ST. HELENA — The City Council has approved a short-term plan to bypass more water from Bell Canyon Reservoir into Bell Creek, in response to a lawsuit claiming that the city has degraded fish habitat in the creek by historically capturing too much water in the reservoir.
The council also approved contracts to install equipment measuring how much water the city diverts from Bell Creek, and to conduct studies that will lay the groundwork for a permanent bypass plan within the next 12 to 18 months.
Mayor Alan Galbraith said that although he voted for the interim bypass plan, the council will need to pay close attention to the upcoming technical studies to ensure that the final plan will not significantly affect the city’s water supply.
The council’s actions on Tuesday drew praise from Water Audit California, an environmental group that filed a lawsuit in 2016 claiming the city had historically diverted too much water from Bell Creek into Bell Canyon Reservoir, one of St. Helena’s three primary water sources. The actions taken Tuesday comply with a settlement agreement approved last August.
Water Audit’s advisory board concluded that the interim bypass plan “reconfigures releases to more closely mirror natural events” without resulting in “unacceptable loses to the City’s deliveries,” according to a Feb. 8 letter from Grant Reynolds, a director of Water Audit.
“It provides for monitoring and measuring to contemporary standards, and agrees upon the course of further scientific investigation by proposing a stream study that will be used to create the final bypass plan,” Reynolds wrote. “Bravo!”
Water Audit’s lawsuit claimed that the city’s failure to bypass sufficient water into Bell Creek contributed to the decline of steelhead, which haven’t been found in the creek downstream of the reservoir since before 1990. Reynolds and Water Audit have pursued similar litigation against the city of Calistoga and the California Department of Veterans Affairs, which operates Rector Reservoir outside Yountville.
The interim plan approved Tuesday requires the city to bypass more water from the reservoir to the creek between Nov. 15 and April 15. The city’s permit already prohibits the city from storing water that enters the reservoir between April 16 and Nov. 14.
A biologist hired by the city recommended the bypass flows contained in the interim plan. According to a staff report, hydrologists concluded that the flows “would have a minimal impact on the storage volume of the reservoir and would not require the City to tap any other sources of water to make up for the difference.”
Most of the additional water that will be bypassed was already being released over the reservoir’s spillway when it was at full capacity, the hydrologists calculated. The new flows would only affect the city’s water supply during drought years, and even then the difference would be small, they concluded.
For example, in 2014 the reservoir was 95 percent full under the city’s old bypass procedures. It would have been 85 percent full under the new interim plan.
Galbraith cautioned that the reservoir is “not in happy condition” amidst an unusually dry rainy season. It was at only 58.9 percent of full capacity as of Monday.
Any rain that falls after April 15 can’t be stored in the reservoir, so if it doesn’t come close to spilling by then this could be a difficult year. Galbraith said the technical studies need to examine how the additional bypass would affect the city’s water supply during drought years when the reservoir doesn’t fill, such as 2007.
For about 20 years, the city was taking about 1,500-1,600 acre-feet (one acre-foot is about 326,000 gallons) from Bell Canyon, Galbraith said. When city officials realized in the late 2000s that the city wasn’t complying with the terms of its permit, that number went down to about 1,000 acre-feet.
The city’s 600 acre-foot Napa water contract “basically replaced the water that we used to take from Bell Canyon until we came into compliance with our state permits,” Galbraith said.
“That’s a heck of a hit we’ve already taken to Bell Canyon, and I just don’t see that the city can risk any further material hit to Bell Canyon without significant interruption of economic life here in St. Helena,” he said.
The expenditures approved Tuesday were already included in the city’s Capital Improvement Budget.