FAIRFIELD — California’s $24 billion plan to build two 35-mile tunnels for Delta water exports could hit home in Solano County, from making Suisun Marsh saltier to making local drinking water more costly to treat.
For that matter, though it’s a long shot, Solano County could even be home to the tunnels. One of three possible routes goes through the eastern county near Rio Vista and covers a section of Ryer Island farmland with muck pits.
California has released 20,000 pages of what it calls a “preliminary draft” Bay Delta Conservation Plan. Several local officials said they have yet to read through this massive output – itself one of many state Delta documents – though they are monitoring the state’s Delta plans in general.
“If we mess this up, I think we’ve changed the Delta for centuries to come,” Solano County Supervisor Skip Thomson said. “We have to be right on if we’re moving forward with anything.”
The Sacramento San Joaquin Delta covers 738,000 acres – more than 1,000 square miles – including 86,000 acres in eastern Solano County. It’s a vast network of sloughs and waterways fed by the Sacramento and San Joaquin rivers with Sierra Nevada runoff.
In its natural state, the Delta was a vast holding area for fresh water waiting its turn to squeeze through the Carquinez Strait into San Pablo and San Francisco bays and through the Golden Gate out to sea. Today, California pumps out much of this water to irrigate Central Valley farms and provide drinking water for 25 million residents.
But allowing water to flow through the Delta and then pumping it out from the south Delta near Tracy has caused environmental problems. The pumps suck up and kill rare fish and alter natural water flows. Court decisions have limited water exports to help save the fish, causing consternation among Central California agricultural water users and Southern California municipal water users.
Those twin tunnels are the backbone of the proposed solution backed by the Gov. Jerry Brown’s administration. The state proposes to pump water out of the Sacramento River before it enters the Delta and ship it under the Delta in two, 40-foot diameter tunnels.
Another Bay Delta Conservation Plan component is to restore thousands of acres of tidal wetlands in an attempt to help the rare Delta smelt and other endangered fish.
Any big water plan these days requires a big environmental impact report. Those 20,000 pages of the “preliminary draft” Bay Delta Conservation Plan are to ultimately serve that purpose. The plan looks at three possible water conveyance routes and variables such as amount of water exported, for a total of 15 alternatives.
Solano County officials are trying to figure out what the Bay Delta Conservation Plan and its proposal to reshape the Delta means for Solano County residents.
Building the water conveyance facilities on the western side of the Delta would make it pass through part of eastern Solano County.
That’s not the state’s first choice. California wants to build the twin tunnels miles away from Solano County. But the western alignment remains among the Bay Delta Conservation Plan alternatives.
“There hasn’t been much evaluation of that alternative, because no one is really taking that alternative seriously,” Solano County Water Agency General Manager David Okita said. “They are really looking at the main tunnels down the middle of the Delta.”
Thomson had a similar reaction. He too hasn’t heard any serious discussion of the western option, he said.
State environmental laws dictate that the study must look at a wide range of alternatives, Okita said. Both Okita and Thomson said they believe that is what’s going on with the western alignment option.
It may end up being a mere planning exercise, but the western Delta alignment through eastern Solano County still gets hundreds of pages devoted to it in the Bay Delta Conservation Plan.
Ryer Island would see the biggest effects in Solano County under the western route. The island has corn, wheat, alfalfa, grapes and other crops, with levees holding back the waters of Steamboat and Miner sloughs. It is north of Rio Vista and can be reached using the Real McCoy II ferry.
The state’s water conveyance facility would be a canal as it crosses Ryer Island. It would become two 33-foot-diameter tunnels on the southern island and continue for 17 miles to Hotchkiss Tract near Oakley in Contra Costa County.
A section of Ryer Island would be used to store what the study calls “muck” dug out to create space for the twin tunnels. Tunnel muck is to be less than 25 feet in depth and have dikes around it. Ultimately, the muck could be used for levees or covered with top soil and seeded.
Building the western alignment would cause obstructions in local Delta waterways for up to five years that in some cases would delay recreational boaters. Barges used in construction would at times be in their way.
For example, a barge facility would be built along the Sacramento River about a half-mile east of Cache Slough. Peak boat traffic is high there, in part because Rio Vista and its two boat launches and marina are two miles downstream, the study said.
One way to compensate for these effects on Delta recreation is to contribute money to local Delta recreation projects, the study said. It proposes establishing a new state park at Barker Slough in eastern Solano County.
