Surface air temperature change (2050s average minus 1971-2000 average), NOAA GFDL CM2.1 Climate Model, SRES A1B scenario.   This world map shows the projected change in annual mean surface air temperature from the late 20th century (1971-2000 average) to the middle 21st century (2051-2060 average). The change is in response to increasing atmospheric concentrations of greenhouse gases and aerosols based on a "middle of the road" estimate of future emissions.  Warming is larger over continents than oceans, and is largest at high latitudes of the Northern Hemisphere. These results are from the GFDL CM2.1 model, but are consistent with a broad consensus of modeling results.

By Elaine S. Povich, Stateline

With all the attention focused on California's water woes, an observer might conclude that the Golden State's drought is the exception. It isn't. Forty states expect to see water shortages in at least some areas in the next decade, according to a government watchdog agency.

In a 2013 survey by the Government Accountability Office (GAO), state water managers from around the country said they expect freshwater shortages to continue into the next decade, even under what they described as "average" conditions. If those conditions change — whether because of rapid population growth, unusually low snowfall or rainfall, or accelerated economic growth — the situation could worsen.

"As far as other states, if they haven't seen it in the past, it's something they will see in the future," said Ben Chou, a water policy analyst in the Los Angeles office of the Natural Resources Defense Council, an environmental group.

Late last month, Democratic California Gov. Jerry Brown implemented mandatory water conservation rules. The rules ban all restaurants, bars and hotels from serving water unless customers ask for it, ban the watering of lawns and landscaping within 48 hours of measurable rain, and require municipalities and private companies to limit lawn watering to two days a week.

The lawn-watering limits are likely to have the most impact, since outdoor irrigation makes up 44 percent of water use in the state's urban and suburban communities, according to the state water board. The past three years have been the driest three years in California history dating to the 1849 Gold Rush, the board said. Low snowpack, combined with 2014 being the hottest year in history in the state, exacerbated the situation.

Residents of other states should take a lesson from California, Chou said. "Attention on California is due to the size of the state and the fact that we grow about half of the nation's produce," he said. "Other states have started looking at it, especially where water supplies are at a premium."

Montana, for example, was listed in the GAO report as the state most likely to have a statewide water shortage in the next decade. Many other western states are in a similar predicament.

Tim Davis, Montana Water Resources Division administrator, said his department told the GAO that in any given year, any part of the state could have a water shortage. He said that last year, most of the state was fine, but the southwest corner was dry. Entering this irrigation season for farmers, Davis said the southwest region remains dry as is "much more of the state."

Under direction from the Montana Legislature, Davis said his department has begun to plan for water shortages.

"Drought is one of those disasters that you have to plan for," he said. "You can't just immediately go out there and change how you're using water on the ground or invest in efficiencies unless you have been doing it all along." He said the state is making plans to share water between communities during times of drought, along with changing field irrigation methods to save water.