KQED is reporting today on a new study suggesting that California and the Southwestern US have reached what they’re calling “peak water” – similar to the concept of peak oil, where water demand is outstripping supply:

The concepts of peak oil and peak water aren’t entirely analogous for a number of reasons, not the least of which is the fact that, overall, water is a renewable resource.  But there are limits to what water is renewable, and how fast supplies recharge.  While the world is not going to run out of water, the report authors argue, in parts of the world including the southwestern US, we’re likely long past the point of peak water.  That matters a lot, said study co-author Meena Palaniappan, because unlike oil, which is shipped across the world, water is still a local and regional issue.

“We’re not going to run out of water,” said Palaniappan, “but we’re going to see a change.  We’re at the end of cheap, easy access to water.  We’re going to have to go further, pay more, and expect less in terms of fresh water.”…

In the western US, we are definitely past peak ecological water, said Palaniappan.  As evidence of this, she cited the Central Valley aquifer, which is being pumped down far faster than it can recharge and the Colorado River, which supplies Southern California with much of its water, and no longer reaches the ocean most years because every drop of it is appropriated for human use.

The Monterey Peninsula is quite familiar with this phenomenon, having long ago overshot our carrying capacity based on local aquifers and rivers. Since we’re not tied into the state water system, Monterey depends on local sources. And we’ve already grown beyond what those local sources can provide.

Since 1999 the region has been under water conservation orders, resulting in a virtual standstill on approving new water hookups, and the state water resources board has ordered a major reduction in pumping out of the Carmel River. If we want to even maintain the current level of water usage, or have any new growth, we need to build a desalination plant, and one is proposed for Moss Landing.

But that’s just for the Monterey region, with a population of less than 150,000. What of the 38 million Californians who depend on water sources that are becoming overdrawn and more difficult to replenish?

The upcoming November vote on the $11 billion water bond will help determine how Californians respond. The water bond proposal locks in some of the worst abuses and misallocations of water in the state, especially for suburban sprawl and irrigating marginal lands in the westside of the San Joaquin Valley, along with a Peripheral Canal. If the bond is rejected, however, Californians would potentially have the chance to chart a course toward more sustainable water use.

Especially considering the likely effect of global warming on California water systems, with a reduced snowpack, it’s important that we get it right instead of merely finding ways to prolong the current water usage system when it is no longer viable.