MANKATO — A long and continuing stretch of hot dry weather has Mankato’s water pumps laboring and city officials pleading with residents to follow restrictions on irrigation and other water use.
“With the eighth day of 90-degree weather, we’re working hard to encourage residents to conserve water,” City Manager Susan Arntz said Thursday morning.
The temperature in one municipal well house rose to 115 degrees Wednesday due to the long hours of operation by the pump and electrical switching equipment. The city has five wells operating to keep up with anticipated demand, but water supply was reduced for a time when one of the pumps failed.
“We’re monitoring that today and tomorrow and hope we won’t have to add further restrictions,” Arntz said.
The city pumped more than 8.2 million gallons Wednesday, nearly double the amount on May 9, when the high temperature was 63 degrees. Wednesday’s total was nearly 2 million gallons more than on June 9 of 2020 — a day that topped out at 83 degrees, said Kyle Hinrichs, the city’s water treatment superintendent.
The typical steep drop in water usage in the evening and overnight hours hasn’t been happening in recent days because irrigation systems are kicking in due to an extended period of below-average rainfall, said Public Works Director Jeff Johnson.
“We’ve been behind on rainwater for the last three months,” Johnson said.
The run of hot, sunny days in June has dried out whatever moisture remained in lawns and gardens in Mankato, and there’s no relief in the forecast by the National Weather Service. With the exception of Saturday, when the NWS is predicting a high of 88, every day for the next seven is supposed to top 90 degrees, including 95 on Sunday.
High temperatures first topped 90 degrees on June 3, and they haven’t stopped. If the NWS forecast holds, the run of 90-plus high temperatures is expected to reach 13 out of 14 days. Other than a 40% chance of rain on Friday, the forecast includes no precipitation.
With the official start of summer still 10 days away, city officials have been highlighting water conservation rules on its website and through its social media accounts.
The restrictions call for sprinklers and irrigation systems to be used only every other day and only between the hours of 6 p.m. and 11 a.m. People with a street address ending in an even number may water on even-numbered days, and those with odd-numbered house or business addresses can water on odd-numbered days.
An exception is made for new landscaping and sod or freshly seeded lawns, but only if property owners obtain the free city permit.
Gardens and flower beds can be watered with a hand-held hose at any time. There are also no restrictions on children’s water toys, although the water toys can only be used when people are present.
Violators will first get a warning but second and third offenses will bring $50 and $100 fines. Subsequent violations will result in a disconnection of irrigation meters or outdoor spigots.
People with irrigation systems can typically set them to only operate on odd-numbered or even-numbered days, something an irrigation contractor can help a property owner set if they don’t know how to do it themselves, Johnson said. And Hinrichs suggested it might be a good time to have a contractor come out for a system tune-up, particularly to check that irrigation heads aren’t leaking or otherwise performing poorly.
“A little money to hire somebody upfront can save a lot of money in the long run in operating your system,” Hinrichs said.
Conservation also means lower costs for the city water utility, fewer chemicals needed for water treatment and less consumption of water from the Mount Simon aquifer, which the city taps into when its shallow wells can’t meet demand. More than a million Minnesotans rely on that aquifer for all or some of their water.