A bounty of state-supplied water reserved for Napa will provide the city with $1.06 million to keep its water treatment and pipes in shape.
Six thousand acre-feet of Napa’s allotment with the State Water Project – which channels Sierra Nevada snowmelt to cities across California – will be transferred to the Kern County Water Agency in the southern Central Valley, in a deal the City Council approved Tuesday. Kern County also agreed to return a third of that share to Napa within 10 years.
The sale will draw on the 10,950 acre-feet of state-controlled water granted to Napa in the 2018-19 fiscal year, on top of another 9,310 acre-feet of unused supplies from past years.
One acre-foot equals about 326,000 gallons.
City officials called the sale a way to fund upkeep of its water treatment and delivery network with supplies fattened in the last two years by conservation in the face of a statewide drought – and the winter rains of 2017 that broke the drought. Napa will not divert any water from Lake Hennessey or Milliken Reservoir, its two sources within the county.
Napa chose to sell some of its excess supply rather than risk potentially losing it to a spillover at San Luis Reservoir, a state facility in Merced County, according to city utilities director Philip Brun.
While cities can bank unused state water from one year to the next, those reserves can be reduced if the reservoir reaches its capacity and spills, preventing a city from cashing out on that surplus. State law also limits local water agencies from carrying over more than 35 percent of their maximum allotments from the State Water Project.
The water exchange with Kern County will be Napa’s second in as many years. In 2016, the city passed 7,000 acre-feet of its state allotment to the Santa Clara Valley Water District, receiving $1.4 million in return with a promise to get back half of that water share within a decade.
Water demand has dropped in Napa in recent years, which have seen a year of state-mandated 20 percent cutbacks that began in 2015 amid five years of statewide drought. Meanwhile, the winter of 2017 brought unusually heavy rainfall to the North Bay, filling local reservoirs and even causing the city to use its Oxbow Commons – a downtown park in the dry seasons – as a flood-control bypass of the Napa River for the first time.
Total water use by city customers was about 13,500 acre-feet in 2017, down some 2,000 acre-feet from two years earlier, according to city water manager Joy Eldredge.
A sale of state water rights is one way for Napa to make up for declining sale revenues city officials say are partly the result of increased conservation and efficiency. Citing the need to keep up with maintenance costs that remain constant even with lower water use, Napa in November approved a series of annual water rate increases that will take effect through 2022.