Look down from a hill over Cameron Park, and you mostly see a lush canopy of trees. The trees conceal the 7,600 homes there, homes they shade, cool and threaten.
"It just looks like a carpet," said Cal Fire Battalion Chief Mike Webb. "When you add up all the conditions and lots, we certainly have a recipe for a bad day."
Cameron Park sits on land that Cal Fire the state Department of Forestry and Fire Protection deems highly hazardous for wildfire, and it is a focal point as officials prepare for the imminent fire season. A plant preserve full of wildfire fuel overlooks the town 35 miles east of Sacramento.
Despite those risks, the number of homes in Cameron Park grew 30 percent during the last decade, largely during the construction boom.
The rest of the region also built heavily in wildfire hazard zones, adding about 17,000 homes to risky areas from 2000 to 2010, according to a Bee analysis of new census figures, housing permits and fire hazard maps.
While much of the growth occurred in suburbs like Cameron Park, homes also went up in the hinterlands. Builders in Grizzly Flats and Happy Valley, two El Dorado County communities far from population areas but close to thick national forest, erected 140 houses during the past decade.
In the North Upper Truckee area near Lake Tahoe, developers added 60 homes just before the Angora fire ripped through in 2007, causing massive damage.
Local leaders approved this construction in principle decades ago through general development plans that created parcels in forest and scrubland. Thousands of parcels subject to those plans still sit fallow, waiting for the housing market to rebound.
This type of hazardous construction is not unusual in California. With natural disasters prevalent, risk is inherent when building: The ground either shakes, floods or burns. But wildfire destruction and costs rose dramatically during the last decade as more homes stood in the path of fire and more fuel blossomed.
"The landscape is gorged with brush, trees and other fuel," said El Dorado County Supervisor Ray Nutting, a longtime Happy Valley resident. "We're going to continue to have people move into these areas because we are only about 60 percent built out."
The state spent $2.4 billion on emergency wildfire suppression in the last 10 years, up 130 percent from the previous decade, after adjusting for inflation. Wildfires leveled 12,000 structures in Cal Fire areas over the decade nearly quadruple the number from the 1990s and killed almost 40 people.
Several communities, including Cameron Park, Happy Valley and Grizzly Flats, have tried to avoid similar disasters by building defensible space around their homes. Properties in these communities were cleared of brush and thick canopy, greatly minimizing the threat posed by wildfire.
But, like other mountain developments, these communities also hope to get lucky.
"For every summer we make it through, we think, 'Are we going to make it through the next one?' " said Cameron Park resident Barbara Rogers. "This area, along with many others, could be the next Oakland Hills."
The threat grows
The Oakland Hills firestorm destroyed almost 4,000 housing units and killed 25 people during the 1991 fire season. It began as a grass fire, spread out of control, generated its own wind and sent embers from home to home.
Rogers isn't making a trite analogy alluding to an Oakland Hills-like fire in Cameron Park. The community's fire protection plan makes the same comparison. Often during the fall, wind flows from the east and swirls over the dry shrubs and trees, much as it courses over the Bay Area.
Matt Silva, who served as the town's fire chief for more than a decade and retired about five years ago, said: "There are areas in Cameron Park where you could have whole neighborhoods go up with the wind. When winds go to 30 or 40 miles per hour, I've seen embers jump a quarter of a mile."
Fire dangers are prevalent in the community. Brush and trees crowd homes with wood siding, decks and shake roofs. Newer homes built with hardier materials are interspersed with older dwellings.
Surrounding all these homes is a mixture of grass savanna, oak trees and chaparral brush.
The chaparral is most common on the hill overlooking the town's east side. This is home to 455 acres of the Pine Hill Preserve and a big cause of worry for Cal Fire, which considers all the area around the preserve as very high risk.
The preserve was set up a decade ago to protect eight types of rare native plants, including three found only in this area.
Development plans, now largely set in stone, were approved decades before the preserve even existed.
"We can't harm the plants, so there is limited abatement we can do," said Ron Briggs, the El Dorado County supervisor whose district includes much of Cameron Park.
The federal Bureau of Land Management recently built a 100-foot firebreak between Cameron Park and the preserve. The break "will slow fire down," said Brian Mulhollen, a bureau fuels management specialist. "It will not stop it. It buys time."
To mitigate the risks posed by the preserve and other fuel, Cameron Park implemented strict clearance and weed abatement rules with potential penalties. Most residents comply. But some don't, particularly out-of-town developers and banks that own empty lots, said Webb, the town's fire marshal.
On the southern end of the plant preserve, for instance, the 100-foot buffer stops dead as it hits a private, vacant lot full of neck-high shrub. The shrub creeps against a private yard and large house. Nearby, another empty lot next to a retirement community is overrun with chaparral.
Thy neighbor's space
The dichotomy of defensible space next to unkempt land also plays out in Happy Valley, about 20 miles southeast of Placerville.
Most developed lots in Happy Valley are like those owned by Charley Ramirez, a former San Francisco transportation worker, and Jill and Bruce Kunder, former Silicon Valley residents.
Ramirez built his home about seven years ago and has meticulously cleared the property of brush and scrub, installing tanks holding more than 10,000 gallons of water. The Kunders' property looks like a park, free of brush and dotted with well-spaced trees.
"We do the best we can to prevent a fire up here," Bruce Kunder said.
If a fire did sweep the properties maintained by Ramirez and the Kunders, it would likely stay on the ground instead of rising through trees making it easier to extinguish, said Nutting, the county supervisor, who co-owns a Happy Valley logging ranch. He helped many neighbors build defensible space, and praises similar efforts in nearby Grizzly Flats.
But a few of Nutting's neighbors have not been cautious, telling him and others that they prefer to keep brush on their property for aesthetics or privacy.
Near Ramirez's home, for instance, a property conforms to minimum requirements. Lining its periphery is underbrush leading to 10-foot-tall manzanita scrubs, leading to 150-foot-tall pines. It's a recipe for a "ladder" fire that starts on the ground before moving up the trees and quickly spreading through the canopy.
Were it not for homes in areas like Happy Valley, U.S. Forest Service firefighters would likely let more wildfires burn themselves out.
Federal officials spend $82,000 more a day on a wildfire within six miles of a single home than on wildfires near undeveloped land, according to Patty Gude of Headwaters Economics, which studies Sierra Nevada wildfire costs. The bill rises incrementally with each additional home.
Upfront costs also occur. Fire Safe councils across the region have taken millions in grants to protect their communities. The grants may eventually save dollars by reducing fuel near homes; however, they also effectively subsidize development.
State firefighting costs have risen too, but Cal Fire spokesman Daniel Berlant said that is largely due to recent, bad wildfire seasons. Cal Fire immediately attacks nearly all wildfires in its jurisdiction.
The nonpartisan Legislative Analyst's Office disagrees, saying construction increases spending. State costs per acre burned a figure that partially controls for bad fire seasons have skyrocketed, state data show.
A paradox swirls around all this: The better that firefighters do their jobs, the more fuel they leave for the next fire.
Nutting and others hope the government will do more to reduce fuel, which happens naturally when officials let fires burn.
"We are not just sitting around waiting for fire we are reducing the fuels," Nutting said of landowners. But on public land, "the problem is when you put out the fire, the fuel source gets worse."