Des Moines water utility pushes customers to conserve as drought worsens

A challenging mixture of drought, heat and near-record demand for water has Des Moines Water Works asking customers to conserve voluntarily. 

Specifically, the utility on Monday asked metro residents to cut their lawn watering by 25%. It’s still OK to water gardens and to fill pools, etc.

If it doesn’t rain soon, there’s a good chance the utility will ask for a 50% voluntary cut in lawn watering, CEO Ted Corrigan said in an interview.

“We’re not asking people to stop watering their flowers or their gardens. We’re not asking them to shut down their pools or anything like that. We just want people to back off on the lawn watering,” Corrigan said.

This is only the second time in Corrigan’s 31 years at Water Works that the utility has had to ask customers to cut back voluntarily, and it has never rationed water in that time. The last voluntary cutback was in 2012.

The request covers Des Moines and cities that buy water from the utility, including West Des Moines, Johnston, Urbandale, Clive, Norwalk, Pleasant Hill and Ankeny.

Water Works pumped 88.6 million gallons on June 9, the highest since the peak of 96 million gallons in 2012.

The system has a design capacity of 110 million gallons a day, but 100 million gallons is effectively the limit, Corrigan said. When demand gets past 90 million gallons a day, as it would have Friday were it not for a modest rain in western Iowa, the system can risk eventual water pressure problems.

Records show irrigation can account for 40 million to 50 million gallons of demand in summer. In winter, demand averages 40 million gallons a day.

The Raccoon River, currently the main source of tap water, is running at 7.5% of its median flow for this time of year. The utility has used the Des Moines River less because of toxic algae problems, which have re-emerged a month early this year, Corrigan said.

The presence of the toxins has made the Des Moines River “essentially unusable” for drinking water at times, Corrigan has said. 

Water Works has taken the unusual step of getting permission from the Iowa Department of Natural Resources to dredge the Raccoon River near the water intake to improve flow to the treatment plant. Large metal gates, or flashboards, will be put on the low-head dam again to raise the water level, probably later this week, Corrigan said. 

The voluntary conservation plan calls for residents to avoid watering lawns or gardens on Mondays. Watering is not recommended from 10 a.m. to 5 p.m. on any day. The utility is asking property owners with even-numbered addresses to water on Sundays, Wednesdays and Fridays. Those with odd-numbered addresses should water on Tuesdays, Thursdays and Saturdays.

Water Works asks customers to avoid lawn-watering altogether if possible. If demand doesn’t get under control, the utility has a progression of other possible actions. The next one is a voluntary 50% cut in outdoor water use and asking cities and the county to shut off fountains and to close recreational facilities that use more water than they should. 

In extreme cases of water shortage, the utility could ban lawn watering. If customers didn’t comply within 48 hours after notice of a violation, water service could be cut off and a fee assessed. The utility also could implement water rationing, with a higher rate charged for exceeding limits.

In the past, Water Works hasn’t had to go beyond the voluntary programs.