Station fire–impacts and recovery

…The chief concern is the impact the 246-square-mile Station Fire is having on the watershed. Countless canyons, ravines and gullies funnel watercourses toward communities at the forest’s edge.

The Los Angeles County Department of Public Works maintains a legendary flood-control system including 14 major dams, 500 miles of open storm channel and a nearly 3,000-mile network of underground storm drains capable of carrying storm water and debris through the metropolitan region to the ocean.Photo: Esther

The system also includes basins — 30 to 40 in the area impacted by the fire — that intercept debris-laden flows from the canyons and trap mud and vegetation before the water continues on.

“Our concerns are that we will have a larger quantity of debris than normal being captured by our flood control system and, primarily, that individual property owners may be impacted by mudslides or mudflows to their properties,” said Mark Pestrella, public works deputy director.

An overall assessment to predict the water flow has already begun. The basins are being examined to determine how much they may need to be cleaned out to create capacity, and channels are being examined to make sure they are free of obstruction such as overgrowth, Pestrella said.

That work will be done by Oct. 15, which the department marks as the start of the storm season, he said.

Teams will also fan out to assess burned slopes to warn homeowners and determine if temporary structures need to be built.

In Big Tujunga Canyon, Joseph Stachura can already see the danger: The fire left boulders unsupported on a barren slope above his home.

“That’s pretty scary,” he said. “I’m going to have to send the wife and kids out again when it rains because there’s a good chance this hillside is going to move.”

Rocks have already fallen on forest roads.

[…]

Scientists say it is too early to know what kind of long-term damage the Station Fire wrought on the forest ecosystem. Chaparral generally is highly adapted to a fire-prone environment.

But researchers are concerned that if chaparral burns too often, invasive weeds and flammable grasses could crowd out native shrubs, transforming the landscape.

“If we end up with these areas burning again in a couple of years for whatever reason, then you can end up actually changing native vegetation to exotic vegetation,” said Travis Longcore, research associate professor of geography at the University of Southern California.

Many ecosystems can bounce back from devastating fires as long as the blazes are not frequent.

“The reality is there have been fires in the past and there will be fires in the future. Unless you want to pave the mountain, we have to accept that fact,” said Longcore, who is also the science director of the nonprofit Urban Wildlands Group.

Jon Keeley, a research ecologist with the U.S. Geological Survey’s Western Ecological Research Center, said burned areas should sprout without trouble since they haven’t faced repeated fires, and recovery is likely to be very quick.

“Next spring, assuming we get reasonable rain, most of those hills should be green with regrowth,” Keeley said.

He said the forest will also see an increased diversity of native plants since many seeds lie dormant in the soil waiting for a fire to pass through in order to grow.

Thanks Dick