As worries of a prolonged drought continue throughout the region, Petaluma City Council members on Monday will meet to discuss water conservation measures for residents of Sonoma County's second largest city.

Public Works Director Dan St. John will explain the current status of water supplies and will likely recommend a voluntary water-saving plan to potentially stave off mandatory measures if dry conditions persist.

The special meeting begins at 6 p.m. Monday at City Hall, 11 English St. The council isn't scheduled to take any formal action.

Mendocino County supervisors declared a drought emergency last week, and the city of Willits, which has its own reservoirs, plans to impose mandatory water reductions on its residents soon.

Lake Mendocino, a primary source of drinking water in the North Coast that also provides water to the Russian River water supply system, is critically low after a year of record low rainfall. Last year was a record dry year on the North Coast, with just 7.67 inches falling in the upper reaches of the Russian River.

Only 7.8 inches of rain fell in the Ukiah basin in 2013, compared to an average 33 inches; in the Santa Rosa basin, 5.7 inches of rain fell, compared with the average 32.5 inches.

Cloverdale, which relies entirely on wells recharged by the Russian River, could be especially hard hit by the drop in river flows. It is expected to adopt mandatory water conservation measures this month.

Throughout Sonoma County, officials are planning an aggressive wintertime conservation campaign and already are urging residents to limit water usage.

It's in that context that St. John is expected to urge Petaluma city leaders to participate in a regional "Drought On -#8211; Water Off" water conservation campaign, in which Sonoma and Marin County agencies promote water-saving measures including no outdoor irrigation during winter.

Other voluntary efforts to reduce water consumption likely will include cutting back on car washing, discouraging spraying of driveways and inspecting sprinkler systems for leaks. Indoors, officials recommend using low-flow shower heads and toilets, running dishwashers and clothes washers with full loads only, fixing faucet leaks and turning off faucets when brushing teeth, shaving or lathering hands.

The first stage of the water-shortage contingency plan, St. John said, is a 15 percent voluntary citywide reduction in water use. That could be accomplished by public education campaigns about simple measures: shutting off hose nozzles, not washing down pavement.

If "moderate" measures are needed, stage two kicks in, which would include mandatory 25 percent use reductions such as setting irrigation times. More severe measures could follow.

Petaluma buys most of its water from the Sonoma County Water Agency, but does have nine city wells that could be relied on to provide local water if needed.

The city will continue to increase its use of recycled wastewater, St. John said. In the past three years, the city has almost tripled its use of treated wastewater instead of potable water for irrigation.

Petaluma water officials will conduct a free water review and offer savings suggestions for residents. Call 778-4507.

You can reach Staff Writer Lori A. Carter at 762-7297 or