MARSHALL - It was a wet weekend complete with flood warnings on the Redwood River in Lyon County, but it didn't mean problems for the city of Marshall. Marshall wastewater treatment plant supervisor Bob VanMoer said Monday that although there was increased flow through the city's wastewater treatment plant over the weekend, there were no reports of sewer backups or flooding in town.
"Everything actually was running really smooth," VanMoer said. A variety of factors, including flood prevention measures, the fact that the soil was not already saturated, and short dry spells between rainstorms this spring, all helped stormwater drain away quickly.
According to precipitation measurements at the wastewater treatment plant, Marshall received a little less than 4 inches of rain this past week, most of it falling on Saturday.
On Sunday ,the National Weather Service in Sioux Falls, S.D., extended a flood warning in the area until 10 a.m. Monday. The Redwood River in Marshall was expected to crest just below a minor flood stage of 14 feet on Sunday, the NWS said. In Russell, the river crested at 15.21 feet on Saturday.
At this point, VanMoer said, it would take a heavier or sustained period of rain before Marshall would experience problems draining stormwater.
"A typical inch of rain is not going to be a concern," he said, although another week with three inches might be.
One area that is of concern for the city is sump pumps illegally hooked up to sanitary sewer lines. VanMoer said illegal sump hookups are the biggest issue facing Marshall's wastewater system right now. Pumping stormwater into the sanitary sewer, instead of letting the water flow into the storm sewer, can overload wastewater treatment systems and cause other problems.
During the weekend's rain, he said, "We saw a lot of stormwater coming in" to the wastewater treatment plant. "Unfortunately, we can't tell where it came from."
VanMoer said the city has been making progress on a house-to-house inspection of sump hookups to help fight the problem.
While Marshall wasn't much affected by the weekend rain, VanMoer said the city did extend help to the city of Pipestone. The two cities are part of MnWARN, the Minnesota Water/Wastewater Agency Response Network. MnWARN acts as a kind of mutual aid network for utilities emergencies. VanMoer said Marshall lent a six-inch portable pump to Pipestone on Sunday to help with a flooded lift station.