March-April 2007

A Phoenix From the Ashes

Revegetating after a wildfire

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By Tara Beecham

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“There are many combinations of hydromulch slurries that can be and have been applied,” says Western States Reclamation’s Reid. “For the Cerro Grande [New Mexico] fire, the hydromulch slurry mix included water, hydromulch, fertilizer, seed, poly fibers, and tackifier. In addition to aerial work, a lot of ground work is implemented in these areas: ground mulching with straw and hydromulch, hand seed and rake, wattles, straw bales, silt fence, and contour tree felling.”

Revegetating the area affected by the Coal Seam Fire in Glenwood Springs, CO, which Reid said was caused by an underground coal fire that had been burning for several years, also posed a challenge to pilots.

“Treatment was [applied to] approximately 500 acres of BLM [Bureau of Land Management] land in steep areas above the town,” he explains. “The project used hydromulch slurry, with guar tackifier from Rantec, organic fertilizer, and a native seed mix. The project was completed in eight days. The most challenging aspect was for the pilots, due to the steep terrain.” Overall, says Reid, the treatment applications went smoothly and proved very successful.

Aerial applications for erosion control after a wildfire are a global solution. Aero Tech has worked on fire-damaged landscapes not only in the American southwest, but also in Africa and South America. The company operates two helicopters and 11 airplanes.

Revegetation costs vary depending on the size of project, the company, and the products selected for use, particularly when aerial applications are involved.

“Costs can range anywhere from $5 an acre to $15 an acre, depending on the terrain and distance we have to ferry the [material],” says Stallings. “A light and fluffy seed, compared to heavier seeds … can be put on faster. The bigger project is going to be less per acre than a small project.”

Seeding for Stability
Seeding wildfire-damaged areas can be approached through a variety of methods.

 “We sometimes start immediately, and sometimes it may be four or five months later after the fire, all depending on budget and contracts,” says Stallings. “In 2004, we were seeding the Peppin Fire in Ruidoso, New Mexico, on one side of the mountain while our aircraft and helicopters were still fighting the fire on the other side of the mountain!”

After the Peppin Fire, two seed mixes were used, one on the land outside the wilderness area and another inside the area, according to Bill Agnew, general manager for Granite Seed, based in Lehi, UT. The US Forest Service purchased a combination of mountain brome, slender wheatgrass, and sideoats gramma, all native grasses, as well as orchard grass and mountain mahogany for the outside mix. The seed mix used inside the wilderness area included mountain brome, slender wheatgrass, sideoats gramma, and barley that was used as a cover crop, says Agnew. Barley’s appeal lies in its ability to grow quickly.

Stallings, too, describes the erosion control process following a wildfire as a race against the rain, noting that so much soot is left on top of the soil that if the damaged landscape receives a 2- to 4-inch rain, flooding could wipe out areas such as shopping centers or water treatment plants.

Photo: Revegetation Services
Controlling erosion after a wildfire is a race against the rain.

During a huge wildfire that struck San Diego in 2003, Los Angeles–based Stover Seed Co. was one of the distributors that supplied seed to Northstar Impex Corp. contractors for revegetation. Because of the area’s dense population, there was great concern over protecting the wildfire-ravaged land from damaging property.

“General practice is to get some soil down in critical areas and let the rest come back as is,” says Stephen Knutson of Stover Seed, adding that for the San Diego project, a variety of annual grasses and a few perennials were seeded with the goal of allowing native plants to take hold in the soil once again.

The seed was sold directly to the county. “It’s a trend that counties buy the seed they want and dole it out to different contractors to apply,” explains Knutson.

Seeding to prevent property damage was an issue for Revegetation Services workers involved in repairing an area after the fire that raged between Heber and Show Low in the White Mountain region of Arizona. The wildfire-damaged ground was burned, and water running off the site threatened towns downstream.

“You run into a situation when the ground will not accept any moisture,” says Kurt Anderson, president of Revegetation Services. “It’s an urgent need when you have expected rains.”

The project areas were seeded with native grasses shipped to the site by Granite Seed ahead of Revegetation Services beginning its work in the area.

“We had to attack by both ground and air. We had ground crew putting straw in and air crew dropping straw,” says Anderson. “Access is a big problem with almost every fire we’ve been involved with.

“Within a week after we got onto that watershed, the streams stopped running and the roads were repaired. The straw caused the rain to percolate into the burnt soil and therefore it didn’t sheet off.”

On most of his projects, Anderson says seed that can germinate quickly is used similarly to that of a cover crop. “The native will come in later,” he says. “They want to get the roots into the soil and start holding some of that water.”

When Less Is More
The Croy Fire in Morgan Hill, CA, about 20 miles south of San Jose, charred about 3,000 acres.

“It was very hilly, so the fires went up these canyons very quickly,” says Carol Presley, an environmental engineer and Certified Professional in Erosion and Sediment Control with the Santa Clara Valley Water District based in San Jose.

Photo: Aero Tech
Photo: Aero Tech
Preparing to seed and seeding in Arizona

Before the fire, the plants that had been growing on the chaparral, which has characteristically dry summers, are more flammable than many other species and “very adept at readapting themselves after a fire,” explains Presley. Although it may seem logical to want to revegetate with fast-growing grasses, this is not the course of action she advises for this type of landscape.

“One property owner did apply Italian rye, which was a complete mistake. It suppressed the natives. Don’t be quick to install fast-growing weedy grasses, because you could really damage the existing ecosystem, particularly delicate ecosystems like a chaparral,” says Presley. “The worst thing to do is produce weedy grasses that persist; then they provide a fire hazard in the future.”

After the Croy Fire, workers installed weed-free straw mulch from Pelletized Straw LLC “to provide that first year of erosion protection so that the native [plants] could come back on their own,” she explains, adding that the plants would have included manzanita, ceanothus, and chamise. Mulch was trucked up and down the hilly terrain and most of the mulch was hand-applied by conservation corps workers.

“We did a little bit of hydroseeding on the roads, mostly with plant-based tackifier. There were already roads in place. The idea was to keep our treatments to where the firebreaks were or along the roadsides,” says Presley. “Sometimes the minimalistic approach is the best.”

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A similar plan worked for a revegetation project in 2003. In November of that year, the Dietz Hydroseeding team worked on the Simi Fire revegetation project located along California Route 118 in Simi Valley and Moorpark.

“Because of the imminent threat of rain, there was a three-pronged approach to the methods used. First, a bonded fiber matrix was used because of the ability to cover a large area very quickly to prevent erosion and sediment flow. We were able to protect approximately 150 acres of areas immediately adjacent to roadways and drainage structures in about three weeks’ time,” says Dietz. “Second, in areas that were prone to heavy water flow, straw rolls or wattles and gravel bags were used in conjunction with the application of the bonded fiber matrix. Next Page >

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