SLAYTON – Murray County is seeking public comment regarding the replacement of outlet structures at Lime Lake and Lake Sarah. An informational hearing will take place Wednesday, January 20 at the 4-H Building on the Murray County Fairgrounds. The meeting for Lime Lake will be from 6 to 6:50 p.m., with the Lake Sarah meeting beginning at 7 p.m.
Because of COVID restrictions, routine public participation will be modified, with several options for comment. There is both an online and conference call participation option, and public comment can be made via mail or email to Parks Director Justin Hoffmann at firstname.lastname@example.org. There will be limited personal attendance, and those who wish to be there must RSVP to 507-836-1166 to make arrangements.
Murray County has hired Houston Engineering to complete design work for the proposed improvements. A rock arch rapids configuration for both dams is being planned.
Project information, the comment form, meeting contacts and more can be found online at murraycountymn.com.
According to DNR Area Hydrologist Tom Kresko, neither dam is in good condition, but the actions being planned are not about water clarity or fishing improvements. Kresko said it is unclear if the change would improve sport fishing, since both dams have some degree of passage under moderate flow conditions.
In the case of the Lime Lake Dam in Avoca, flow exceeds the capacity of the dam, which was built many years ago. “It is half the size it should be,” Kresko said. “Erosion is happening – scouring a hole.”
Rock arch rapids are designed to direct flow and energy to the center of the channel, and create step-like drops in the water level, with less than one foot drop per arch. The rock ramps and arches allow all fish, big or small, to migrate upstream during high, normal or low flows. The ramp and rapids provide spawning habitat that is often blocked or buried by dams.
Another benefit, Kresko said, is safety. The rock arch rapids eliminate the hydraulic roller effect which can pull a person down underneath the water and keep them there.
“It spreads the water out and keeps the flow going downstream,” he explained.
There are no plans for a drawdown on either lake, Kresko said. According to the meeting notices, water levels would be maintained, and there is no intention to change the runoff of the existing dam.
In Avoca, the Lime Lake Dam is in a county park, and a bridge goes over the creek so people can cross over to the other side. The dam project would also include replacement of the pedestrian bridge and potentially additional improvements to the park. How much gets done will, of course, depend on cost, although Kresko said there are funding opportunities when it comes to improving safety.
Murray County started a fund a couple of years ago for replacement of the dam in Avoca. That fund currently stands at $58,750.