In a quiet corner of Napa County, tucked away in the hills above its famous valley, a bucolic trickle of a creek is now flowing free after languishing behind a dam for more than a century.
The waters of York Creek began their unabated journey to the Napa River on Sept. 14 for the first time since the latter part of the 1800s, when they were corralled in order to irrigate thirsty vineyards and provide drinking water to the little town of St. Helena about 1.5 miles downstream.
Now, after 27 years of starts and stops, a lawsuit brought by state regulators, a court order, a long-running federal fine and the threat of further legal action from environmentalists, the old earthen dam is finally being removed in order to restore a portion of the creek to a more natural state.
The goal is to encourage the comeback of its original inhabitants, including a threatened steelhead trout population (Oncorhynchus mykiss) that once spawned in the waters of its shady upper reaches.
“It’s still fairly unique within the state of California to remove any dam,” said Ted Frink, chief of the Special Restoration Initiatives branch at the California Department of Water Resources.
“It’s always more complicated than anyone can imagine,” said Frink, who was involved in one of the project’s early planning stages.
For generations, dams have been as much a part of the California landscape as the rivers themselves and are an integral part of the state’s byzantine water supply and flood control systems.
Over the past 30 years, more than 100 small dams have been demolished in California, but roughly 1,500 still stand, according to a 2019 report by the Public Policy Institute of California.
“The public gets very comfortable with the idea that the dams are going to be there forever,” Frink said.
While environmental studies conducted by the city of St. Helena identify 1900 as the year the York Creek dam was built, the late wine historian William Heintz says in his 1991 report “Napa Valley’s ‘Spring Mountain’ Appellation” that it was constructed years earlier.
Heintz says it was described in an August 1878 edition of the St. Helena Star newspaper as a 24-foot-high, 225-foot-long dam built by a water company led by John York, Charles Krug, Jacob Beringer, Seneca Ewer and G.K. Gluyas.
“It goes to the very essence of the very beginning of the wine industries,” said William McKinnon of Water Audit California, which threatened legal action over the stalled project.
When a dam is demolished it’s usually due to concerns about earthquake safety or environmental protection or because the dam itself no longer serves its original purpose – like when a reservoir fills with sediment and loses water storage capacity.
The process to remove the York Creek dam started back in the summer of 1992 – 60 or 70 years after the city stopped using it as a primary water source – when a crew was doing some routine maintenance work that led to “an accidental discharge of sediment,” according to an environmental impact report commissioned by the city.
The sediment had been building up behind the dam for decades at the rate of between 1,000 to 5,000 cubic yards per year and when released, it left silt deposits of up to 18 inches deep just below the dam.
By the time those deposits traveled the roughly three miles downstream to the confluence of York Creek and the Napa River, they had thinned to a dusting of fine silt, but by that point the damage was done.
It was the fourth such catastrophic discharge from the dam since 1962, and it killed an untold number of fish and other aquatic creatures.
In 1993, after lawyers with the California Department of Fish and Game filed a complaint with the Napa County District Attorney’s Office, a Superior Court judge in Napa ordered the city to remove the dam.
In a settlement agreement, the city also committed to removing the silt and preserving “the stability and natural character of the area,” according to the EIR.
The court order was rescinded in 2001 so the project would be eligible for grant dollars, and momentum really started to build in 2012 when the city was able to acquire grants from the U.S. Environmental Protection Agency and state Proposition 84 for nearly $2 million, said St. Helena’s Public Works Director Erica Ahmann Smithies.
As an additional incentive, the National Oceanic and Atmospheric Administration (NOAA) had been fining St. Helena $70 a day since 2012 – to the tune of about $190,000 – over its failure to get moving on the project.
Also, Water Audit California threatened to sue St. Helena in 2016 over the ongoing damage to fish populations.
McKinnon of Water Audit California said the project’s fitful history is due to “grotesquely incompetent civic management.”
“The threat of litigation combined with a nominal change in (St. Helena’s) civic leadership that is more inclined to resolution than control led to the project being built,” McKinnon said.
On Sept. 4, NOAA said in a letter that it was suspending the penalties because of the city’s recent progress on removing the dam.
From its inception, the project was beset by a variety of delay-inducing hurdles, including changes of political leadership at the mayoral, city council and planning commission levels, the departure of key city staff and consultants, other large municipal projects that seemed to take priority and the need to secure approval from a mind-boggling array of local, state and federal regulatory agencies.