Building the twin tunnels miles from Solano County along the state’s preferred mid-Delta route could also cause ripple effects in Solano County. Those anticipated changes are documented in the preliminary draft Bay Delta Conservation Plan.
Fairfield and Vacaville are among the local cities that get a portion of their drinking water from the Delta. They use the state’s North Bay Aqueduct system that pumps water out of Barker Slough near Highway 113 in eastern Solano County and takes it to the North Bay Regional Water Treatment Plant near Peabody Road.
One possible change with the twin tunnel system is higher bromide levels at Barker Slough. Bromide levels could increase 40 percent to 98 percent during drought. That could necessitate “considerable water treatment plant upgrades” to meet state and federal water standards, the study said.
“It’s a big concern,” Okita said.
Bromide is associated with salinity from sea water. It reacts with chemicals during the water disinfection process to form brominated trihalomethanes, which studies have linked to tumors and other health problems.
“If you throw enough money at it, you can treat it,” Okita.
The Solano County Water Agency would prefer to move the North Bay Aqueduct pumps far away from Barker Slough, to the Sacramento River near Sacramento. That would get the pumps away from the Delta and problems beyond bromide, among them poor water quality due to organic materials. The cost could be $400 million to $500 million.
The draft preliminary study said Bay Delta Conservation Plan proponents could help pay the costs associated with the North Bay Aqueduct relocation. Other options mentioned are finding alternative water sources for the area and paying for increased treatment costs for the present North Bay Aqueduct site at Barker Slough.
These “proponents” as described in the study are the state Department of Water Resources and various public water agencies, including the Metropolitan Water District of Southern California, Westlands Water District in the Central San Joaquin Valley and Santa Clara Valley Water District.
Okita said the Solano County Water Agency would want a binding agreement upfront to deal with the potential bromide problem. The agency has been asking the state to pay half of the North Bay Aqueduct relocation costs.
“We’re going to start talking to the BDCP and the contractors about this right away,” Okita said. “There is time to negotiate something. I’m sure others like the Contra Costa Water District and maybe Stockton will be doing the same thing.”
Suisun Marsh is about 180 square miles of sloughs, marshes and upland hills south of Suisun City. It is home to duck clubs and state wildlife preserves and is the largest contiguous estuarine marsh in the United States.
Water is the lifeblood of the marsh. Marsh sloughs have a brackish mixture of fresh water draining from the Delta and salt water pushing up from the ocean.
The mixture could be saltier in the late fall and winter under the proposed twin tunnel water export regimen, according to the preliminary draft study. Modeling shows salinity levels could double, though salinity changes would not be uniform throughout the marsh, it said.
Some studies show the marsh in its historic state had greater salinity swings than today. That’s because less fresh water ran down the Delta during the late fall after the dry weather of summer, allowing more sea water to intrude. Today’s massive reservoirs upstream of the Delta didn’t exist to manipulate water flows.
But Steve Chappell, executive director of the Suisun Resource Conservation District, said the flip side of this is the marsh historically saw much greater influxes of fresh water in the spring. Those upstream reservoirs didn’t exist to capture large portions of this runoff for exports to cities and farms.
“My fear is the average salinity in the marsh will end up being higher because we’ll never see the (spring) freshening occurring as quickly as it did historically or for the same duration,” Chappell said.
The preliminary draft Bay Delta Conservation Plan sees little problem with a saltier marsh in the late fall and winter. The Western pond turtle wouldn’t like the saltier water in marsh sloughs, but during the winter could be in adjacent uplands or ditches with lower salinity levels, it said.
With planned tidal wetlands habitat restoration in the marsh, such species as the rare salt marsh harvest mouse and California clapper rail should do well, the draft Bay Delta Conservation Plan said.
Chappell said that, as salinity goes up, most wetlands become less productive and diverse.
Local officials have only begun to look at the 20,000 pages of the preliminary draft Bay Delta Conservation Plan. They have only begun to sort out what the effects might be for Solano County, for good or for bad.
They have time. The release of the draft Bay Delta Conservation Plan – as opposed to the preliminary draft – is scheduled for Oct. 1. It is to be followed by workshops and public hearings.
Then comes one of the biggest “ifs” of all – whether the twin tunnels project will ever get built.
Reach Barry Eberling at 427-6929 or email@example.com. Follow him on Twitter at www.twitter.com/beberlingdr.
Sacramento San Joaquin Delta
Source: Delta Protection Commission