By Tara Beecham
Erosion Control magazine, the official journal of the
International Erosion Control Association
Hydroseeding, hydromulching, and ther techniques on
Red and orange filled the sky last autumn in southern
California, but it was the unrelenting flames of extensive
wildfires, not leaves changing their seasonal colors. When all that
is left in wildfire-damaged areas is ash and charred soil, is it
better to seed or just help nature take its course by providing a
stable environment for the seed left in the soil to thrive? This is
one of many questions posed in the state as workers mobilize their
erosion control efforts.
Many areas are still coping with fire damage. For example, the
Ammo Fire in San Diego County burned more than 21,000 acres, the
Santiago Fire in Orange County blazed across 28,400 acres, and the
Poomacha Fire in San Diego damaged more than 49,000 acres,
according to statistics released by the California Department of
Forestry and Fire Protection. In October, CNN reported that as a
result of the wildfires, more than 500,000 people were forced to
evacuate their homes in the hardest-hit area of the state, San
Diego County. The bill for such destruction is steep: The October
2007 wildfires caused more than $1 billion in damage, according to
the Arlington, VA-based conservation organization, The Nature
Erosion has already occurred in some areas of southern
California that at press time had experienced a large rain event,
explains John Munn, a Sacramento-based soil scientist with the
California Department of Forestry and Fire Protection. Munn served
as an advisor to the Burned Area Emergency Response (BAER) team
that was involved with the Canyon Fire in Malibu, CA.
"It's worse than average," he says of the 2007 wildfires. "I
don't know that you could say it was worse than 2003. It's a bad
year for anybody whose house burns down."
Following the October 2007 California wildfires, California
Governor Arnold Schwarzenegger called upon the state's Blue Ribbon
Fire Commission to assess the next steps that will be taken at all
governmental levels to prevent and battle future fires. In
November, the House-Senate Conference Committee approved $500
million for risk recovery, emergency fire suppression, and recovery
needs related directly to these southern California wildfires.
Several conditions in fall 2007 created the ideal setting for
the spread of these blazes.
"Southern California is a fire chaparrals area," says Ron Dietz,
president of Dietz Hydroseeding of Sylmar, CA, explaining that
there were extreme Santa Ana wind conditions blowing 70 miles per
hour, making the spreading fires virtually unstoppable. These are
usually dry winds in very low humidity. "They increase the
temperature. We've had a drought situation. Even some of the areas
that burned in 2003 reburned. The issue is that they are building
homes more into these areas that are native wildfire areas. It's
like building in tornado alley. Where you decide to build your
structure is impacted by the natural conditions."
When wildfire does produce extensive damage, as is the case from
the October blazes, temporary measures may be used to protect areas
vulnerable to mudslides or ash washed down a hillside by heavy
Straw wattles or silt fencing may be needed for erosion
protection, depending on the situation's severity, according to
Gary Weems, president of Hydro-Plant. Sand bags, too, may be used
when there is a risk of heavy rain. In high-flow water areas,
erosion control blankets would be a consideration, says Dietz,
whose company is also working with residents of Orange County
affected by the Santiago Fire.
"Sand bags or gravel bags can be used at the bottom of slopes in
place of straw bales," he says. "When you get into straw bales,
they really should be maintained. That's another consideration. If
any material gets behind that, it fills it up. Then a big rain
comes, and it breaks loose and goes all at once. That's why they
really don't like to use it until they really have to."
For post-fire recovery sites where hydroseeding is an option,
seed choice is very important to the well-being of the area.
Workers at S&S Seeds, a wholesale native seed and erosion
control supplier based in Carpinteria, CA, provide guidance for
companies working to hydroseed post-fire recovery sites. "We are
filling various seed mix prescriptions, ranging from true
California native species like Cucamonga brome and small fescue to
non-native sterile cover crops like QuickGuard," says Bruce Berlin
of S&S Seeds, referring to recovery efforts from the 2007
fires. "Each different agency or region is developing its own
particular seed mix components based on the site criteria and plant
"Our company has the ability to help them with the seed counts,
seeding rates, and supplying the mix components. We are the largest
supplier/producer of native seeds with origins in southern
California. Timelines and product availability do enter into the
criteria for both product and seed selection. You have to be able
to supply the materials immediately so the slopes can get protected
and covered prior to the onset of fall rains."
Berlin notes that seeds grown commercially in other regions are
not, in many cases, acceptable for use in sensitive California
Dietz Hydroseeding is helping private landowners in Malibu
recover from the October fires, using a bonded fiber matrix and, in
some instances, a seed mix.
"If you've got a homeowner who has a half-acre site and they
want to protect a quarter acre, it's viable for them to use the
more expensive product to get better protection," says Dietz,
referring to the hydromulch mixtures added to the affected areas
and noting that the company is using some native grass seeds,
includingVulpiaand some nassellas, in that area as part of the mix.
"In the Malibu area, there are a few areas that are using native
seeds. Grasses tend to germinate and grow quicker. You get a lot
more plants per square yard than shrub seeding. Some of the
homeowners want to put wildflowers in [such as] California
Most people today not only seek a quick ground cover but also a
suitable native occurring naturally in the burn zone, says Berlin,
unless it is "a non-interfering-with-native annual such as the
QuickGuard." Berlin also stresses that, in some instances, seeding
is not an agency's first choice.
"Contrary to what many people believe, the Forest Service does
not automatically reseed burn areas," he says. "The BAER teams
evaluate the seed bank and erosion control concerns and then
develop a plan to address potential erosion and sediment control
click here for full article.