The Washoe County Commission hears from the public at 2 p.m. Tuesday in the commission chambers at the county complex, 1001 E. Ninth St.
The initiative also would require a public vote before water could be imported from outside the county, adding that rule to the regional plan.
"We're just going to change the regional plan," said Bob Fulkerson, executive director of the Progressive Leadership Alliance of Nevada. "Our land-use plan is going to be based on a sustainable water supply."
Rosanna Coombes, Truckee Meadows Regional Planning Agency director, said she doesn't know whether citizens can use a ballot initiative to change the regional plan. Norm Azevedo, lawyer for the regional planning agency, could not be reached for comment.
The regional plan requires developers to obtain water rights to build projects but lists vast areas for eventual annexation. A regional water commission has been created to study importing water.
"We are a nameless coalition of citizens advocating for a united vision in which Washoe County's future growth is determined by its sustainable water resources," according to an email distributed by Fulkerson and others. "We are not 'no-growthers' but rather 'sustainable growthers.'"
In its petition, the group said the region has 175,000 acre-feet of water -- enough to support the current population of 415,000 and 185,000 more people.
In contrast, the regional plan has created growth areas where municipal services would be allowed for a total of 750,000 people over the next 20 years and future growth areas for 1.2 million people, according to the petition.
A population of 1.2 million would require a doubling of water resources and importing 208,000 acre-feet of water, according to the petition. The proponents fear current residents eventually would be required to subsidize the cost of imported water.
The Regional Water Planning Commission approved an update of the regional water management plan on Feb. 7 that includes a similar deficit. Looking to a 2030 horizon and the build-out of central Reno and Sparks, the plan projects a deficit of 37,287 acre-feet of water.
An acre-foot equals 325,851 gallons, the amount consumed by a family of four in a year.