While Village of Grafton officials await word on the fate of a proposed fish passage for the Bridge Street dam, they continue to explore ways to upgrade the downtown landmark to meet state flood-control standards.The Public Works Board is scheduled on Monday, Aug. 8, to review cost options for improving the dam’s west abutment and dredging the Milwaukee River millpond.
Village Engineer Dave Murphy is expected to make a recommendation on proposed abutment upgrades, which range in estimated costs from at least $170,000 to replace a masonry wall with a concrete wall, raise the riverwalk and reconfigure the public overlook area to at least $550,000 to install gates to provide flood control and allow dewatering of the dam reservoir.
Upgrade options were presented by Bonestroo Inc. at a public informational meeting July 18. The engineering firm was hired by the village to prepare a list of possible improvements that would meet flood-control mandates by a state-imposed deadline of 2019.
During the meeting, Village Board members agreed to drop the most expensive upgrade option, which calls for enlarging the dam weir to help control flooding and create additional recreational activities such as canoeing and kayaking. Cost estimates for that work range from $1 million to $2 million.
With input from Murphy, the Public Works Board is also expected to make a recommendation on dredging, a process that would remove sediment to create a scenic impoundment, improve water quality and allow more recreational activities.
Based on the type of dredging and amount of dewatering required, clearing the sediment will cost $25,000 to $895,000, engineers estimated.
The village is expected to pay for dam upgrades using revenue from the downtown tax incremental financing district. The cost may be defrayed through a Department of Natural Resources grant program that would provide up to $400,000 in matching funds, but the money will not cover dredging.
Based on Murphy’s report, the Public Works Board is expected to make a recommendation to the Village Board for consideration as soon as Aug. 15, Village Administrator Darrell Hofland said.
Still undetermined is the village’s cost in upgrading the dam’s east abutment, where Ozaukee County is attempting to construct a federally funded fish passage.
Plans for the fish passage include repairs to the east abutment, but the DNR has made a preliminary decision to reject a permit for the $1.6 million project due to concerns about the possible spread of aquatic invasive species and a deadly fish virus.
After considering additional input from agencies, officials and residents, the DNR was expected to make a final decision on the county’s permit request by the end of July.
However, Hofland said DNR officials informed the village that the decision has been delayed. “It’s now expected sometime in August,” he said.
The village will not be able to finalize cost figures for abutment work and dredging until the fate of the fish passage is decided, Hofland said.