Sonoma County’s open space district is nearly 30 years old. What’s in store for the next decade?

Taylor Mountain, rising to more than 1,300 feet at Santa Rosa’s southeast corner, affords panoramic views of the city, grassy hillsides, oak woodlands, creeks and about 6 miles of trails for hikers, bikers and horseback riders.

As a scenic backdrop for the Bay Area’s fifth most populous city, the mountain dominating an 1,100-acre county park qualifies in many ways as an asset: a place to play, to revel in nature and a hedge against the urban sprawl that has overrun much of the region.

So says Bill Keene, head of the public agency that over the past three decades has parlayed nearly $400 million in taxpayer dollars into 118,000 acres of protected open space and farmland, equal to about 12 percent of Sonoma County.

Taylor Mountain Regional Park is a shining example of the payoff the public has received from granting a quarter-cent sales tax to the Sonoma County Agricultural Preservation and Open Space District in 1990, Keene said.

To date, the district, among the first of its kind in California, has spent about $334 million buying development rights and another $65 million on outright land purchases scattered around the county.

“Drive out of town in any direction - you’re looking at land that’s in easements.” Keene said, using the term for the deals meant to permanently stave off development.

And the trend is growing, with the sales tax revenue stream estimated at about $386 million from now until 2031, when the current tax - renewed by a whopping 76% of county voters in 2016 - expires. The district also estimates it can leverage up to $120 million from outside sources. With about $150 million set aside for program costs, the agency estimates it will have up to $350 million for conservation deals through 2031.

The district has drafted a 115-page plan, dubbed the Vital Lands Initiative, documenting its achievements and outlining a land conservation plan for the next 12 years.

“People love open space, parks, trees and water,” said David Rabbitt, chairman of the county Board of Supervisors that also oversees the district. “Those are always going to be at the top of the list of things it’s important to make an investment in.”

Sonoma County “would look a lot different,” he said, without the parks, pastures and viewsheds protected as permanent open space.

Decades ago, when the county looked south to sprawling San Jose, people said “it can’t happen here,” recalled Wendy Eliot, conservation director at Sonoma Land Trust, a Santa Rosa nonprofit that often partners with the open space district. “But it could happen here,” she said, if not for embracing the “radical idea” of devoting taxes to open space protection.

In a county of more than one million acres, the district has helped provide 19,000 acres of open land for recreation, including 37 new parks, preserves and public spaces, 70 miles of trails and an additional 14,000 acres of land in existing state and county parks.

It played a role in protecting more than 62,000 acres of native oak forests, 5,800 acres of wetlands and waterway habitat and 98 miles of creeks that host salmon and trout, 33,000 acres of grazing land and support for 77 agricultural properties producing cheese, milk, meat, poultry, produce and wine that contribute to a $650 million farm economy.

And done it all at a “great value for the dollar,” said Eliot, whose organization has worked with the district on numerous land acquisitions, including Tolay Lake Regional Park near Petaluma.

The district put up $2 million and the land trust used it to leverage an additional $11 million from the state and federal governments and other sources, she said.

For the 5,500-acre Jenner Headlands coastal preserve, the district put up about $9 million and the land trust corralled nearly $27 million more to complete a $36 million land purchase.

In the case of Taylor Mountain the district bought the land outright for about $20 million, then transferred it to the county’s parks department.

On much smaller projects, the district contributed $1.3 million and Santa Rosa put nearly $4 million into the Bayer Neighborhood Park and Gardens, while it split the $1.5 million cost of Windsor’s Town Green evenly with the city.

Bert Whitaker, director of Sonoma County Regional Parks, said district projects doubled the size of system that now totals 13,000 acres and is “part of the daily life of folks who live here.”

Thanks to the wide-ranging conservation purchases, Sonoma County “looks a lot like it did 25 years ago,” he said.

Tawny Tesconi, executive director of the Sonoma County Farm Bureau, reiterated the organization’s long-standing complaint that more open space funds should go to supporting agriculture, especially grazing lands.

Buying property development rights has allowed some longtime ranching families to “stay in business during hard times,” she said.

But Tesconi faulted the 25% share of conservation investments - up to about $90 million over a dozen years - as insufficient.

“We want to see more money go to agricultural preservation,” she said.

The Vital Lands report, scheduled for consideration by the supervisors on Tuesday, includes 11 maps showing priority areas for conservation of farmlands, greenbelts, streams, wetlands, forests, wildlife habitats and other purposes.

Specific parcels are not identified and considerably more evaluation would be needed before any properties were targeted for acquisition, including the question of whether the landowners are “interested in extinguishing certain property rights,” said Karen Gaffney, the district’s conservation planning manager.

Keene, whose goals include tripling the acreage of county parks, said the district will seek voter renewal of the tax well before 2031.

“Everyone should be able to take a 10-minute walk from home and get connected with nature,” he said.

You can reach Staff Writer Guy Kovner at 707-521-5457 or guy.kovner@pressdemocrat.com.