Silver Lake dredging and dam change expected to start in November

ROCHESTER — Work on dredging Silver Lake and replacing its dam is expected to start in November.

“Some of the things have not received final approval from the (Rochester City) Council and permits, but it is in the process phase,” Rochester Deputy Public Works Director Aaron Luckstein told a crowd of roughly 35 on Thursday during a presentation at Silver Lake Station.

If approved, the planned dredging project is expected to take five months, temporarily lowering the lake level to remove sediment from the main channel through the lake and offering time to start work on rock arch rapids and wave pools that will replace the existing dam.

Luckstein said proposed dredging could also remove sediment in other areas of the lake to improve recreational uses, but potential costs of the added work are still being calculated.

Early estimates put the cost of dredging at $5.2 million, using flood control funds. The new dam structure is estimated at $4 million, with some added costs for a trail connection.

“I’m anticipating it will be a little higher,” Luckstein said of the overall price, pointing to increased construction costs since original estimates were created.

Project Manager Matt Crawford said the work is expected to add a steady stream of trucks in and out of the southeast side of Silver Lake Park, as they carry the reclaimed sentiment from the lake to a city reservoir near the Kalmar Landfill, west of Rochester.

While the lake is lowered, Crawford said plans call for creating the new structure to hold water in the park, while allowing fish to travel upstream.

“You will have a lake,” he said. “It’s not going to drain, it’s not going to go anywhere, and it will function just as it does today.”

While early plans called for an 8-acre reduction in the lake footprint, Crawford said updated plans suggested by the Minnesota Department of Natural Resources push the new dam structures 200 feet east, reducing the lake impact.

Additionally, the DNR is supporting added dredging on the southern end of the lake to reclaim lake around a former peninsula, which had been filled in and used to store snow during past winters.

“The DNR was OK with returning as much of the natural peninsula as we could,” Crawford said, pointing out the work could add an acre to the lake’s size.

In the end, he said the overall lake size is expected to decrease by less than 5 acres, and some of the reclaimed area will be used to extend the city’s trail along the northern edge of the lake and connect it to the trail west of the Broadway Avenue bridge.

Area resident Greg Munson, who has been a vocal skeptic of the dam changes, said he continues to prefer no changes be made, but said he’s willing to see what emerges.

“I’m cautiously optimistic it will end up being a good thing,” he said, voicing support for the trail extension but questioning whether the overall work can still be completed for costs reported in earlier meetings.

Other area residents, however, said they’d like to see the work expanded.

Dale and Sandy Larsen said they’re disappointed a proposed pedestrian bridge on the west end of the park continues to remain a future project without a schedule.

Frequent bike riders, they voiced a desire to be able to ride around the lake without needing to share the Broadway bridge with vehicle traffic.

Rochester Parks and Forestry Division Head Mike Nigbur said while it’s unclear when the bridge could be built, plans call for installing the base of a center pier when the water is low between November and March. The base would reduce future costs and avoid the need to lower the water level in the future, if funding for the bridge emerges.

While the water is expected to return to normal levels after March, Crawford said it won’t be the end of related work around the lake.

The city plans to take advantage of the lower water level for sewer upgrades under the Zumbro River on the north side of Seventh Street Northeast, and work is expected to continue eastward after the water level rises, with construction occurring into next summer.

“You will have access to the park, but at times your route might change,” Crawford told the audience on Thursday.

Work on the rapids and fish passage will also continue as the water rises, eventually moving east and demolishing the existing dam.

When it’s all completed, along with retaining walls to protect the new north shore trail, Crawford said native plantings and other features are expected to provide a more natural view.

“When it’s done, it’s going to look like a natural system out there,” he said. “Yes, it’s man-made, but when we are done, after a few years, it will be hard to tell that it’s really man-made structures.”

As state and federal permits are being finalized, city staff is set to update the Rochester City Council on plans during a July 28 study session ahead of seeking final approvals for the project.

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