What Climate Change Means for California’s Water

Yesterday the National Oceanic and Atmospheric Administration and NASA concurrently declared 2015 as the warmest in 136 years of record-keeping.

This news came as California’s Water Commission was meeting to discuss a host of issues, including how climate change should be included in water resources planning. The state has declared that “climate change is having a profound impact on California water resources” and undoubtedly will in the future, too.

A presentation at the commission meeting by Elissa Lynn of the Department of Water Resources (DWR) explained how climate change is impacting the state.

Here are some pertinent facts:

• California is getting warmer. In the last 100 years, average temperatures have increased 1.1 to 2 F.
• Things will likely get even hotter, with estimates of average temperatures by 2060 to be 3.4 to 4.9 degrees warmer than during the period between 1985 to 1994.
• Precipitation is shifting from rain to snow, which will decrease snowpack, a crucial component of California’s water supply.
• Think extremes: Droughts will become longer and more frequent, and flooding will worsen.
• By 2100, Sierra snowpack may see a 48 to 65 percent decrease.

DWR has a three-phase plan for tackling climate change’s impact on California’s water resources. The first is to reduce or prevent greenhouse gas emissions (made harder at the moment by a raging gas leak in Southern California). The next phase is to help water managers access the best science. And third is to assess the system’s vulnerabilities and plan for adaptation – no small feat.

Not everyone thinks the plan goes far enough. Climate scientist Juliet Christian-Smith of the Union of Concerned Scientists wrote: “They also require project planners to build for what is being termed a ‘median’ scenario – not for a range that includes more extreme scenarios that would significantly stress the system.”

Expect to hear more from Gov. Jerry Brown about climate change during his State of the State address today.

Desert Town Fast Depleting Only Drinking Water Source

Borrego Springs is on borrowed time. The California desert town 60 miles northeast of San Diego has only one source of water – a groundwater aquifer – that water users are draining four times faster than it can be replenished.

Without some significant changes, the Borrego Valley faces tough choices as farmers (which use 70 percent of the water pumped from the aquifer), residents, businesses and the Anza-Borrego Desert State Park compete for water resources.

The scenario is similar to other areas of the state, most notably in the Central Valley, where we are just beginning to fully take stock of the implications of decades of groundwater overdrafting, which are threatening infrastructure and communities. Currently 40 percent of Californians rely on groundwater for some or all of their drinking water and in drought years, groundwater use increases.

That may be what prompted a six-year study by the U.S. Geological Survey and Borrego Water District to analyze 60 years’ worth of water data from the area to better understand the situation.

The study found that in some areas, overdrafting of groundwater has caused aquifer water levels to fall more than 100 feet. Some wells are now running dry, and water quality has suffered as deeper wells are pulling up salty, arsenic-tainted water, according to the Los Angeles Times.

So what’s a thirsty desert town to do?

There clearly isn’t enough precipitation and runoff to meet the area’s future needs with business as usual. But the study points to other sources of water for groundwater recharge and the reuse of irrigation water. An increasingly popular option is using recycled water – treated wastewater that is then injected back underground to help fill diminishing aquifers.

Thanks to groundwater legislation passed in 2014, the water district has 20 years to figure out how to stop overdrafting the aquifer, unless nature moves up that deadline.

Almonds to the Rescue in Drought Research

Almond orchards, much maligned by some during California’s drought, are at center stage this week for an experiment that may help the state save water.

Researchers from UC Davis flooded an idle almond orchard with stormwater from Modesto, and in the coming months will track how the water seeps into an underground reservoir.

It’s an experiment in water banking that could inform how water managers are able to store excess water in wet years for later use.

Although as Lisa M. Krieger writes for the San Jose Mercury News, there is still a lot to learn. “Is the water clean enough? Will it drown the valuable trees? Could it introduce waterborne diseases or make trees more vulnerable to insect pests?” she writes.

Top image: In this Sept. 17, 2014 file photo, firefighters battle the flames from the King fire near Fresh Pond, Calif. New scientific analysis shows the fingerprints of manmade climate change on 14 extreme weather events in 2014. (Rich Pedroncelli, Associated Press)