Comments regarding possible environmental and other impacts related to the planned Silver Lake dredging and dam modification are being collected through March 11.
“This is just a fact finding,” Matt Crawford, project development manager for Rochester Public Works, said of an Environmental Assessment Worksheet that was recently completed. “That’s what the EAW is for. It doesn’t mean anything is certain.”
A link to the 59-page document providing information about the Silver Lake project and its potential environmental impacts is posted on the city’s project website at tinyurl.com/3ujrzfcf.
The worksheet provides information about the project and potential environmental impacts gathered during initial planning efforts. Topics covered in the document include water resources, geology, historic properties, air, noise, wildlife and plant communities.
The overall project is expected to include a northern trail extension and pedestrian bridge, but Crawford said the worksheet only covers the dredging and changes to the dam, since they will have the greatest environmental impact.
“The other two parts occur in the same work zone but don’t have any additional impact,” he said.
The entire project is expected to cost nearly $13.3 million, but planning continues and state permits will not be sought until work is ready to start.
The dredging is slated to begin in the summer of 2022, taking approximately six months.
The worksheet outlines the process for lowering the water level ahead of the dredging. Once the water is as low as it can go with the dam in place, the plan is to remove the dam and create “rock riffles,” which are designed to mimic natural pools that would collect water to help control flooding downstream.
Installation of the riffles is expected to take three to six months, with work occurring while the dredging is underway.
In all, Crawford said the lake will be at the low level for nine to 12 months.
During that period, he said city staff is also hoping to install footings for the planned pedestrian bridge. While some of the footings could be installed later, he said the low water level will provide an ideal time to place the middle footings.
“We could put some footings in now for the bridge in the future,” he said, adding that final work on the planned trail extension on the north side of Silver Lake could also be completed at a later date, if needed.
The bridge and trail extension is expected to cost approximately $4 million combined, while the dredging is expected to cost nearly $5.2 million and the changes to the dam are estimated at nearly $4.1 million.
The city has funds earmarked for the dredging effort, but is looking to state and other support to help pay for the rest of the project as planning and design efforts continue.
Crawford said the ongoing review process will help inform future design efforts, since agencies and local residents can review the information and register official comments on the project, which could raise concerns not yet addressed.
“It cuts down on issues later on,” he said.
Once the comments are gathered, Crawford said city staff will address each one and post the responses on the project’s website before going to the Rochester City Council to propose the next step in the project.