The federal government has warned that it would reduce Southern California's access to the Colorado River early next year if the deal was rejected instead of over 15 years as foreseen in the original plan.

The Imperial Valley Irrigation District rejected a plan to sell water to San Diego to make up for the shortfall in water from the Colorado.

California has been forced to reduce its use of Colorado River water by rapidly growing neighbors such as Arizona, and by a federal year-end deadline to reduce its consumption from the river, whose water is shared by seven U.S. states and Mexico.

Ron Hull, a spokesman for the Imperial Irrigation District, east of San Diego, said the board rejected the deal reached in October because it required too much farmland to be taken out of production, thus threatening jobs in a community with an unemployment rate of about 22 percent.

"The tentative settlement was rejected because the deal posed too big a risk to jobs in this community," Hull said.

Many farmers fear they will be asked to leave more land unplanted after the first 15 years of the roughly $2 billion deal, which could last up to 75 years.

They also fear becoming another Owens Valley, a farming community in the eastern Sierra Nevada that dried up after water was diverted from the farming community to Los Angeles back in the 1920s.

The board also rejected the deal because of concerns over the impact fallowing might have on the nearby Salton Sea, a shallow, salty desert lake that depends on agricultural run-off and is an important habitat for birds.

THE OCTOBER DEAL

Hull added added there were no plans "in the foreseeable future" for a second vote on the deal, putting the state closer to missing a Dec. 31 deadline to have an arrangement in place to reduce its water use from the Colorado River.

But the Imperial Irrigation District did propose on Monday to put together a plan that might satisfy the year-end deadline - if reviewed and approved quickly - by transferring water to San Diego over a three-to five-year period.

The U.S. Department of the Interior has threatened to cut California's excess use of Colorado River water - about enough for 1.6 million families - by year-end if a plan is not in place.

To reduce its use of the river, California would rely heavily on the farmers of the Imperial Valley, diverting water from farms through existing water canals to fast-growing suburbs in San Diego.

The Imperial Valley takes about 70 percent of California's water from the Colorado River using valuable water rights secured a century ago to produce everything from citrus fruit and dates to vegetables, flaxseed, hay and pasture grasses.

Under the seven-state agreement reached in October, California would reduce its excess draw from the Colorado river by about 1 percent a year over a 15-year period, gradually reaching new, lower target levels.

Under deals reached several decades ago, the Metropolitan Water District of Southern California (MWD) could see about 800,000 acre-feet of water immediately cut off at year-end - instead of the 15-year period stipulated in the deal - if the state misses the federal deadline, Hull said.

Adan Ortega, an MWD spokesman, said if the Interior Department cut off its excess Colorado River water the agency would still have enough water for all its 17 million Southern California customers over the next two years.

Longer term, the water district will step up conservation efforts, increase water storage capacity, and begin generating drinking water from desalination plants to make up for the loss of excess Colorado River water, Ortega said.

One acre-foot of water is about 326,000 gallons (1.48 million liters), or roughly enough to meet the needs of one three-to four-person family a year, according to the Association of California Water Agencies.