Napa on Tuesday approved the exchange of 7,000 acre-feet of water to the Santa Clara Valley Water District, earning the city $1.4 million for its own water system. Meanwhile, American Canyon authorized a 759-acre-foot transfer to the district, which covers Santa Clara County, for $150,000, while a third deal by Calistoga will produce $100,000 for 500 acre-feet.

All of the agreements involve “carry-over” water supplies, unused yearly allotments cities receive from the State Water Project channeling Sierra Nevada snowmelt to reservoirs and communities across California. The state allows cities to carry over only a certain amount of their allocations from one year to the next, leading some water agencies to offer their surplus to other cities that have maxed out their allowances and must get more water rights from beyond their borders. 

The deal with the Santa Clara Valley district is a partial exchange rather than a full sale because Napa, American Canyon and Calistoga will receive half of the water shares back within 10 years, according to city officials.
State law allows local water agencies to carry over no more than 35 percent of their maximum allotments from the State Water Project, according to Phillip Miller, engineer with the Napa County Flood Control and Water Conservation District. The district contracts with the state for Sierra Nevada water and passes it on to local cities.

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