GRAND JUNCTION, Colo. (AP) - Voters here might get a chance in November to decide whether the city should have its own regulations for energy development in its watershed.

The city clerk Thursday certified that 2,635 signatures of registered voters out of the 4,270 on petitions turned in by the group Concerned Citizens Alliance for the proposal were valid. Only 1,580 were needed to qualify the measure for the ballot.

The Grand Junction City Council is expected to decide Wednesday whether to put the measure on the ballot or consider passing the proposal itself.

The alliance, the local chapter of the conservation group Western Colorado Congress, launched the initiative drive after federal oil and gas leases were sold in areas supplying drinking water for Grand Junction and neighboring Palisade.

"The incredible outpouring of support this issue received from the business community, churches and from citizens of every background proves that protection of our water supply is a truly a matter of common sense," said Janet Magoon, a local school teacher.

About 13,000 acres in watersheds for Grand Junction and Palisade were among roughly 135,000 acres leased in a February auction by the Bureau of Land Management. The federal government owns the minerals under the land.

BLM officials have said they've listened to the concerns of Palisade and Grand Junction, and looked at strengthening the development guidelines if companies apply for drilling permits. Last week, the BLM rejected the cities' protests of the leases, but has suspended development for a year to try to address residents' concerns.

The Colorado Oil and Gas Conservation Commission is the main state agency that regulates the industry. Through an agreement with the state health department, the commission carries out state water regulations that apply to oil and gas operations.

If the initiative passes, Grand Junction would have to mandate water-quality protections not in existing city, state and federal laws.