2:30 p.m. (PDT)
State water officials say they will use satellite surveillance from high above farms in the Sacramento-San Joaquin River Delta as one way of confirming that fields have been left fallow under voluntary conservation agreements with farmers.
Growers with some of the strongest water rights in the delta east of San Francisco offered to reduce their water consumption this summer by 25 percent through several means that include leaving some land unplanted.
In exchange, the state agreed to spare the farmers deeper mandatory cuts later in the year.
Michael George, the delta water master, said Tuesday that officials will review satellite imagery taken every 16 days in addition to making site inspections of farms and requesting copies of irrigation schedules.
However, he says it's not an attempt to weed out cheaters.
"We want to monitor and figure out what all this effort means in terms of relief to the water system," George said.
More than 200 farmers had agreed to the program by a Monday deadline. It was unclear what percentage of delta farmers that figure represents.
Among other things, farmers intend to reduce crops such as alfalfa and plant crops that grow faster such as silage corn for livestock feed rather than corn eaten by people. Farmers say they will irrigate some crops once a month rather than twice.
"There's a great deal of creativity and management sophistication that's going into these plans," George said.
A new forecast says the economic impact of California's drought will grow by $500 million in 2015, to $2.7 billion.
The study released Tuesday by the University of California at Davis includes a one-third increase in the number of acres that farmers are fallowing for lack of water. The total is now 564,000 acres.
The study says the drought, now in its fourth year, will be worse for state farmers this year in terms of reduced water availability and economic impact to agriculture.
California is the country's leading state in terms of agricultural production.
Researchers say that even with increased groundwater pumping, state farmers in 2015 will run 2.5 million acre-feet short of the water they normally use.
However, the study says overall increases in crop prices are expected to remain modest in 2015, at less than 2 percent.
An acre-foot of water is enough to supply one to two households for a year.
11:15 a.m. (PDT)
A U.S. senator says a push by federal lawmakers to address California's water shortage will likely become an effort to help several Western states.
The move could complicate what has already proven a difficult task but also provide motivation for more senators to make drought relief a priority.
Alaska Sen. Lisa Murkowski, the Republican chairman of the Senate Energy and Natural Resources Committee, wrapped up a Tuesday hearing about the drought by saying it highlighted the need to take up a broader bill than Congress has considered in past sessions.
She said the situation is dire in California but the focus moving forward needs to be Western-wide.
Congress has struggled over the past three sessions to pass a drought relief bill. The House passed legislation that stripped away environmental protections to divert more water to farmers. But the Senate has refused to go that route.
Cannon Michael, a farmer from Los Banos, California, told lawmakers that he has left 2,500 acres unplanted because of the lack of water and may be forced to idle thousands of acres more pending regulatory decisions designed to provide more cold water for fish.
"There's no relief coming anytime soon," Michael said after the hearing.
Associated Press writers Scott Smith in Fresno, California; Ellen Knickmeyer in San Francisco; and Kevin Freking in Washington contributed to this report.