The proposed water pipeline across the Richmond-San Rafael Bridge will undergo standard environmental review, losing its emergency exemption after recent rains spared Marin County from the harshest impacts of the drought and assuaged the urgency of the project. 

Marin Water, which had planned to start construction on the pipeline next month, will soon begin a review of the project under the California Environmental Quality Act. It says the project will give the county’s largely self-contained water systems more flexibility in the long term. 

“We know there’s no longer that imminent threat, and so we can really focus on making sure we’re resilient for future droughts,” said Adriane Mertens, a spokeswoman for Marin Water. “We have the ability now to slow down, do that full environmental review, and look at this as an option.” 

Until now, the district had contended the drought emergency made it necessary to remove regulatory hurdles for the project, which would allow the district to purchase water from third parties and pump it into Marin by way of the East Bay. The district was negotiating a deal to purchase at least 10,000 acre-feet of water from the Yuba County Water Agency, which would be pumped nearly 100 miles from the New Bullards Bar Reservoir in the Sierra foothills to communities in the Bay Area. Smaller utilities like the Inverness Public Utility District had asked Marin Water for an agreement to buy a fraction of the pipeline water. 

Ms. Mertens said the decision to pursue an environmental review was not motivated by a lawsuit filed last month by the North Coast Rivers Alliance, which asked Marin County Superior Court to halt the project until the water district completed a CEQA review that ensured there would be no negative impacts on fisheries. The suit is pending, but the district believes it is now moot, and said the alliance should drop the action. 

Yet Frank Egger, the executive director of the alliance, said the process wasn’t over, despite the district’s decision. “The lawsuit’s been filed, and the courts are going to hear it,” Mr. Egger said. “I’m sure [Marin Water] would like to shortcut it, but they’re the ones that triggered the whole thing.”

Mr. Egger said he was sure the district’s move was a response to his lawsuit. “Everyone’s known all along that we need an E.I.R. and we need to know the impacts on the fisheries,” he said. “They did none of that until the litigation was filed, but they’re posturing themselves as if the lawsuit had nothing to do with their decision.”

The alliance’s lawsuit alleges that the Sacramento-San Joaquin Delta’s tributary reservoirs are suffering more severe shortages than Marin, and that diverting Yuba County’s water would harm local fisheries connected to the Delta. The alliance also raised a concern that in the long term, Marin could use the pipeline in reverse to export water from the Russian and Eel Rivers in the north to Central and Southern California, which could hurt salmonids spawning in those rivers. The district said it was not considering exporting water. 

Mr. Egger, who formerly served as mayor of Fairfax and then as board president of the Ross Valley Sanitary District, is not the only community leader to object to the proposed pipeline. Richmond Mayor Tom Butt said residents of the Point Richmond neighborhood would suffer from air and noise pollution caused by the proposed pump station on the eastern end of the pipeline. 

“Richmond is expected to suffer the consequences of poor planning and lack of water conservation by the 14th richest county in America,” Mayor Butt wrote in a newsletter in October. 

Addressing Mayor Butt’s concerns, Ms. Mertens said the CEQA process would give all interested parties a chance for input on the pipeline. “[There] is definitely a benefit to not being in the emergency that we were in before,” she said. “We can have those conversations with stakeholders.” 

After three months of rains, Marin’s reservoirs are well above normal capacity for January. The network of reservoirs around Mount Tamalpais is spilling at full capacity; Nicasio Reservoir is above 90 percent and Soulajule Reservoir is above 80 percent. Marin Water tapped into Soulajule in early summer for the first time since the 1990s. 

The drought isn’t over, and as recently as this month, the state passed new regulations banning certain outdoor uses of potable water. But Marin Water’s decision to pursue a full environmental review is part of a recent easing of emergency measures undertaken by local agencies last year. 

In November, the Bolinas Community Public Utility District suspended its mandatory water rationing ordinance after the early rains filled up Arroyo Hondo Creek and the town’s two reservoirs. Inverness will consider canceling its water shortage emergency if rain patterns remain normal through February. 

Emergency programs that allowed the county to buy water from Marin Water and North Marin Water District and sell it to ranchers and property owners are not being used for the time being. Roughly 30 agricultural producers were drawing water from Nicasio Reservoir and Stafford Lake in the fall and storing it in tanks, and in October the county opened the option to well-dependent residential properties in West Marin. As of Jan. 1, no ranchers in Marin are drawing any district water, and none of the homes on wells ever had to truck in water through the program.

“It was nice to have that safety net available,” county agricultural commissioner Stefan Parnay said. “The October rains averted the need for that program, but just like agriculture, if things get worse again, we’re ready.” 

The winter rains have also contributed to an unusually strong salmonid spawning season in Marin’s streams. Surveyors with the National Park Service and Marin Water spotted adult Chinook salmon in Redwood Creek for the first time in 20 years and, for the first time, four species of salmon in a single day on Lagunitas Creek. 

The nonprofit Salmon Protection and Watershed Network reported sightings of coho salmon in many small San Geronimo Valley tributaries for the first time in over a decade, and Chinook salmon in Woodacre Creek for the first time ever.