DUBLIN -- The East Bay's fastest growing city will consider a major development decision Tuesday when the City Council considers two rival ballot measures on regulating land use in Doolan Canyon east of town.

A developer has eyed the sparsely settled canyon as a site for 1,900 homes. Environmentalists want to preserve the canyon as an open space buffer between Dublin and Livermore.

Two rival groups each have collected enough signatures to put their competing measures on the November ballot in Dublin unless the council uses its powers to adopt one of the measures outright.

If the council adopts one measure, the rival one likely would go on the ballot, backers of the two measures say.

The council will meet at the special time of 5:30 p.m. Tuesday at the Dublin Civic Center to consider the rival measures.

Environmental groups and some Dublin residents say their "Open Space Initiative of 2014" would curb urban sprawl by requiring Dublin voters to approve any plan to annex Doolan Canyon to Dublin and build there.

The initiative would designate Dublin's eastern city border as the city's urban limit line -- with Doolan Canyon outside those growth limits.

"Our measure would stop development in Doolan Canyon unless Dublin voters approved it," said Morgan King, a Dublin attorney who helped write the initiative. "With the other measure, it only takes three votes on the City Council to approve development in Doolan Canyon."

Dublin has a western urban limit line, but not one on the east side where the fastest growth is occurring in this city of more than 53,400 people.

Morgan said his measure would protect against sprawl that causes excessive traffic congestion, school crowding, loss of open space and more strain on limited water supplies

The Sierra Club, Save Mount Diablo and other environmental groups have helped collect signatures for the open space initiative.

In the other camp, former Dublin Mayor Janet Lockhart said the "Let Dublin Decide Initiative of 2014" that she backs would let Dublin decide the future of Doolan Canyon by bringing the area under city control.

"This initiative isn't about a project, but about who should decide what happens in this area," Lockhart said. "Dublin should decide."

Lockhart said bringing Doolan Canon under Dublin's control would ensure its land use future is not left up in the air to be possibly decided some day by Alameda County or the city of Livermore.

For their part, Livermore officials say they continue to strongly support preserving Doolan Canyon as open space.

Lockhart replied that the Livermore City Council could change its mind after future elections.

"If the Dublin open space initiative passes, control could shift to Livermore," she said.

Dublin City Councilman Abe Gupta said he considers it far-fetched to think Livermore would want to develop Doolan Canyon.

Gupta said he supports the open space initiative and intends to vote Tuesday for the council to adopt the measure outright, and leave it to voters to decide on the rival measure.

"I think the open space initiative is a message" that always expanding is not the way to go, Gupta said. "We need smart growth."

Dublin city officials said Friday they were still trying to sort out which of the two measures would become effective if the council adopted one measure, and voters adopted another.

Contact Denis Cuff at 925-943-8267. Follow him at Twitter.com/deniscuff.

If you go
WHAT: Dublin City Council will consider two competing initiative measures that take different approaches to regulating development in Doolan Canyon.
WHEN: 5:30 p.m. Tuesday
WHERE: Dublin Civic Center, 100 Civic Plaza.