American Canyon will continue looking to the proposed, massive Sites reservoir in Colusa County to someday help slake its thirst.
The city of about 20,000 residents is the only Napa County city without a local reservoir. It depends on the state’s North Bay Aqueduct that pumps water out of Barker Slough, a dead-end slough in the Solano County portion of Sacramento-San Joaquin Delta.
Supply reliability is tied to the Sierra snowpack that melts and sends water into the state’s Lake Oroville reservoir that feeds into the Delta. From year to year, it’s wait-and-see how much of the American Canyon allocation will actually arrive.
“During the drought, we were acutely aware we needed to find something,” City Councilmember David Oro said at the Feb. 5 City Council meeting.
The City Council unanimously approved spending $240,000 this year to continue participating in the Sites project. Among the few dozen other participants are Los Angeles, Sacramento, San Bernardino, Antelope Valley and Santa Clara.
Sites reservoir could be built by 2030 and would hold 1.8 million acre-feet of water, slightly more than Napa County’s Lake Berryessa (1 acre-foot is about 326,000 gallons of water). No river would be dammed. Instead, water would be pumped in during high winter flows from the Sacramento River and its tributaries, a city report said.
American Canyon is allocated 5,200 acre-feet of North Bay Aqueduct water annually, but in an average year receives 3,200 acre-feet. The city wants to have 4,000 acre-feet available in Sites reservoir as a hedge against dry years.
“Sites gives you better control to balance your portfolio of water supplies than what’s available today by the state or even the federal projects,” Sites Project Authority General Manager Jim Watson told the council.
The water would have to get from Sites to American Canyon. That would be done by releasing the water into the Sacramento River and having American Canyon pump the allocation from Barker Slough into the North Bay Aqueduct for local delivery.
Some City Council members expressed concern. The North Bay Aqueduct—which also provides Delta water to the city of Napa and to Calistoga, as well as several Solano County cities—faces issues of its own.
City officials said the aqueduct has capacity constraints because of biomass built up on the inside of the pipe. Plus, the rare Delta smelt can prompt pumping restrictions to avoid having fish sucked up and killed. Plus, dead-end Barker Slough has water quality problems.
“Because that straw is small or dirty or whatever it is, is there ever a time when we couldn’t get the water we needed?” Oro said.
Public Works Director Steven Hartwig didn’t mention any immediate problems. At times when water demand in the two counties is the greatest, most Solano County cities use Lake Berryessa reservoir water, he said.
“So far, the capacity overall and the constriction hasn’t really been an issue because of the timing of when everybody takes their water,” Hartwig said.
Long-range, the plan is to build new North Bay Aqueduct pumps in the Sacramento River, away from the Barker Slough smelt and water quality issues.
The Sierra Club has opposed building Sites, instead encouraging such alternatives as better groundwater management. The group sees environmental problems even for a proposed reservoir that doesn’t involve damming a river, given filling it would involve siphoning off Sacramento River winter flows and flooding a valley.
Hartwig described how Sites could help the environment. The reservoir would release water at times that would provide the greatest environmental benefits, he said.
“That’s the reason our state and federal partners are interested in this — because it helps support the health of the Delta,” Hartwig said.
American Canyon’s cost to participate in the Sites project was included in the city’s 2018 water rate study and the water rates approved by the council in May 2018, a city report said.
The city decided in February 2017 to participate in the Sites project. To date, the city has spent $120,000 in the hope that it will one day be receiving Sites water. The $240,000 approved on Feb. 5 is the latest installment to continue as a partner.