As drought conditions persist in Petaluma and throughout the county, the city has so far avoided water restrictions, something city and county water agency officials attribute to voluntary efforts to reduce water use.

However, Petaluma leaders cautioned residents at a recent City Council meeting that conservation efforts must continue in the months to come.

The county water agency and Petaluma city staff have been monitoring the region's water supply on a weekly and even daily basis as an unusually dry spring led to an equally dry summer, said Dave Iribarne, Petaluma's water conservation coordinator.

Those dry conditions have led to historically low water levels at Lake Mendocino, an important water source for the Sonoma County Water Agency.

The lake is at the third lowest level it's been in recent history, said Petaluma's public works director Dan St. John.

Despite dry conditions, water levels at Lake Mendocino have not dropped below a critical level that would trigger mandatory water conservation measures.

That's at least in part because of water conservation efforts at the county and city level, said Brad Sherwood, a spokesman for the Sonoma county Water Agency.

"The good news is, we're seeing a positive response from" the cities, he said. "Over all, their use has declined, and they've done so by implementing various conservation programs."

Petaluma reduced its water use from 2,210 acre feet in July and August of 2012 to about 2,000 acre feet in July and August of 2013, Sherwood said.

"Our citizens are responding, we're doing well," said Iribarne, who outlined a number of measures Petaluma has taken to reduce its overall water use this year.

It has continued a popular Mulch Madness program where residents can convert their lawns from grass to mulch for free, and has expanded the program to large commercial businesses, converting about 25,000 square feet of grass to mulch at businesses this summer.

The city is also actively promoting the 20-gallon challenge, an initiative the Sonoma County Water Agency started earlier this summer. Participants volunteer to consume 20 gallons less water a day.

"Every drop of water that is saved we can keep in our reservoirs, which is crucial for our water supply not just for people, but so that we can release water for salmon in the fall," said Sherwood in an interview earlier this summer.

In addition to encouraging people to conserve, Petaluma has begun pumping recycled water through its "purple pipes" to irrigate numerous grounds around town this summer, including half of Prince Park, Wiseman Park, and at the Petaluma airport. Irrigation at Casa Grande High School is currently being converted to recycled water, a project expected to be completed this fall.

Using recycled water to irrigate these areas will result in a savings of about 48 million gallons of drinking water, according to a report by city staff.

Iribarne emphasized that, while all these steps have helped keep Petaluma from dropping below the "critical storage curve" that would trigger water restrictions, the city is not yet in the clear.

"We have until Oct. 28. to stay above that curve," he said. "It's looking good but we could have long periods of heat so we need to be careful and mindful."

(Contact Jamie Hansen at jamie.hansen@ar guscourier.com.)