Where the Tides Have Returned

With a high-pressure system parked over the Pacific Ocean and a tenacious fogbank blanketing the San Francisco Bay region in mid-December, Dave and I drive through farmland in eastern Solano County, our silver Coleman canoe strapped to the top of the truck.

Our destination is the 3,400-acre Lookout Slough, the largest tidal wetland restoration project in the Sacramento–San Joaquin Delta and in state history. The $130 million project was designed to enhance fish and wildlife habitat while increasing floodwater capacity of the Yolo Bypass as sea level rises. It also provides 26 miles of new tidal channels. Completed in September 2024 by the California Department of Water Resources (DWR) and Ecosystem Investment Partners, it’s part of a larger effort by DWR to restore 16,000 acres in the North Delta. 

From the parking lot at the end of Liberty Island Road, we roll the canoe cart over a new levee and down 250 yards to a boat ramp, where a view of Mount Diablo would be visible on a clear day. As we launch against a flood tide, a great blue heron takes off from a tree and a belted kingfisher flies overhead. Soon, the only sound is our paddles dipping in the water. 

We decide to explore Shag Slough, a straight channel about 200 feet wide that flanks the eastern boundary of the restoration project. On Shag Slough’s western side, an old levee built more than 100 years ago converted these wetlands into pasture. For decades, this site was used for grazing, as well as hunting by a private duck club, but returned to wetlands after DWR breached the old levee in nine locations, letting the tides flow in and out of newly engineered sloughs. Hunting and fishing are now accessible to the public, and occasional gunfire may be heard, particularly during waterfowl hunting season (October through January).

“We’re reestablishing natural processes that have been disconnected for over 100 years,” Charlotte Biggs, an assistant deputy director at DWR, explained in an email. “A century ago landowners had certain priorities in mind, and I think today we’re striking a new balance. Seeing projects like this get built and be part of the mosaic of the Delta is going to help us better manage the overall area and make it more sustainable.”

The nine breaches have signs indicating the names and lengths of the sloughs, which range from 990 feet to over three miles. The first breach near the boat ramp opens to Biggs Slough, the shortest of the newly made sloughs. Although the second breach, Irving Slough, beckons with its sinuous banks of sedge and cattails, we paddle past it and the third and fourth breaches. 

Just north of a small concrete bridge, about 50 birds flit about the branches of native willow, white alder, and Fremont cottonwood trees. My Merlin Bird ID records five kinds of sparrows, as well as orange-crowned warblers and ruby-crowned kinglets.

The tidal range in the Lookout Slough  area can differ by six feet, and we avoid the areas where the flood is gaining momentum and pouring into the fifth and sixth breaches. Near the seventh breach, a large California sea lion cheekily searches for fish.

This project was designed to restore habitat for Delta smelt and other threatened and endangered pelagic fish—those that inhabit the sweet spot of a channel, not at the bottom or close to shore. Lookout Slough is part of a biologically important area called the North Delta Arc, a fishhook-shaped region that includes Suisun Marsh, the Cache–Lindsey Complex, the Yolo Bypass, and the lower Sacramento River. It’s a critical area for conservation that’s being studied by the North Delta Arc of Native Fishes project at UC Davis. 

Although the Arc project’s 2025 report was not ready for publication as of this writing, field-sampling lead Mason Rogers says his team found pelagic species such as striped bass, threadfin, and American shad in their trawls during high water flows in early 2025—a promising sign given that pelagic fish are in decline throughout the Delta.

But by summer, researchers only rarely trawled up pelagic species like they had in the winter. Rogers believes that low plankton levels are to blame. “With the tide, the channels take on water very quickly and export water very quickly,” he says. This leaves plankton little time to populate. And aquatic weeds that filter out phytoplankton and zooplankton—food for pelagic fish—are moving into the south channels. UC Davis is collaborating with DWR and the California State Parks Division of Boating and Waterways to evaluate the effectiveness of weed control measures.

Still, the researchers were pleased in spring 2025 when seines turned up migrating juvenile Sacramento splittail, a native fish that the team has rarely found in the area, according to John Durand, senior researcher with UC Davis’s Center for Watershed Sciences. Although the splittail are not pelagic (they hug the channels), their presence represents habitat connectivity. “These juveniles were probably coming from their natal sites on the Yolo Bypass,” noted Durand in an email, “or maybe within the restoration, on their way down to Suisun Marsh’s vicinity, where the adults are commonly found.” 

Shag Slough spreads into a larger waterway around the eighth breach. At the ninth breach, near the southern end of the Yolo Bypass, we land on a patch of shore to stretch our legs and eat a sandwich in the pluff mud, otherwise known as suck mud. Five trumpeter swans fly overhead, their wings gently whooshing.

On our return trip, the end of the flood tide helps us paddle against a moderate headwind. Six river otters travel southbound on the tide that has turned to an ebb. 

Two weeks later, on the advice of DWR’s Biggs, we return to paddle Irving Slough. “It’s one-quarter mile south of the boat ramp and is representative of all the sloughs and is well vegetated and goes the full length of the project,” she says by email, also reminding me to look for river otters, beavers, mink, and occasional seals.

The sun is a white ball behind tule fog as we enter the wide, peaceful channel of Irving Slough. In the marsh to our left, unseen greater white-fronted geese and marsh wrens make a ruckus. Cows moo from a nearby field.

After passing below high transmission lines, we stay to the left at a split. Normally a slough narrows at its top, but this one spreads into a large body of water. “The upland (west sides) of the channels seem to spread out into a very shallow tidal plain—not sure that we know what to think of that as habitat just yet,” Durand wrote in an email.

On our way back, the fog breaks up to reveal blue skies. Near the boat ramp, a harbor seal enters the first slough and three American white pelicans fly overhead. 

After two visits I have grown fond of this place and plan to come back when it’s warmer. In spring, vibrant blades of sedge will emerge, and even when the surrounding fields and distant hills desiccate, the marsh will be green all summer.

EXPLORE

Lookout Slough

• The draw: The largest tidal wetland restoration project in the history of the Sacramento–San Joaquin Delta. 
• Water trails: Twenty-six miles of sloughs explorable by nonmotorized, hand-launched boat.
• Tide Station: Use the Rio Vista station to check for tides. It’s best to explore the sloughs during a high tide, or close to it.
• Facilities: No restrooms or picnic benches.
• Getting there: A parking lot is available at the end of Liberty Island Road, Solano County. The coordinates (linked here to a Google Maps location) are 38°19’44.4” N, 121°41’40.1” W.