Rapid snowmelt could spell flooding
By ELISA SAND, Staff Reporter
Snow is starting to melt this week as the sun starts shining and temperatures start climbing. Looking at the extended forecast, temperatures are expected to reach the 50s by Thursday, 60s by Friday and 70s this weekend. But, a rapid warmup means a higher likelihood for flooding. Lake County Emergency Management Director Don Thomson said Wednesday (today) that the highest potential for flooding will occur Saturday evening and into Sunday as temperatures hit the 60s and 70s.|
"It will start slow, but by late afternoon/evening we will see a lot of water coming from the north," Thomson said, referring to snowmelt that should occur on Saturday.
Not all snowmelt in the county will come through Madison's waterways, however. Snowmelt occurring on the east side of US-81 (Rutland, Nunda and Wentworth) will stay in Battle Creek and head northeast toward Brookings. Water east of the Vermillion Hills goes to Buffalo Creek and through Chester. Water that reaches Madison typically comes from the Ramona area.
"That will all head this direction," Thomson said.
High water flow not only means an increased potential for water flowing over the surface of area roads, but it could lead to the deterioration of the base of the road, which is often referred to as undermining.
Thomson said that at this point, the frost is out of the ground and gravel roads are saturated.
"If we get moving water, it will start undermining roads here," Thomson said.
A sign of undermining is potholes and sinkholes that appear on the roads, he said.
In response to these conditions, Lake County Commissioners approved a motion Wednesday that extends the seasonal weight restrictions beyond May 1. Highway Superintendent Scott Mathison said the county will evaluate the roads from week to week to determine when the weight limits will be lifted.
Those traveling on gravel roads are asked to use caution and not to cross areas where water flows over the roads.
Thomson said the April snowstorms have brought the equivalent of about 5 1/2 inches of rain to the area and is now beginning to melt.
Residents should find an alternative route if they come across an area where water is crossing the road, and they should call Lake County's 911 Communications Center (256-7620) to contact authorities to block the roads.
Thomson said he is most concerned about water on township roads, but there are some county roads of concern as well. Roads with the most trouble are those where past flooding has occurred.
Madison residents should also make sure their sump pumps are functioning and pumping outside and not into the city's sewer system. City residents are required to pump directly outside beginning April 1. Thomson said pumping into the city's sewer system will overload the system.
Thomson said one factor that isn't of high concern this spring is blocked culverts. One issue that typically occurs each spring is ice blocking the flow of water through culverts, but Thomson said culverts are open by now.
"There should be minimal issues with ice jams," he said.
The issue is how much runoff will occur and how fast the water will come through the system.
Thomson said the water level at Lake Herman is rising and currently flowing through the spillway, but there's still quite a bit of capacity.
"Right now, the lakes should be able to handle all the water coming down," Thomson said, prefacing that comment by saying substantial rain could make a difference.
Anyone in need of sandbags can obtain them from the City Shop and County Highway Shop during regular business hours or at Ace Hardware.