Climate change certainly has a huge effect. Increased evaporation, decreased snowpack, the stalling of air masses that cause more drying and less wetting, which in turn is caused by changes in the jet stream, which in turn is caused by "Arctic Amplification," an effect of global warming, are major causes of a three year drought coming hard on the heels of a decade of near-drought dry.
But also, Californian approaches to water management have been an issue. I recently learned that there are communities in California that don't even have water meters on people's houses. What the heck? A while back the state asked people to use less water. They didn't. Just now, the California Water Board implemented a fine for overuse of water, and local communities are asking people to turn in their neighbors who do so.
Here is an interview on All In with Chis Hays of Peter Gleick of The Pacific Institute, on the drought and the response to it.
I recently learned that there are communities in California that don’t even have water meters on people’s houses. What the heck?
It's one thing to do this with people who get their water from private wells, which is a common arrangement in the area where I live. But I don't think there are many places in California where you can do that, and the places where you can are presumably lightly populated, since you can't support much population without a water supply infrastructure. (That's true even here--it's one of the few good reasons for minimum lot sizes of two acres or more, which exist in part or all of most towns in this state--and we average more precipitation annually than Seattle.) It's mind-boggling that there would be no effort to monitor water usage in a place where water rights are such a big deal.
One other item in urban Ca it turns out they plant oleanders along the freeways and of necessity have to irrigate them. Now they don't do it in the Mohave (i-40) however. Ca is the only place I have seen much of this in the US. I do wonder what kind of message it spends when so much water is used on irrigation of ornamental vegetation that is seen every day by folks. Even if it is recycled water, it could be diverted to keep food crops growing. But then I would ban all watering of ornamental landscaping period.
Water is affected by both use and climate change, so we're seeing both depletion and changes in hydrological cycles. Climate change affects surface water and the replenishing of aquifers. Usage depletes aquifers and reduces surface flows. An article in Circle of Blue cites “climate change, population growth and profligate use” as the main factors behind America's water problems. Also soil erosion, leaky pipes, and, tellingly in the context of your present political environment, “an aversion to conservation.”
Internationally water shortages are increasingly becoming a problem and a cause of conflict in the Middle East. The shortages in California are at present the most salient U.S. example, but the entire area supplied by the Colorado River is becoming more vulnerable. In addition to this you have the depletion of aquifers.
“While agriculture in the Colorado Basin faces shortages, farmers to the east in the high plains — tapping the Ogallala Aquifer — have progressively seen their wells dry up. The aquifer is the largest in the United States and sees a depletion rate of some 12 billion cubic meters a year, a quantity equivalent to 18 times the annual flow of the Colorado River. Since pumping started in the 1940s, Ogallala water levels have dropped by more than 100 feet (30 meters) in some areas.”
“...The prognosis for farmers, whose irrigation accounts for 94 percent of the groundwater use on the high plains, does not look optimistic. In the future, irrigation may not be possible at all as the levels continue to drop past the well intakes of farmers. More likely, before the pumping stops, the cost of drilling and maintaining deeper wells may exceed the value of what can be grown, severely limiting the farmland’s value. 'There is no other water available,' said Dennehy.” [“Kevin Dennehy, program coordinator for the Ground-Water Resources Program at the U.S. Geological Survey.”]
Aquifer depletion also leads to land subsidence, and in some cases this permanently reduces storage capacity. (As well as causing various types of structural damage.)
There is only one way people use LESS when asked...Raise the price until they have to use less. In the western area where much is arid land and the dim people try to have grassy golf-coarse style lawns demonstrate that 'dim' is way to weak a term. When you move and live in an environment then accept where you are or move. When resources are depleted then adapt or MOVE!!!
Here in Austin, more or less voluntary water conservation is working so well that next month I will have a $2.35 surcharge on my water bill. Water use has dropped enough that a surcharge is necessary (it is said) to keep the water system solvent.
California's drought-ravaged reservoirs are running so low that state water deliveries to metropolitan areas have all but stopped, and cutbacks are forcing growers to fallow fields. But 19th century laws allow almost 4,000 companies, farms and others to use an unmonitored amount of water for free -- and, in some cases, sell what they don't need.
With grandfathered legal rights, this group, dominated by big corporations and agricultural concerns, reports using trillions of gallons of water each year, according to a review by The Associated Press. Together, they have more than half of all claims on waterways in California.
However, the state doesn't know if any are overdrawing or wasting water. The AP found the state's system is based on self-reported, incomplete records riddled with errors and years out of date.
The system’s inequities are particularly evident in California’s arid Central Valley.
“In a good year we wouldn’t be able to stand here unless we got wet. This year it won’t produce anything,” said second-generation rice farmer Al Montna as he knelt in the dust, pulling apart dirt clods on the 1,800 acres he left idle because of scarce water.
About 35 miles north, fourth-generation rice farmer Josh Sheppard had more than enough water, thanks to his water district’s superior rights to Feather River water dating to the late 1800s.
“No one thinks of it when there’s ample water and plenty to go around, but in these times of tightness it is a very contentious resource that gets fought over,” Sheppard said, standing next to his flooded fields.
While much of the water reported by this group is consumed by people or farms, some of the biggest users generate hydroelectric power for profit then return that water to the river for use downstream. The state doesn’t know how much is used for each purpose.
This year, the state cut water deliveries to farmers and cities by 95 percent, and the federal government also imposed sharp restrictions on its water customers. But companies, farmers and cities with water rights that pre-date 1914 were exempt this year from mandatory cuts, even though they collectively are the biggest water users in the state.
The AP independently verified that just 24 of the rights holders reported using more than twice the volume of water that California’s vast system of state and federal dams and aqueducts ships to cities and farms in an average year.
As summer looms, some water scientists question the utility of conservation efforts that do not restrict consumption by most water users with old rights. “Obviously, senior water rights holders have the most to benefit from the current system,” said Peter Gleick, director of the nonpartisan Pacific Institute.
The water board does not require monitoring or meters for users whose rights date back a century or more, or who have rights to draw from a waterway adjoining their land.
Rights holders have successfully defeated legal and legislative efforts to strengthen California’s oversight, said Andy Sawyer, a board attorney.