After 13 days and approximately $4.8 million spent, the U.S. Forest Service has completed its hydromulching treatment on the land burned in this summer’s Gap Fire.

The Forest Service announced the completion of the project on Monday, nearly two weeks ahead of schedule. Six small airplanes and one large helicopter, based out of the Santa Barbara Airport, delivered 3.5 million gallons of the hydromulch in a series of 3,238 flights over the course of the project.

According to the Forest Service, the hydromulch — an organic mix of recycled paper, water, a temporary green dye and a binding substance — will harden and bind to the soil on the hillside, preventing erosion and creating an environment for native vegetation to grow.

Kathy Good, public affairs officer for the Los Padres National Forest, said that the mulch does not contain seed or fertilizer, but serves as a protective cover to prevent the soil from erosion until native vegetation can grow.

“The mulch will be most effective during the first winter, the first rainy season,” Good said. “Its purpose is to provide protective cover for the soil so that when impacted by rainfall it will help hold soil in place. Without it the soil would be washed downslope and downstream.”

Good said that vegetative cover has already begun to regrow on the burned land, although the area will take several years to fully recover from the fire.

“We have already seen regrowth in some areas — it started as early as August, as is typical in a chaparral environment — and we expect to see regrowth in some areas through the winter and next spring,” Good said. “It takes about three to five years for the vegetative cover to become established to the point where it can function the way it did prior to the fire.”

The treated land will remain closed to the public for approximately a year, although Good said that some areas, including Lizard’s Mouth, will be reopened by the end of this week. However, Good said the effectiveness of the hydromulch treatment depends largely on the cooperation of the public.

“I can’t emphasize enough how important it is for people to stay off of mulch,” Good said. “I know people will be tempted to violate the closure and cross through the mulch land, but we really, really want them to cooperate. If the mulch is compromised it won’t function.”

With the treatment of the national forest land complete, the county has started a second hydromulching project to treat the remaining private and non-federal public lands affected by the fire.

According to Santa Barbara County Communications Director William Boyer, the county project closely resembles the Forest Service’s, but targets the burned area that extends beyond the national forest land.

“What we’re focused on are non-Forest Service lands, the private ranches and basically those areas that served as key buffer zone and fire break area for the Goleta community after the fire came down from the national forest land and burned in the foothills,” Boyer said.

Boyer said the county is picking up where the Forest Service left off, using the same method of treatment for the burned areas as well as the same contractor for the hydromulch. The project is expected to take a week to 10 days to be completed, depending on weather conditions, and will cost the county approximately $3.2 million.