Remove or Replace: Holly Mulls Over Future of Millpond Dam, Public Meeting May 27
(Crystal A. Proxmire, May 23, 2025)
Holly, MI – The Village of Holly has created a committee to explore potential solutions to problems with the Millpond Dam which the state says either needs to be replaced or removed.
The Millpond Dam, also known as the Holly Dam, was built in 1840, making it one of the oldest in Oakland County. Back then the dam had the purpose of fueling a grist mill at the site. At some point the dam was converted to provide hydroelectric power, and then that operation ceased.
These days the purpose is aesthetic, with the dam supporting Stiff’s Mill Pond which is used for fishing and for the enjoyment of about 20 homes that surround it. At normal levels the pond is about 25 acres. A small area of grass along Broad Street provides space for public fishing. Across the street another outlet connects overflow with the Shiawassee River, which is a popular spot for kayaking. There is also a spillway that formerly housed the Waterworks building. In 2017 Village Council voted to remove the building due to unsafe conditions.
However, according to the State, the Millpond dam has not been well-maintained through the decades, and in 2017 it was rated a “Significant hazard”, meaning that should the dam fail loss of life would not be likely, but it would likely cause economic loss and environmental damage. The dam has a concrete spillway structure as well as earthen embankments.
The dam in owned by the Village, but is regulated by Michigan Department of Environment, Great Lakes and Energy (EGLE). EGLE has notified the Village that they need to draw down the water level for safety reasons, and that level cannot be raised until structural issues are addressed.
According to a report done by ROWE Professional Services earlier this year, the left embankment of the dam is non-compliant and would need to be re-done to meet state safety standards. There are issues both with the size of the embankment and materials used. The report also expressed that forthcoming state standards need to be taken into consideration.
“Because Holly Dam is assigned a Significant hazard potential classification (rather than a Low hazard potential classification), these pending regulatory changes will significantly increase compared to the current flood. Since the existing spillway is deteriorated and cannot pass the current design flood with adequate freeboard, we anticipate an entirely new spillway will need to be constructed to comply with Part 315 once the proposed changes are adopted,” the report said. “EGLE suggested during our meeting that the Village might want to consider removal of the dam or reconstruction of the dam instead of addressing on the deficiencies of the left embankment of the diversion dam.”
Rowe agreed with the state’s recommendation of a draw down of the pond level until either repairs or replacement is made. They estimate that any option – repairing the dam, replacing the dam, or removing the damn – would take three to four years to complete. If the dam is removed, the pond would cease to exist.
A similar dam removal took place in Davisburg over the past couple of years. When the dam was removed the pond was eliminated and the river returned to its natural course. Native plants are now filling in the space that was once the bottom of the pond.
Since the 2017 inspection the Village has done tree and brush removal, “However, nothing has been done to address deficiencies associated with the principal spillway,” according to the report. “In addition, grading performed on the left embankment of the diversion dam in 2021, exacerbated concerns over this portion of the dam since clay fill was place on the downstream portion of the embankment. Efforts to address deficiencies on the left embankment were completed without obtaining a permit, which resulted in a Violation Notice being issued by EGLE.” The report states clay fill should generally not be placed on the downstream side of a dam embankment because it lacks permeability.
Because repairs would not bring the dam up to state standards, there are two options: replace the dam or remove it.
According to the ROWE report, “Removal of the dam would generally involve permanently lowering the river to its original level throughout he reach within the impoundment area of the dam. This would include the removal of the spillway and at least portions of the embankments so that water is no longer impounded, meaning there would not longer be a pond. A dam removal project would eliminate the need for a dam replacement project, with the periodic dam inspections, routine dam maintenance, and intermittent dam repairs.”
The cost of removal would vary based on the amount of sediment involved, which is not currently known. “We are aware of dam removal projects that have ranged in cost from a few hundred thousand dollars where there was relatively little sediment that was present, to dam removal projects of a similar size that cost over 10 times as much because of the amount of sediment present and limitations as to where the sediment could be placed on site,” the report states.
Replacing the dam could cost between $2,000,000 and $3,000,000.
Rowe recommends removal of the dam due to long term costs of repair and maintenance. They also noted that if the dam were to remain, “it would be prudent for the property owners that benefit from the dam and associated pond to bear these costs.”
Mechanisms for charging the homeowners could include establishing an Inland Lake Level under Part 307 of the Natural Resources and Environmental Protection Act, 1994 PA 451 which would allow Oakland County Water Resources to collect funds from property owners to pay for the reconstruction of the dam as well as inspections, maintenance, and repairs.
The State is requiring a four foot draw down by June 3. “If we refuse to do what they want they would hire contractors and sue us,” said DPW Director Brian Klaassen. A four foot draw down would reduce the depth, and create areas of exposed land of 30-40 feet from the north shore, Klaassen said.
Village Council voted unanimously to create a committee to study options for the dam. They will be opening up the opportunity for residents to apply. The committee will provide “research and recommendations to council as far as next steps,” said Village Manager Tim Price. Price told Council “we don’t have the funds to do any removal or replacement at this time.” He added that another possibility might be to ask Oakland County to take over management of the dam.
Klaazzen told Council he considers EGLE to be forcing an unfunded mandate on the Village, and that the dam is not as bad as the state says. “We’ve had large rains and it’s made It over the top of the spillway, but it’s not made it to the road,” he said.
EGLE has agreed to come out for a community discussion which will take place on May 27, 2025 at Village Council Chamber, 504 ½ East Maple Road at 6pm. The discussion will feature Rowe Engineering, SME, and EGLE.
NOTE: This story has been updated to include a photo of the main dam.
