A draft biodiversity and vegetation management plan that will guide the management of 16,000 acres of county open space was unveiled on Tuesday at a joint meeting of the Board of Supervisors and the Open Space District board amid concerns over its approach to fire fuel
The district argued that the current heavy-handed emphasis on fuel breaks, or areas in which vegetation is cleared to slow the spread of fire, has eaten up staff time and money. And it is not only inefficient, spokesmen said: the clearing of native vegetation leaves an open invitation to invasive Scotch broom, a fire fuel that can quickly become deeply entrenched. The consuming task of removing broom has also prevented the district from focusing on other work, such as maintaining forest health and fostering biodiversity.
The new plan, which was developed with public input over three years, would limit fuel breaks to priority locations and promote defensible space zones on the borders of urban areas.
Parks manager Linda Dahl defended it on Tuesday. “It’s been portrayed in a way that is misleading, and it’s been portrayed as a new fire plan,” she said, explaining that it would work in concert with the county fire plan, rather than replace it. In response to allegations that the plan prioritizes wildlife and vegetation over fire prevention, she said, “Public safety predominates any other consideration.”
The Open Space District was established in 1972 by popular vote primarily to acquire and manage lands considered environmentally significant, many of which were previously ranches and farms, Ms. Dahl said.
Today, these lands sit adjacent to 3,200 backyards, have about 300 entrances and welcome six million visitors a year, 90 percent of which are Marin residents. The areas also contain 37 special status plants, 11 special status wildlife species and nine plants that are found only in Marin.
Fire Chief Jason Weber said that the fire department has been working with the Open Space District on the plan. “By no means is fire protection going to be sacrificed,” he said at the meeting.
Ms. Dahl addressed questions about the July 4 fire on Mount Tamalpais, which fire officials at the time said could have been devastating had it not been for fuel breaks that helped stem its spread. “That area would have been cleared under the new plan,” she said.
There are currently 500 acres of fuel breaks on open space land, compared to just 100 acres before 1994. The Mount Tam event demonstrated that “fire burned with considerably less force on the side that was treated [with fuel breaks],” Marin Fire Chief Jason Weber told the Light.
But Ms. Dahl argued that a laser focus on fuel breaks allows invasive fire fuel like broom to thrive.
“What this allowed the weeds to do was to come in without competition,” said another panelist who helped develop the draft plan, adding that broom is incredibly difficult to permanently eliminate due to the fact that seeds can remain active in the soil for decades.
In 2012, the district spent 20 percent of its budget, or $1.3 million, on broom eradication. “All they were doing was broom—chasing broom, chasing broom,” Ms. Dahl said of the staff. It was inefficient and not adaptive, she argued, as the district had no time to protect habitats before they were invaded.
Another member of the panel who has worked in fire prevention for decades said that not only are fuel breaks inefficient but they do not always work in worst-case scenarios. “Unfortunately, the fuel breaks helped in low intensity [situations] or moderate sometimes, but in high intensity fire behavior... those fuel breaks didn’t do any good. The fire burned across those things like they weren’t even there,” said Dave Bacon, now a private fire prevention consultant of his observations over time.
Chief Weber said such scenarios were more likely in large-scale fires, such as ones in southern California, and weren’t necessarily applicable in Marin because open space lands are fairly small.
Mr. Bacon said that the most current science on fire prevention and fuel management calls for a focus on strategic fuel breaks and defensible space zones at the interface between urban areas and
The plan does not provide prescriptive measures, but rather basic guidelines for how to make decisions for open space lands. “The program that we developed is not prescriptive but rather is a system for making decisions in a consistent manner,” said Loran May, a long-time botanist and head of May and Associates, which drew up the draft plan.
One of the ways it does that is establishing a system for collaborative assessment of future projects in which the Open Space District, the fire department, local jurisdictions or other parties could rank potential projects on different scales—impacts on habitat and public safety, for instance. That input could be submitted to the Marin County Department of Parks, which on a yearly basis prioritizes promising projects for funding.
Project panelists said the collaborative process would collect expertise from multiple entities, and viewed it as a strength. But some supervisors expressed concern over the feasibility of the so-called matrix of decision-making, wondering whether what sounds ideal in theory would work in practice.
Ms. Dahl noted that the Open Space District planned to run through both an “easy project” and a “difficult project” to evaluate the system as part of the plan’s final draft.
“I can see you having three representatives of three agencies and they’re rankings are all different,” Supervisor Kathrin Sears said. “So road testing is going to be incredibly important to see if you need to fine tune to see if this system works.”