The opening salvo has been fired in what officials expect to be a long and expensive battle to boost El Dorado County's water supplies.

But the El Dorado Water and Power Authority doesn't anticipate having to fight the city of Sacramento for that water.

El Dorado needs water to serve a growing population and as a hedge against drought. But Sacramento also gets water from the American River, and the amount of new water allocations for municipalities is limited these days by drought and environmental concerns.

So instead of wrestling with Sacramento, the El Dorado authority is applying for annual rights to 40,000 acre-feet of water from the American River and Folsom Lake now held by the state.

"This won't take any water from the city of Sacramento," said Bill Hetland, the water and power authority's executive director and general manager of the El Dorado County Water Agency.

But he said, "Any time you take water out of a system, there will be impacts downstream."

The public may comment on what issues they think should be included in the environmental study for the Supplemental Water Rights Project during meetings Wednesday in Placerville and Nov. 17 at the SMUD Auditorium in Sacramento.

The water and power authority consists of El Dorado County, El Dorado County Water Agency, El Dorado Irrigation District and Georgetown Divide Public Utility District. It seeks the additional water to take advantage of delivery and storage capacity acquired in a 2005 from agreement with the Sacramento Municipal Utility District.

Under the agreement, El Dorado County water suppliers could use SMUD's Upper American River Project facilities to deliver 30,000 acre-feet of water annually through 2025, and up to 40,000 acre-feet per year thereafter.

An acre-foot is the amount of water that will cover an acre to the depth of one foot.

In 1957, SMUD assigned to Sacramento rights to water that flows through its system of 11 reservoirs and eight hydroelectric plants on the upper American River. But El Dorado County and water district officials say the state contract granting Sacramento rights to El Dorado County water specifies that those rights may be taken back at such time as the county needs the water.

The water and power authority initially sought to buy water from the city of Sacramento. But the city maintained that any excess water reverts to the federal Bureau of Reclamation. The bureau, in turn, has said the water is committed to Central Valley Project users.

"Now, we're ignoring all of that," Hetland said.

The water and power authority's application seeks assignment of rights that the state acquired in the 1920s and has held in reserve for future needs.

Kathie Smith, a spokeswoman for the California Water Resources Control Board, said in an e-mail that two state-filed rights, filed in 1927, exist for the American River.

"The rule for priority rights is 'first in time, first in right,' " she said. "If the state decided to allow assignment to (the El Dorado Water and Power Authority), the Authority would get the 1927 priority date."

Smith said the authority currently is the only petitioner for those rights.

But she said, "Although the state-filed applications have a certain amount that is set aside for priority, there is no guarantee the water is available. There is a process to determine that."

Hetland said he expects the environmental impact report to be completed next fall, and a hearing before the state board would follow. The process could take from two years to more than a decade, he said, adding that opposition is anticipated.

But having spent $582,000 on state application fees, Hetland said, the authority's member agencies are invested in the pursuit.

Call The Bee's Cathy Locke, (916) 608-7451.