California’s water demand: a look at the numbers

Nate Silver's datalab, aka 538, takes a fresh look at the numbers that show California's water demand. Leah Libresco digs up some real gems:

California’s water problem won’t be solved by shorter showers or browner lawns.

In Gov. Jerry Brown’s executive order setting California’s mandatory water reductions in cities and towns, he called for 25 percent reductions in use that would save 1.5 million acre-feet of water1 over the next nine months.

By comparison, the city of Los Angeles uses 587,000 acre-feet in a year. In other words, L.A. would need to go completely dry for three years to cover Brown’s goals on its own.

California’s urban areas are responsible for only 10 percent of the state’s water use.

That's putting it starkly, But leave aside the problem-solving aspect for a minute, and look at these numbers as values, as shown by the amount of water we as a state/culture devote to them.

If forty percent of our water goes to agriculture, and ten percent goes to the cities/people, then where does the rest go? To the environment:

…50 percent of California [is] reserved for environmental use (maintaining wetlands, rivers, and other parts of the state’s ecosystem)…

Is this number a fluke? Arguably not. About a decade ago, among the "water buffaloes" who devote their lives to working out this issue, a conciliation was reach regarding reworking the water management in the Sacramento-San Joaquin Delta.

As many readers will know, this is where water is sucked into the State Water Project through enormous pumps. But the important point is, a consensus was reached, a decade or more ago, that the environment was put on a level playing field with our use, and declared a "co-equal goal."

As recounted by Doug Obegi of the NRDC, as of 2009:

Today, California's Governor is signing into law SB 7X 1, part of the legislative package to reform water policy in the state.  The bill being signed today builds the foundation for a sustainable 21st century water policy, which is built on two interrelated principles:

  1. Improving water supply reliability and protecting and restoring the health of the Delta estuary, and its native fisheries, are co-equal goals for Delta policy (See Sections 85020, 85054, 85300); and

  2. In order to achieve these goals, the policy of the state is to reduce reliance on water exported from the Delta and invest in alternative water supplies, like water efficiency, water recycling, and low impact development. (Section 85021)

So, I think, one can argue that we have at least achieved our equity goal, here in California, even if we have all too little water to actually share.

To attempt to put this question in perspective visually, here's a (state) Department of Water Resources picture of one of the new pumps used to suck water out of the Delta and move it south.

Hitachi pump

These pumps, which wear out by the way, are driven by 80,000 horsepower motors.

One thought on “California’s water demand: a look at the numbers

  1. That 50% for environmental is basically every other drop that falls in the state. It is the uncontrolled water that is used for grasses and trees wherever it falls. Some of it is in Wild and Scenic rivers, but mostly it is just ‘all the other water’.

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