Madison water utility considering citywide rationing strategies

In a memo posted Friday, water conservation officer Amy Deming recommends conservation strategies ranging from voluntary alternate-day watering schedules to a supply emergency that would suspend all non-essential uses — both indoors and outdoors — to ensure enough water for fire protection.

Each strategy would be triggered by demand levels to be determined by the water manager, who has the authority to impose voluntary or mandatory outdoor water use restrictions under local ordinances.

While the utility is primarily concerned about water supplies on the North and East sides, Deming recommends imposing citywide conservation strategies.

“This is because the entire Madison community can share the benefits of alternate day watering and reducing peak demand,” Deming wrote. “In addition, citywide implementation prepares and accustoms residents to the concept of alternate-day watering and Level 1-3 alerts in the event of a mechanical failure or other issue in their part of the city.”

The Water Utility Board is scheduled to discuss the recommendations Tuesday.

The utility shut down Well 15 on East Washington Avenue in 2019 after tests showed elevated levels of PFAS, likely the result of groundwater contamination from the nearby airport.

The utility board is evaluating the feasibility of a $670,000 treatment system that would cost $136,000 to $300,000 per year depending on the level of PFAS contamination allowed.

According to a memo from water supply manager Joe DeMorett, the utility can meet demand under most circumstances with other wells that supply the North and East sides, but a prolonged stretch of hot, dry weather like the summer of 2012 would tax the system.

That could force the utility to fill reservoirs during daytime hours when electricity is more expensive. If hot and dry weather persists, the utility says it would become impossible to keep the reservoirs filled even with wells pumping round the clock, DeMorett said.

A simulation conducted for the utility’s 2019 Master Plan update found it could not supply adequate pressure for fire protection with one or more wells out of service, even for a short period of time.

With fewer industrial customers, an ongoing shift to multifamily housing and high-efficiency appliances, Madison’s water use declined in 2020 for the sixth straight year to the lowest level since 1966.

According to DeMorett’s memo, demand reduction would only be required if one or more wells are down for an extended period, if the utility cannot fill reservoirs overnight or if demand reaches levels last seen in 2016 for days at a time.

Dane County is currently experiencing moderate drought conditions, though the National Oceanic and Atmospheric Administration’s Climate Prediction Center says there’s a 50-50 chance Wisconsin will see normal precipitation levels over the next three months.