The Sacramento Bee reported Thursday that the San Juan Water District board of directors approved the move this week.
The district serves more than 265,000 people in the Sacramento suburbs, including the communities of Citrus Heights, Orangevale and Folsom.
Most of its water comes from Folsom Reservoir, which the newspaper says has shrunk perilously low amid one of the driest winters in California history.
District General Manager Shauna Lorance says the call for conservation is not mandatory, but it could become so next month if the area doesn't get rain soon.
The district also is extending a request for a 20 percent cut in all water use that has been in place for months.
Mandatory statewide water conservation rules have ended in California. But Sacramento-area users conserved 22 percent in June, compared to June 2013.
California and federal agencies say a new strategy is needed to save the endangered Delta smelt.
California is in the fifth consecutive year of drought, but state water managers ended mandatory conservation rules. Local water suppliers now determine conservation rates, and some have low or no targets. A water expert says that's 'shortsighted.'
California is in the fifth consecutive year of drought. Although mandatory statewide water conservation is over, the State Water Resources Control Board says water conservation remains a "top priority."
The California Water Resources Control Board Wednesday says Californians cut water use by 28 percent in the final month of mandatory statewide conservation.