Rocky Fire

The Rocky Fire was a large wildfire in Lake, Colusa, and Yolo counties in Northern California in 2015. The fire burned 69438 acres between its ignition on July 29 and its full containment on August 14. Caused by a malfunctioning water heater being used for illegal cannabis cultivation, the fire destroyed 96 structures and was the fifth largest fire of the 2015 wildfire season in California, during which 8,283 wildfires burned a total of 880899 acres.

Background
The Rocky Fire burn area largely comprised rough terrain of oak woodlands, grasslands, and chaparral, and had no prior wildfire history going back "several decades", according to the California Governor's Office of Emergency Services. This absence is partly attributable to effective fire suppression policies that prevented wildfires from reducing the build-up of vegetation. Dense chaparral had flourished in the meantime, providing plentiful fuel for fire growth. A multiple-year drought then ensued, beginning in 2011. Moisture levels in chamise brush, one of the fuels that characterized the Rocky Fire burn area, had reached near-record lows by the time of the fire, despite September and October typically being the driest months of the year in the state.

Overall, California's 2015 wildfire season was characterized by aggressive fires that, aided by drought conditions, persisted through the night when they were expected to reduce in intensity. By August 8, as the Rocky Fire was underway, the amount of state land burned in wildfires was more than double the five-year average. The Rocky Fire was one of 52 wildfires to exceed 40000 acres in the United States in 2015.

Progression
The Rocky Fire began at a property on Morgan Valley Road, east of Clearlake in Lake County, at about 3:30 p.m. PDT on Wednesday, July 29, when a gas-powered water heater in an outbuilding caught fire and set nearby vegetation alight. Firefighters were initially dispatched to the incident based on a report of a structure fire on Rocky Creek Road; a second fire was later reported on Morgan Valley Road with an unknown cause. The fire was named the Rocky Fire for its proximity to Rocky Creek, which flows north of Morgan Valley Road. Antecedent high temperatures and winds helped the ensuing fire spread rapidly, entering thick brush and woodlands and advancing forward via ember spotting. In several hours, the fire grew from 150 acres to 3000 acres, destroying several outbuildings and necessitating mandatory evacuation orders for about 500 residents. A total of 350 firefighting personnel were engaged on the fire in the first day, joined by eight air tankers and eight helicopters.

By the following afternoon, the fire had burned 8300 acres and forced residents of Lower Lake and nearby roads to evacuate while pushing into the Cache Creek Wilderness and the Berryessa Snow Mountain National Monument. By that night, the Rocky Fire spanned 13500 acres in area and was the largest active wildfire in Northern California. After originally confining itself to a rugged area bounded by California State Route 29 to the west and 16 to the east, the fire became much more active on Saturday, August 1, as temperatures reached more than 100 degrees °F and relative humidity levels approached zero percent. Using bulldozers, firefighters built containment lines ahead of the Rocky Fire's northern and eastern flanks. Toward the end of the day, the fire's rate of spread vastly exceeded what had been predicted by computer modeling, consuming 20000–22000 acres in a five-hour period. A public information officer with Cal Fire described the growth as "really unprecedented in recent times, or in even veterans of our department’s recollection" for a wildfire not influenced by strong winds. The fire routinely produced large pyrocumulus clouds up to 35000 ft in altitude, which had a tendency to collapse and spread the fire erratically when the downdrafts reached the surface. The Rocky Fire continued to burn actively that night and through the following day. Fire personnel abandoned the containment lines they had built on the northern/eastern flanks, retreating several miles further north to California State Route 20 (CA 20) and further east to California State Route 16 (CA 16). There, they conducted firing operations, burning off fuel between the highways and the fire itself so as to halt its growth in those directions. The Rocky Fire reached approximately 54000 acres in burned area with five percent containment by the end of Sunday, August 2.

By Monday, August 3, fire activity was expected to calm as an incoming weather system brought temperatures down and relative humidity up. In the afternoon, the Rocky Fire crossed CA 20 to the north, despite the firing operations and other preparations the previous day. The fire burned up-slope in a drainage near Cache Creek, creating a large plume that—in combination with a sudden wind shift—caused ember spotting up across the highway up to 1 mi away in Long Valley. The fire then proceeded to burn through a subdivision, destroying multiple structures, as it moved north towards Indian Valley Reservoir.

On Tuesday, August 4, White House Press Secretary Josh Earnest said that President Barack Obama had been briefed on the fire by Lisa Monaco, one of his national security advisors, and that the White House would continue to monitor the situation. That same day, the National Interagency Fire Center ranked the Rocky Fire as the highest-priority wildfire in the country for additional equipment and personnel. By August 5, at roughly 69600 acre, the Rocky Fire's burned area was more than four times as large as that of any other active wildfire in California, though only the portion of the fire perimeter that had burned across CA 20 remained un-contained.

Despite the setback, by later in the week improved weather conditions had allowed firefighters to double the percentage of the perimeter listed as contained in two days. The number of personnel assigned to the Rocky Fire peaked at more than 3,500 people on August 6. This included hundreds of inmates in the California Department of Corrections and Rehabilitation system worked as firefighters on the Rocky Fire, earning between $1.45– $3.90 per hour, plus a bonus $1.00 per hour for working on a fire.

The fire was declared 100 percent contained on Friday, August 14. The total area burned in the fire was calculated at 69438 acres, adjusted down from 69636 acres by more accurate mapping. According to the National Interagency Fire Center, the cost of fighting the fire came to $46.1 million at the time, or roughly equivalent to $million in, adjusted for inflation.

Cause
On August 17, 2016, California Department of Forestry and Fire Protection (Cal Fire) officials announced that the Rocky Fire had been ignited by a malfunctioning gas-powered water heater strapped to a tree and housed in an outbuilding filled with flammable liquids, associated with an illegal cannabis growing operation. A spokesperson called the arrangement "inventive" but "not very safe". Two suspects in the fire—not named by Cal Fire—fled the country before investigators could question them. The Rocky Fire was one of five wildfires related to cannabis cultivation in Northern California in 2015.

Effects
No injuries or deaths resulted from the Rocky Fire. The 96 structures destroyed in the Rocky Fire comprised 43 homes and 53 outbuildings, and a further eight structures were damaged. Most of the burned buildings were in the Morgan Valley area, near the fire's origin. The fire was the third most destructive of the year in California, its toll exceeded only by the Valley Fire in Lake County and the Butte Fire in Amador County.

Closures and evacuations
The number of people affected by mandatory evacuation orders issued because of the Rocky Fire reached 1,480; when including voluntary evacuation warnings the approximately 13,000 people were affected. Some residents were forced to stay in hotels, some in one of the two Red Cross shelters established nearby, others in tents in parking lots. After fire growth and suppression operations had forced their closure on August 1, California State Routes 20 and 16 re-opened on Friday, August 7. Evacuations were lifted and all road closures but one were lifted in the morning on Saturday, August 8.

Political response
On July 31, 2015, California governor Jerry Brown declared a state of emergency in response to the Rocky Fire and the multiple other wildfires burning in Northern California. On August 6, Brown visited the Rocky Fire area, meeting with impacted residents and firefighting personnel as well as using the opportunity to speak about the impacts of climate change in California.

Environmental impacts
Smoke from the fire was carried southeast towards Sacramento, where authorities issued air quality advisories for those with pre-existing respiratory issues. Lake County wineries fretted about possible smoke impacts to grape flavor, but as favorable prevailing winds pushed smoke east instead of west towards the bulk of the county's vineyards, impacts were "minimal to none".