Recent rainfall draws concerns about pollution, invasive weeds in Minnesota

(KMSP) - Monday kicked off a wet and dreary week – and the rain isn't expected to stop anytime soon. 

The news is especially troublesome for Normandale Lake, which was recently drained to get rid of invasive weeds. 

Just a few weeks ago, Normandale Lake in Bloomington was drained dry to begin the process of killing off an invasive weed.

“We’re doing this to save the lake,” said Steve Gurney, a water resource specialist. “We had it drawn down to where we wanted, and then it started raining again so it’s filled back up and it’s kind of held there.”

All 116 acres filled up with more than four feet of rainwater, and more is on the way.

“Three days of rain is not going to be good for us,” Gurney said.

Crews are now forced to wait.

“We have until freezing temperatures to get things drawn down… what’s really going to be key is if we have everything drawn down at that point in time, then the bottom can freeze and we can kill off the curly leaf pondweed,” he said.

Meanwhile, in Washington County, state environmental specialists are keeping a close eye on the St. Croix River.

“With increased rain, we do kind of concern ourselves with increased sediment and pollution loading to the river itself,” said Eric Alms with the Minnesota Department of Pollution.

Sediment, which is a mixture of clay particles, silt and sand have spilled into the water. Experts say that rain can lead to more pollution, which in turn can threaten the habitat.

“So from the prospective of increased rains, that water has to go somewhere, and typically that can go in storm water ponds or wetlands, but it can also end up tributaries and that increased water can cause all sorts of different issues,” Alms said.

In Bloomington, it's causing delays.

“Mother nature doesn’t pay attention to what I say, but if she would, we could hold off on rain for a while,” Gurney said.