Davis is poised to dramatically change its water source after voters Tuesday appeared to pass a measure enabling the city to draw from the Sacramento River.

Measure I asked whether Davis should move ahead on the $245 million Surface Water Project with neighboring Woodland to supplement the cities' groundwater with Sacramento River water.

The measure was leading 55 percent to 45 percent late Tuesday with nearly 13,000 ballots counted, according to the Yolo County Elections Office. Voters decided through a special all-mail contest, and officials had tallied most ballots ahead of the election's close Tuesday.

The project is designed to supply 30 million gallons of water a day to the cities – 12 million to Davis and 18 million to Woodland.

Supporters said a river source would ensure a clean, long-term water supply for Davis while saving millions of dollars by working with Woodland. The project was backed by Davis and regional leaders and area trade unions. Davis Mayor Joe Krovoza called the turnout "tremendous for a mail-in ballot. It shows how this community put its arms around this issue."

"We have entered the modern world of water management," Krovoza said. Adding river water as a source, he suggested, would "extend the life of our groundwater forever."

The two Yolo County cities had worked since 2009 on the ambitious plan. The need became ever more urgent, both cities' leaders said, by aging wells, deteriorating water quality and quickly approaching deadlines for state and federal clean water requirements.

But opponents said the project and planned rate hikes to fund it were far too costly, came at the expense of other regional alternatives and overstated deterioration of the wells that supply the city's water.

Opponents did not concede late Tuesday.

"Our point is that they don't have a mandate," said Nancy Price, who worked on the No on I campaign. "First, the votes are too close, and we still have to see if the rates are approved."

Davis' share of the project would cost the city as much as $116 million before water purchase, operations and other costs.

Opponents called on Davis leaders to renew talks with West Sacramento to treat and furnish Davis' water supply. They also suggested that the city craft a regional water solution with West Sacramento, Woodland and UC Davis, instead of the planned water treatment plant and pipeline at the 17,300-acre Conaway Ranch on the Sacramento River.

Woodland, plagued by aging infrastructure, poor water quality and impending 2016 clean water deadlines, had already begun to move ahead on the project last summer.

Woodland Mayor Skip Davies praised Davis council members for their work on the project. If Measure I had failed, Davies said, his city was prepared to go it alone.

"We think the residents of Davis made a wise choice, " Davies said.

In Davis, disputes and anxiety over the cost, size and scope of the project dominated.

City leaders delayed a November city vote asking residents to support the project until March, while they considered several smaller, less expensive options, including a deal to have West Sacramento treat and supply Davis' water. But the cities did not reach agreement.

Concerns about the influence of out-of-town unions and developers on the Davis decision that arose in an earlier race for City Council resurfaced in the final days of the Measure I fight.

Opponents called the project, partially on land controlled by Sacramento developer Angelo K. Tsakopoulos, a river grab to attract development to the city. The proposal is backed by regional political leaders.

But Krovoza said the shut down of a major city well in late February for manganese contamination proved the urgency of moving ahead on the project.

"We can't run a city of 65,000 with a university with a daytime population of 55,000 on groundwater alone," Krovoza said last week.

Call The Bee's Darrell Smith, (916) 321-1040.

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