In addition, the Great Recession of 2008 and 2009 hampered the city’s ability to secure grant dollars to help pay for the roughly $8.8 million project, said Smithies, who came to work for the city in 2016.
Smithies likened the complex environmental review and planning process to “herding cats” and said it’s been “one step forward and two steps back” for years.
“It’s an exciting project that’s taken way too long to happen,” Smithies said. “It’s been crazy.”
The current mayor, Geoff Ellsworth, his predecessor and the last couple of city councils set their sights on removing the dam and restoring York Creek, she said.
“This has been a priority but the funding just wasn’t there,” Smithies said. “Trying to get this project across the finish line has been difficult and it’s been costly.”
The city finalized the environmental impact report for the “Upper York Creek Ecosystem Restoration” project in 2015 and accepted the final plan design in June 2020 after multiple revisions.
By then, it had most of the required permits in hand and a contractor in place and ready to start working.
“It’s been a masterpiece of putting this project together,” Smithies said.
Mayor Ellsworth, who was born and raised in the picturesque little valley town, said that since the city stopped using the reservoir, the dam and its problems were sort of “out of sight, out of mind.”
“The struggle has been getting everything to line up, and it goes back to a group of people keeping an eye on the ball and looking for the timing windows to make it work and then making it a priority,” Ellsworth said.
“If the political will lines up and makes it a priority, you can move these things forward,” he said.
The project itself presented several technical challenges, including whether to demolish the entire dam, partially remove the dam or partially remove the dam and build a fish ladder.
It was eventually decided that the best course of action was to cut a V-shaped “notch” in part of the dam, leaving the adjacent concrete spillway intact since it also serves as a buttress for a short stretch of Spring Mountain Road, which runs parallel to York Creek as it winds its way into town.
Before carving out the notch, however, crews had to remove the built-up sediment, 10,000 cubic yards of which were dredged out and trucked to the nearby Spring Mountain Winery in 2006 or 2007.
An additional 12,000 cubic yards of sediment and 10,000 cubic yards of soil from the dam itself also had to be removed, but this time were hauled eight-and-a-half miles away to the Clover Flat Landfill, as well as to a couple of fire restoration projects in Napa County.
Final removal of sediment and soil from the dam wrapped up before Labor Day and resulted in up to 100 daily truckloads of soil and debris rumbling through the streets of St. Helena and up state Highway 29 to the landfill.
During this part of the project, the stream was being diverted – pumped through a pipe that runs up the creek bank and along Spring Mountain Road, down the old concrete spillway and back into the creek just below the dam.
Crews are now working to place up to 36 “sediment traps” in the lower portion of the creek in order both to moderate the distribution of silt downstream now that the dam is gone and to create new habitat for the steelhead.
The traps will be placed in the streambed at strategic intervals and will be made from logs taken from two fir trees and seven redwoods that were growing on or around the dam, as well as some trees felled at Spring Mountain Winery, Smithies said.
“The trees will come back, this we know, and will come back fast. The sediment material is very fertile,” she said.
The project is expected to be completed by the end of October and should result in the restoration of about three acres of “degraded riparian and aquatic habitat surrounding the dam and reservoir, including restoration of roughly two acres of native riparian forest,” according to the city’s environmental study.
Additionally, removing the dam and replanting the creek with native flora is expected to help improve the ecological health of the entire Napa Valley.
“Our reasonability to the larger region is to be participants in looking for climate solutions. We’re wanting to be among those going in the right direction environmentally and in terms of climate,” Ellsworth said.
York Creek originates in the hills of the Mayacamas Mountains, which are part of the inner range of the California Coastal Range System and serve as a natural border between Napa and Sonoma counties.
“I thought it was a remarkably beautiful and surprisingly forested and seemingly intact and undisturbed tributary. It was almost surprising to happen across the dam in that forest,” said fisheries biologist Mike Davis, who did some early wildlife assessments for the project.
The creek winds its way south and east through the hills, along Spring Mountain Road and through St. Helena to eventually contribute its water to the Napa River, which flows south to San Pablo Bay.
“York Creek could provide some of the best available spawning and rearing habitat for Central Coast steelhead that can be found in the Napa Valley watershed,” Davis said.
“The numbers of these fish that are left with us today are so small compared to what they once were. They are at threat of being gone forever,” he said. “When I think about all the effort we expend on these tiny creeks or isolated rivers, we are at the beginning of building their return.”
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