The ongoing heat wave and drought has strained water systems statewide. The heat increases demand for water while the drought means less water is available.

“It's gone down some, hanging more closely to about 180 million gallons a day this week,” Ragan said. “We are still having some incidents of low pressure in some areas.”

In Oklahoma City's case, supply isn't the problem; there is plenty of water in the city's three lakes. Ragan said the issue is being able to treat enough water so that it is safe to drink.

This summer marked the first time in a decade the city called for mandatory rationing. The rationing rules put in place July 20 restrict watering with sprinklers and irrigation systems to every other day. Those with even addresses can water on even-numbered days and odd addresses on odd days.

Ragan said automated phone calls were made this week reminding residents about the rules.

“Typically when we ask for help, it doesn't last very long, so we thought we needed to remind people,” Ragan said.