As Marin County prepares to enter the most dangerous stretch of fire season, up to 70 percent of residents are not doing enough to protect their homes, according to recent inspections by the Marin Wildfire Prevention Authority. But officials with the M.W.P.A., established last year through a new tax, say their stringent standards are the reason for low compliance rates. 

The wildfire prevention authority has conducted over 25,000 inspections to date this season. The zone that includes the Ross Valley and West Marin has seen almost 10,000. Somewhere between 30 and 50 percent of homes are complying with guidelines.

“I’m not concerned that our numbers aren’t perfect,” said Kathleen Cutter, a fire mitigation specialist who leads the defensible space program. “Overall, we’re doing better and better.”

Inspectors are currently at work in Woodacre, and will be moving through the rest of the San Geronimo Valley in the coming weeks before moving on to Bolinas, Stinson Beach and Muir Beach. They hope to check in on West Marin properties every other year, prioritizing hillside communities and inland valleys that get less moisture from the marine layer.

Voters last year passed Measure C, which created and funded the authority using a new parcel tax. Made up of officials from the Marin County Fire Department and other local fire agencies in the county, the M.W.P.A. has harnessed these funds to ramp up defensible space inspections with a team of seasonal employees. 

Before the authority was established, local engine companies would rotate inspection duty, checking in on each community once every three to four years. 

“It wasn’t consistent,” county fire chief Jason Weber said. “The data we were collecting was minimal, and our impact was certainly not where we needed it.”

During wildfires, falling embers are usually to blame when houses go up in flames, so it’s vital for homeowners to limit the amount of nearby fuel.

“Basically your home is a log. Embers hitting it are probably not going to start it,” Ms. Cutter said. “But you don’t want kindling around the home.” 

Zone zero, which is how fire safety officials refer to the area less than five feet out from the home, should be free of dead bushes, leaf litter and lumber. Garbage and recycling bins should be kept further from the structure. 

Vents on homes should be as small as possible, and gaps in siding should be closed to keep out embers that could make their way into an attic or cellar. Leaf litter should be cleaned out regularly from gutters and rooftops. Homeowners should also remove hazardous vegetation like juniper and Italian cypress. 

The M.W.P.A. is focused on educating residents about home hardening and defensible space, notifying them of violations but not issuing any citations. The agency hasn’t decided exactly where the line of compliance is, so it is using a conservative definition for now. Even a driveway with a few piles of leaves that haven’t been raked in a few days can result in a violation.

“If you are out of compliance, that means you might have just one dead bush that died in drought,” Ms. Cutter said. “That’s like saying if you took a test, and you got 95 percent, you failed.”

The inspectors don’t issue any citations, but homeowners may have incentive enough to follow their guidance. Many insurance companies require a letter from fire officials confirming compliance before renewing a homeowner’s policy. 

Mark Brown, the executive officer of the M.W.P.A., said the authority considered how to enforce violations, but settled on taking the route of education, leaving the role of enforcement to insurance companies. “We considered, ‘Do we go the carrot route or do we go the stick route?’” Mr. Brown said. “The insurance industry’s a little bit of a stick.”

Many of the fixes recommended by inspectors take time and money from homeowners. The M.W.P.A. has set aside $500,000 from Measure C to give as grants, and it is applying for $2 million more for the same purpose from Cal Fire. 

“We can do all the work in the world, but if they don’t do the work within their own properties, we can’t have a safe community,” Mr. Brown said.

The inspections come at a critical time in the fire season. On Aug. 15, the Marin County Fire Department measured live fuel moisture at 60 percent on Mount Tamalpais. This level of desiccation, which allows fire to quickly rip through vegetation like chaparral, usually doesn’t arrive until October.

“For us that’s a critical threshold number,” Mr. Weber said. “The largest and most devastating fires are in the fall in Marin.”

With fire season getting longer and more severe each year, M.W.P.A. officials believe Marin County homeowners understand the increased risk and are taking their responsibilities seriously. 

“There was a prevalent feeling of ‘It’s not going to happen here.’ That’s what we’re seeing disappearing,” Mr. Brown said. “That idea of ‘It’s not going to happen to me’ is going away.”