SACRAMENTO – For years, environmentalists have promoted water transfers as a cost-effective, fish-friendly alternative to new dams. But a federal judge’s decision to protect a tiny, endangered fish in the Sacramento Delta could jeopardize north-to-south water sales when transfers may be crucial.

The last drought provides a lesson on the value of water transfers. California was rescued from the 1987-92 dry spell by a then-relatively new water market. The transfers provided a combined 815,000 acre-feet – enough to meet the needs of 1.6 million households – in 1991 and 1992.

… Before reaching Los Angeles and San Diego, supplies from the north must flow through the Sacramento Delta’s 1,100-mile maze of waterways. Two-thirds of the state’s drinking water, including nearly 40 percent of all deliveries to San Diego County, meander through the delta.

In his Aug. 31 ruling, Judge Oliver Wanger ordered state and federal water managers to significantly reduce pumping from the Sacramento Delta to protect the 3-inch delta smelt.

Wanger’s decision threatens to reduce deliveries by as much as 2 million acre-feet – enough for 4 million households a year – to keep the delta smelt from being drawn into the pumps near Tracy.

California is in the throes of a dry spell that will squeeze supplies tighter unless desperately needed snow arrives along the Sierra Nevada and the Colorado River basin this winter.

Full article here.