By Tim Krohn
Free Press Staff Writer
— The cities of Mankato and North Mankato have been put on a “drought warning” by the state Department of Natural Resources.
The warning won’t trigger any emergency conservation requirements yet, but it’s an official warning that mandatory water reduction could come next spring if water levels aren’t restored over the winter and spring.
Princesa Hansen, a water use consultant with the DNR, said the widespread summer drought has left many communities in the same situation.
“We’ve been focusing on public water suppliers to ensure they have a sustainable and clean water supply,” Hansen said.
The drought warning means the two cities have to have a plan to meet a specific water usage rate for as long as the warning is in place. For Mankato and North Mankato, that usage rate is 50 percent above the average January usage rate.
January is used as a baseline because it’s usually the month with the lowest water use. Some communities that have more serious drought problems have a goal of 25 percent above their January usage, Hansen said.
“It’s easy to meet (the usage rate) now, but you have to plan how to meet them next spring if we haven’t had adequate rainfall and people start watering lawns,” Hansen said.
Mark Knoff, Mankato’s public works director, said that to stay at the 50-percent-above-January level next spring and summer would likely require an odd/even lawn-watering regimen. (Those on the odd side of the street allowed to water on odd days and vice versa.)
Things would get very serious if the DNR had to declare an “emergency phase” — something that’s two steps beyond the “warning” the cities are now under. At that point, Mankato and North Mankato would have to stay at their January usage level for as long as the emergency was in effect.
“If it got to that, there’d probably be no outside watering.” Knoff said.
Mankato and North Mankato get much of their water from wells in shallow aquifers underneath the river bed. Knoff said they drew more water than usual from wells in deep aquifers this summer as the drought affected the shallower aquifers.