By Mark Fischenich
The Free Press
NORTH MANKATO —
Attempts to keep a lid on spending had put the kibosh on well-drilling in North Mankato for more than five years, but the North Mankato City Council Monday night decided a new well could wait no longer.
The council gave preliminary approval for a $1.35 million well near Caswell Park to meet the growing demand for water projected over the next two decades. Even as the city's population has grown past 13,000, there's plenty of capacity in the existing four wells to meet demand -- even on the hottest summer days.
The potential problem comes if one of the city's two hilltop wells is out of service on that maximum demand day. By 2020, based on projections of growing population and water usage, the remaining well on the growing hilltop portion of the city couldn't meet the demand on such a day.
The city has the ability in an emergency to pump as much as 1,000 gallons of water per minute from two wells in the valley to the hilltop area. Even doing that, demand on the driest day of summer would exceed capacity before 2025 if an existing well is out of service, according to a feasibility report on the North Mankato water system.
The new well, with capacity to provide 1,100 gallons per minute, will keep the hilltop area supplied on a maximum demand day to nearly 2030 -- even if a hilltop well is down and even if water isn't transferred from the valley.
Councilwoman Diane Norland supported the addition of the new well, but she warned residents that she sees water-use restrictions in the near future if the ongoing drought continues.
"If things don't change much, we're going to have to do lawn-watering bans," Norland said. "We'll just have to."
City Engineer Brian Malm said he supports water conservation, but the need for a ban won't come from a deficiency in the system's capacity -- at least not for a while and not if the new well is added. The projections for maximum demand take into account widespread use of lawn sprinklers on a hot summer day.
"That's what causes your max day use," Malm said.
A November report by the Minnesota Department of Natural Resources found that the Mt. Simon aquifer, which the new well would tap, is possibly being depleted at a rate faster than it is being recharged. A network of observation wells were drilled to allow for closer monitoring of the aquifer.
Malm said the potential drop in the water level in the aquifer shouldn't be a concern for the 845-foot-deep well being planned.
"That's something we'll take into account with the design," he said.
If given final approval by the council later this spring, drilling of the new well could begin by June. That portion of the project, costing an estimated $755,000, will be followed in 2014 with construction of a building to house the pumping and monitoring equipment. The additional water capacity should be available by the fall of 2014.