A dense stand of oak trees located across the street from the entrance to Trinchero Winery in St. Helena, California, in 2009. Preserving the valley’s remaining oak woodlands is the subject of a new ballot initiative. (George Rose/Getty Images)
After years of trying to save the oak trees he loves in Napa County, California, Jim Wilson may be about to realize his dream. He’s part of the team behind Napa’s Measure C, an initiative on the June ballot with the twin goals of preserving oak woodlands and protecting water.
“Our hillsides are beautiful and also filter rain, keeping water clean as it replenishes aquifers,” said Wilson, a retired Anheuser-Busch chemist who lives on a fifth-generation cattle ranch in Napa. “Ninety-five percent of oaks on the valley floor are gone and we want to do a better job reducing deforestation on hills.”
According to a 2006 report by the California Oak Foundation, oak woodlands cover about one-eighth of the state and are densest in Napa, covering some 167,000 acres, or one-third of the county. More than 90 percent of Napa’s remaining oak woodlands are privately owned and about one-third are on soil that could be agriculturally productive, according to the 2010 Napa County Voluntary Oak Woodlands Management Plan.
Agriculture covers about one-fifth of the county, and today’s oak woodland loss is primarily due to vineyard development. Napa vineyards covered nearly 50,000 acres in 2006, and the county’s General Plan projects that they will cover another 10,000 acres by 2030. About 3,000 acres of this vineyard expansion is projected to replace woodlands.
Current oak woodland protections include requiring that two replacement oaks be planted or preserved for every mature oak felled. In addition, some oaks on private land are protected now – including those on slopes steeper than 35 percent and in riparian forests along streams – but many are not. So Wilson decided to take matters into his own hands, coauthoring the Napa County Watershed and Oak Woodland Protection Initiative. “Developers wield an awful lot of power,” he said. “They are used to being able to say how we use our natural resources in Napa.”
The initiative’s key provisions include increasing the number of replacement oaks from two to three, and extending riparian protections to the ephemeral streams that are dry most of the year but channel rainfall during storms. Most controversially, beginning in 2030 the initiative would also limit oak removal to 795 acres. After that, landowners would need a county permit to remove more oaks and even then could remove only 10 percent of the oak canopy cover on a given parcel.
The local farm bureau objects most strongly to the initiative’s limit on removing oaks. “Napa County has some of the most stringent oak woodland protections in the country,” said Ryan Klobas, policy director for the Napa County Farm Bureau. “There is no scientific evidence to substantiate claims that the initiative is needed.”
The bureau also believes that the initiative is anti-agriculture. “It narrowly targets vineyard development,” Klobas said. “There are exceptions to the oak removal limit but agriculture is not one of them.”
Exceptions include oak removal to make room for affordable housing and other projects required by state or federal law.
Opponents also cite a legal analysis of the initiative commissioned by the county board of supervisors, which concluded that there is a “significant likelihood” of legal challenges. The analysis, conducted by real estate law firm Miller Starr Regalia, also said that “at least portions of [the initiative] would likely survive any legal challenge.”
Another approach to protecting Napa’s water from vineyard development is already in the works. In 2017, the San Francisco Bay Regional Water Quality Control Board adopted a regulation to control pollutants from vineyards in the Napa River and Sonoma Creek watersheds. Potential pollutants include nutrients from fertilizer as well as pesticides, notably those that mimic estrogen and might have the unintended effect of feminizing salmon.
According to the water board regulation, vineyards are also “significant sources” of sediment, which can cause a host of problems in waterways such as clogging the loose gravel where salmon spawn. Moreover, converting forests to vineyards can “significantly increase” storm runoff and erosion. Under the new regulation, cutting down native trees above a certain size will require approval from the California Department of Fish and Wildlife, as well as planting three replacements for every tree that is cut. The regulation will be phased in over the next five years.
Of course, oak woodlands do far more than protect water quality. Oak canopies capture up to one-third more rainfall than grasslands, boosting groundwater supplies. In addition, oak woodlands are among the most diverse ecosystems in California, with more than 300 animal species, nearly 5,000 insect species and more than 2,000 plant species, according to the San Francisco Estuary Institute. And many of these species depend on oaks.
Charles Slutzkin has what may be an unusual take on the initiative. “I find myself in the awkward position of opposing it, but supporting the preservation of oak woodlands and watersheds,” said Slutzkin, a retired commercial developer who is a longtime Sierra Club member and served on the Napa County Resource Conservation District board for a decade.
He sees initiatives as a failure of governance. “You get them when the political process doesn’t work,” he said. “Supporters of the watershed and oak woodland initiative are well-meaning and the goal is good – but you can’t write a perfect initiative.”
Instead, Slutzkin favors an inclusive process like the one that culminated in Napa’s Living River project, which combines flood control with environmental restoration. “I would like to see the county take leadership as it did with the Living River to create community consensus,” he said.
While the initiative has divided Napa, Slutzkin noted that “there are no bad people on either side.”