Good news, bad news for California: we’re well-prepared but still vulnerable

California is both highly prepared and highly vulnerable to the effects of climate change on its water systems, according to two recent studies.

Released today, the National Resources Defense Council’s “Ready or Not” report ranked states in terms of overall water preparedness. The rankings took into account susceptibility to various climate-related factors – such as coastal erosion, saltwater intrusion and flooding – as well as steps being taken to curb carbon emissions and to recognize and tackle vulnerabilities to a changing climate.

In spite of California’s high susceptibility to shifts in climate, the NRDC found California to be one of the most proactive states in the country at factoring climate change into water planning and policy.  According to Ben Chou, a NRDC water policy analyst, California earned high marks for its aggressive efforts to curb greenhouse gas emissions and for its development of a statewide climate preparedness plan.

“The best-performing states [in the study] have taken a comprehensive approach and are trying to address each one of these challenges,” said Steve Fleischli, an NRDC attorney. “Some of the worst-performing states have measures to address water conservation. They just don’t put it in the context of a changing climate.”

But just because a state has written climate change into its water planning doesn’t mean it is necessarily prepared for disturbances that can result from, say, a serious flood or drought.  “States like California might have very comprehensive plans but the rubber meets the road with implementation,” Fleischli said.

Sharper criticism for California’s water management came in a report issued last week by the National Academy of Sciences. The study, “Sustainable Water and Environmental Management in the California Bay-Delta,” focused on declining ecological conditions and the role of the Delta as hub of the State Water Project, the system of reservoirs, aqueducts and canals that delivers water to vast tracts of farmland and millions of residents in central and southern California.

The report highlighted several potential threats posed by climate change to the Delta, including:

• Earlier, faster melting of the Sierra snowpack will continue to push the timing of runoff earlier in the year. This, in turn, will reduce the storage capacity of reservoirs in the foothills and diminish the volumes of water available for mid-summer “cold releases” (vital for maintaining freshwater fish populations downstream)
• Sea level rise caused by global warming will substantially increase the risk of levee failure and potentially reduce the volume of freshwater exported from the Delta for California’s drinking and agricultural water supplies, by as much as 25% by the end of the century
• Warming water temperatures may disturb a range of aquatic life in the Delta, including salmon, which at higher temperatures become more susceptible to disease and mistimed spawning
• Warming air temperatures in the region may increase the water demand of Delta farms by as much as ten percent by 2040

The NAS report cited a lack of “integrated, comprehensive” management and transparency among a far-flung array of stakeholders and agencies as hurdles to improving management and the health of ecosystems of the Delta.

Sponsored by the U.S. Fish and Wildlife Service, the report is the second in a series on the Delta. The first report, released two years ago, focused more narrowly on increased water diversions and the consequences for threatened and endangered Delta fish species including steelhead, Chinook salmon, Delta smelt and green sturgeon.

Like the NAS, the NRDC also points to the Delta and its 1,100 miles of levees as the state’s most vulnerable region to flooding: “Approximately $69 billion in assets,” states the report, “including the state’s water supply, major freeways, agricultural land, and natural ecosystems, is protected by this levee system.”