quality. Village Administrator Darrell Hofland recommended having three east-bank locations dredged — a 1,560-cubic-yard area just north of the Highway 60 bridge, a 1,314-cubic-yard area just south of the bridge and a 1,300-cubic-yard area where Ozaukee County wants to build a fish passage.
In addition to concurring with Hofland’s proposal, the board added two significantly larger dredging spots — a 24,400-cubic-yard area along the west bank north of Veterans Memorial Park and a 13,000-cubic-yard area south of River Island Park.
Those areas were suggested in late June at a public improvement meeting on abutment work and dredging.
A combination of dredging methods has been proposed. Murphy said mechanical removal of sediment, estimated to cost $13 per cubic yard, would be likely for east-bank areas, and hydraulic removal, costing $60 per cubic yard, would be used at the two largest sites.
If all five areas were dredged, that work would cost about $1.43 million, Hofland said. Combined with the abutment and riverwalk upgrades, all projects would total $1.59 million.
A matching grant from the DNR for the abutment work would lower the cost by $85,000, to $1.5 million, Hofland said.
The village is expected to pay for dam upgrades and dredging using revenue from the downtown tax incremental financing district rather than the general tax roll, a decision voters supported in an advisory referendum in April 2010.
The board voted 4-1 on its dredging recommendation, with only Trustee Susan Meinecke opposed. Meinecke questioned the need for dredging at a time when the village faces state-imposed budget constraints.
Still unknown is the fate of the fish passage, which would be built off the east abutment and defray the village’s share in the cost of east-abutment upgrades. Although the Department of Natural Resources made a preliminary decision to reject the project due to concerns about the spread of invasive species and a deadly fish virus, the agency’s final decision is not expected until later this summer.
If plans for the fish passage are dropped, the village may have to add as much as $150,000 for east-abutment work to the overall upgrade costs, Hofland said.
Although the gate is not included in the list of recommended upgrades, the board agreed that Bonestroo should prepare a grant application seeking as much as $420,000 in DNR funds.
That total would include a gate on the west abutment.
“This would cover a worse-case scenario,” Hofland said. “If the money is not needed, it would not be used.”
Bonestroo will be paid a maximum of $2,200 to prepare grant application documents. The application deadline is Sept. 15.
The Village Board is expected to act on the Public Works Board’s recommendations at its Monday, Aug. 15, meeting. However, the abutment work and dredging will remain on hold until
the fate of the fish passage and grant application are known, Hofland said.
The DNR is scheduled to announce grant recipients Nov. 15.
The village has until 2019 to ensure the dam meets state flood-control requirements.