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Too Much Water?

Warm Springs Dam, Lake Sonoma

Lake Sonoma was built to provide water to the North Bay, but federal officials say increased flow could threaten coho salmon.


Sonoma County is drawing too much water out of Lake Sonoma, jeopardizing the recovery of two threatened fish species in a rural creek, federal wildlife officials say.

The finding pits the survival of tiny coho salmon and steelhead in Dry Creek against the needs of 600,000 North Bay customers who depend on the lake’s water.

In the looming showdown, the people likely will spend millions of dollars to continue drinking and irrigating from the lake and using the creek, a critical fish habitat, as an aqueduct.

That’s after spending $360 million three decades ago on Lake Sonoma, the vast reservoir behind Warm Springs Dam near Healdsburg. Nearly brimful with 76 billion gallons of water — a two-year supply despite a dry spring — the lake is fulfilling its dual mission of controlling floods and impounding water along the Russian River system.

In 1983, when the dam was completed, no one dreamed that fish would constrain its water delivery to the 600,000 customers from Windsor to Sausalito.

The situation is “dripping with irony,” said Chris Murray of the Sonoma County Water Agency.

The conflict emerges at an inopportune time for the Water Agency, which is coping with a springtime drought this year and, with an eye on the future, seeking a 35 percent increase in Lake Sonoma water rights to accommodate North Bay growth.

On Sunday, the Water Agency’s call for mandatory water conservation went into effect, aimed at a 15 percent cut in use through Oct. 28. That step, along with curbing summer flows on the Russian River, is intended to compensate for paltry spring rains that left the region low on water for the third time in the past six years.

Other overtures to put more water in the Russian River, such as raising Lake Mendocino’s dam near Ukiah or revising a Potter Valley power plant’s operation, appear to be thwarted or delayed by high costs, bureaucratic delays and a Western water war that dates back to the early 1900s, emblematic of Mark Twain’s observation: “Whisky is for drinking; water is for fighting over.”

With no cheap or immediate relief available to the 750,000 people in Sonoma, Mendocino and Marin counties who draw their water from the river, experts say the low-flow summer of 2007 is a harbinger of the future.

“Better get used to (water) conservation,” said Bill Hearn of the National Marine Fisheries Service office in Santa Rosa. “These are the problems we need to wrestle with.”

The dilemma is, indeed, replete with irony.

Lake Sonoma

Lake Sonoma’s abundant water supply can’t be tapped fast enough to meet summer demand without endangering the federally protected fish in Dry Creek. Meanwhile, Lake Mendocino’s smaller water pool must be gingerly conserved to provide enough river flow for migrating fish in the fall. Aggravating the water woes this year was a rain-scant spring, with precipitation about 50 percent below average, and new limits on the historic diversion of Eel River water into the Russian River.

Sonoma County Supervisor Mike Reilly calls it a “regulatory drought” and is pursuing a larger diversion through the Potter Valley project. Other officials are cool to the idea, and Eel River interests flatly oppose it.

“There is no more water coming out of the Eel River,” said David Keller of Petaluma, Bay Area director for Friends of the Eel River. “That is not going to happen.”

Already, there have been at least two emergencies this year as water managers struggle to meet the growing needs of homes, farms and businesses from Ukiah to Tiburon with an increasingly constrained water supply.

In February, Mendocino County farmers secured a one-time boost in Eel River water to provide a frost-fighting supply for their apple and pear crops.

In May, the county Water Agency won state approval to cut flows in the Russian River, followed by an order two weeks ago for the mandatory water conservation measures starting Sunday.

“It makes for a bizarre situation,” said Murray, the Water Agency’s chief of water resources planning.

The latest constraint stems from a rather unusual conclusion by federal fisheries biologists. Too much water, they say, as opposed to too little, can jeopardize the coho salmon and steelhead that spend the first summer of their lives in Dry Creek.

Every drop the Water Agency draws from the river near Forestville must run down the creek, which flows 14 miles through grape-growing Dry Creek Valley from Warm Springs Dam to the Russian River.

“They are basically treating 14 miles of critical habitat as a conveyor belt,” said Hearn, a supervising biologist for the National Marine Fisheries Service.

Even a relatively low summertime flow, controlled by releases from the dam, is devastating to the fingerling coho salmon and steelhead in Dry Creek, according to fisheries officials, who are discussing the implications with county water managers.

At flows of more than 100 cubic feet a second, typical for summer dam operations, the flow creates havoc for the fish. “It’s like a fire hose. It’s blasting them,” Hearn said.

The National Marine Fisheries Service has circulated a draft version of its Dry Creek flow assessment, called a biological opinion, which is not available to the public but is under discussion by county and state officials.

Murray said the opinion is “truly the basis for the future of the river” and agrees that the status quo will not stand. “It’s time for real change,” Hearn said.

The draft opinion does not stipulate changes, but Hearn said it establishes that flows like last week’s 122-cubic-feet release are untenable. (A cubic foot is 7.5 gallons; minimum flows in the Russian River, under the state-approved summer flow plan, are 75 to 85 cfs.)

To continue using Dry Creek as an aqueduct, the Water Agency must install a pipeline along the creek, reconfigure the creek channel with boulders and logs to create slow-water refuges for the fish, or both. Interagency discussions this summer will determine the specifics, officials said.

Reducing the creek flow to 50 cfs “looks great,” Hearn said. But with sufficient modifications, the channel could handle 150 cfs without harm to the coho and steelhead, he said.

No cost estimates for a creekside pipeline or for channel modifications have been made, Hearn and Murray said.

The county has revived consideration of a pipeline that would parallel Dry Creek to the river or run all the way to the Water Agency intake near Wohler Bridge, a project that would take years and millions of dollars to complete.

Peak water demand at Wohler is 120 cfs, and Murray said the Water Agency, aware of federal concerns, is trying to stay within a self-imposed limit of 90 cfs in Dry Creek, with the balance coming downstream from Lake Mendocino.

The recent 122 cfs release was needed to meet increased demands because of a sudden heat wave, he said.

There is no government mandate on Dry Creek flows, an issue that was unforeseen when Warm Springs Dam was designed and built, with the reservoir more than 20 miles from the county water intake.

The new biological bottleneck on the creek would presumably have to be resolved before Sonoma County could draw an additional 26,000 acre-feet of water from Lake Sonoma, intended to meet growing demand from customers in Sonoma and northern Marin counties.

Murray said it is impossible to tell now how large a flow on Dry Creek would be needed to extract the added water.

“I’d love to be able to go higher than 90” cfs, he said.

Cold water released from the dam is perfect for coho salmon, listed as an endangered species from Santa Cruz to Humboldt County and found in only six tributaries of the Russian River, including Dry Creek.

With suitable flow levels, Dry Creek could be a potent nursery for the once plentiful coho, accounting for 39 percent of its rearing habitat in the Russian River watershed, Hearn said.

But coho and steelhead, the latter a threatened species, are vulnerable to high-velocity water. Both species spawn in Dry Creek, their offspring incubating in the gravel streambed and emerging as small fry from April into early summer.

Coho return to the ocean the following spring; steelhead spend up to three years in the creek. Fast-flowing water literally sweeps away the fingerlings that are only a few inches long, the federal biologists say.