Water in, water out

The sandbar at Jenner was breached Monday to relieve a backup in the lagoon that threatened low-lying homes, at the same time allowing Chinook salmon and steelhead into the Russian River for the fall spawning run.

“We are concerned about eventually flooding, there is more flow in the river than in the summertime because of tributary inflow, the change of the season, and it is time for the fish to access the river,” said Dave Manning, Sonoma County Water Agency principal environmental specialist.

It is the third time this month the Sonoma County Water Agency has breached the mouth to prevent flooding.

Workers first used an excavator to open the sandbar on Oct. 5, allowing hundreds of fish in before large ocean swells built the sandbar back up and closed the mouth two weeks later.

It was breached Oct. 16 and again on Monday, said Jessica Martini-Lamb, a Water Agency biologist.

Manually breaching the sandbar has been practiced for decades. But Martini-Lamb said a new channel has been designed for next year to let high water drain naturally.

At the same time, the shallow channel will limit saltwater flows into the lagoon and improve the water quality for young steelhead migrating to the sea each spring.

“We are trying to create this habitat for steelhead in the first year of life, when they are not able to deal with brackish water or the saltwater that comes in,” Manning said.

If it wasn't for the homes and buildings that line the Russian River near the mouth, the river would be allowed to back up until it naturally breached the sandbar.

The change on how the lagoon is operated is being mandated by the National Marine Fisheries as part of new rules meant to protect endangered coho and threatened Chinook and steelhead in the Russian River and its tributaries.

The far-reaching rules were imposed a year ago by the federal government under the Endangered Species Act and are expected to cost $100 million to meet over the next 15 years to help the fish and continue to provide water to thousands of area residents.

It is not clear who will pay that cost, but Water Agency officials said that part of it will be federal funds, since the federal government owns Warm Springs Dam and Lake Sonoma and operates a fish hatchery there.

The rules affect flows in Dry Creek and other parts of the Russian River and changes at the agency's pumping facilities near Forestville.

It will dictate “how we will continue to supply our contractors, the people who live in Sonoma and Main counties. It is our master plan,” said Ann Dubia, a spokeswoman for the Sonoma County Water Agency.

An update of the past year and future plans are being presented to a committee made up of Water Agency, Army Corps of Engineers, National Marine Fisheries and state Department of Fish and Game officials.

The meeting is from 1 to 3 up.am. Thursday in the Sonoma County supervisors chambers at the administration center in Santa Rosa.

The new federal rules, which could entail the building of a costly pipeline to Lake Sonoma to bypass Dry Creek, is also part of the reason that the Water Agency has dropped a plan to seek rights to 101,000 acre-feet of water.

It now has the rights to 75,000 acre-feet, which is still a third more than it now delivers to its customers.

Since the rules were implemented a year ago, a dozen studies have been conducted on water quality and fish populations in Dry Creek and the Russian River and engineers have begun looking at ways to improve habitat.

At Jenner, a wide, shallow channel will be excavated that will allow the lagoon to drain during high water, but limit the amount of saltwater that flows back in.

Manning said the agency may still need to occasionally breach the sandbar for flood control and for the spring out-migration of steelhead or the fall in-migration of steelhead and salmon.

“It is likely there may have to be some sort of a breach towards this time of year,” Manning said. “The same thing applies to juvenile fish. Theoretically they should be able to swim through this channel, but we will have to see how it performs.”

The rules also affect the release of water into Dry Creek from Lake Sonoma, the Water Agency's major source of water for the 600,000 residents from Windsor to San Rafael.

The federal order requires the Water Agency to improve the habitat of Dry Creek, where fast-moving water now inhibits the spawning of coho salmon, which are on the federal endangered list.

The Water Agency believes that creating pockets of slow-moving water by installing rock and log barriers will protect the fish while allowing flows necessary to deliver enough water to the cities and water districts it serves.

If that doesn't work, the Water Agency in 2018 may have to bypass Dry Creek with a pipeline from Lake Sonoma to the Forestville pumping facilities, which could cost as much as $500 million.

On the Russian River near Forestville, where the Water Agency erects a rubber dam and has its pumping operations, two filtration ponds will be filled in and the fish ladders and screens will be replaced.