Brentwood staff proposes voluntary alternate-day irrigation schedule to reduce summer water peaks

Brentwood water staff on Monday proposed a voluntary alternate-day irrigation schedule that would split customers into two groups—odd-address properties on Monday/Wednesday/Friday and even-address properties on Tuesday/Thursday/Saturday—to reduce large, short-term spikes in summer water demand.

Jeremiah, a water department staff member, told the commission, “we currently have about 10,000 connections to our water system… Out of those 10,000, we have about 5,000 that are irrigation related.” He described the demand swing that drives the proposal: “Our winter average day for last year… was 3,300,000 gallons a day. This past summer, for the month of August, we took an average day for that month [of] 10,200,000 gallons a day. The peak day during that August month was 12,300,000 gallons a day.”

The staff presentation emphasized that system capacity currently meets peak needs—Jeremiah said the system is rated at about 14 million gallons per day—but that designing and paying for long-term capital capacity sized to infrequent summer peaks increases costs. “When you start to try and design to those peak flows… you’re having to increase your pipe size, pumps bigger, footprints of stations are bigger,” he said.

Staff framed the program as voluntary and intended to “flatten the curve” of daily peaks rather than force conservation. “This is voluntary,” Jeremiah said. Staff plans to reach out first to homeowners associations and irrigation contractors to encourage schedule changes when systems are installed or serviced and to run a social-media education campaign so homeowners can change app-based controllers on their own systems.

Commissioners asked about enforcement and revenue impacts. Staff said the plan is not intended to reduce overall annual water use and that the city does not expect an annual revenue impact because customers would still use similar yearly volumes; the change targets timing of use. Staff also noted potential benefit to future wholesale-water contract negotiations by lowering the city’s future peak demand profile.

Jeremiah pointed to a local example: a mandatory program in the Farragut area outside Knoxville that reduced peak daily demand from roughly 60 million gallons to about 32 million gallons after a mandatory change in irrigation scheduling. Brentwood staff said their plan would begin as voluntary outreach with the potential to expand engagement over several years if it proves effective.

Next steps: staff will begin outreach to HOAs and major irrigation contractors, create a public information campaign, and return to the commission with any recommended ordinance or mandatory measures only if the voluntary approach does not reach desired results.