The Sauk River Watershed District has started the final repairs to the outlet culvert on its Judicial Ditch 2 sediment pond project near Osakis.
Blackstone Contracting LLC mobilized its equipment into the site last weekend and has begun enclosing the culvert work area with large sand bags.
A silt curtain has also been placed downstream of the work area as an extra measure, to capture any sediments that might be generated during construction, according to Jon Roeschlein, the district’s ditch and permit coordinator.
“Several other erosion control measures are planned and should control all sediments generated by the work,” Roeschlein said.
After the ponds were excavated in 2019 and during the refilling process, the outlet pipe eroded from water in the ditch that flowed backwards into the pond. This caused the pipe to drop in elevation and left the area in disrepair, Roeschlein said.
Because of high water, the district decided to wait for water levels to drop some before attempting the repair in an effort to reduce costs, Roeschlein said. Water levels dropped in summer of 2020 so the process to repair the outlet was initiated.
The existing 48-inch metal pipe is being replaced with a 48-inch cement pipe. Fish barriers are being installed on the outlet pipe as well as the inlet pipe on the primary pond. Mike’s Welding of Osakis is manufacturing the barriers.
“The barriers will keep rough fish like carp out of the ponds, reducing the re suspension of sediments,” Roeschlein said. “This will allow the ponds to function even better than they were without the fish barriers.”
In winter of 2019, there was 17,000 cubic yards of sediment removed from the pond system, the district said. This is equivalent to about 1,700 average sized dump trucks of dirt – sediment and nutrients that did not make it to Lake Osakis, according to Roeschlein.
Once this repair is complete, the ponds will again work as designed, to reduce sediment and nutrient loading to Lake Osakis, the district said.
Any questions or concerns about the project can be directed to Roeschlein at 320-352-2231 or via email at email@example.com.