Crews work to eradicate invasive, flammable Arundo canes from the Russian River banks in Healdsburg
Healdsburg Fire Marshal Lance Macdonald recalls tending to a fire six years ago that burned so fiercely it melted the soles of his boots.
The blaze started near the Healdsburg Memorial Bridge in a patch of Arundo donax canes aside the Russian River. It was contained without extraordinary effort, with support from Cal Fire — and absent the winds that would rise around the region three weeks later and fan the destructive North Bay firestorm of October 2017.
But the “giant reed,” as it’s also called, threw off so much heat on its own that it wrecked wildland firefighting boots meant to last, Macdonald said.
“When those reeds are on fire, they burn really hot and really fast,” he said.
As fire marshal and division chief for Healdsburg Fire, Macdonald is all too aware of the threat presented by stands of towering Arundo that have spread along the banks of the Russian River, especially near lower elevation Fitch Mountain communities with sizable populations of senior citizens.
Invasive, 30-foot reeds that grow extremely fast in large, dense colonies along waterways, Arundo has become a troubling problem around the nation, outcompeting native flora and sucking up far more water than other plant species would require.
It’s also a major fire hazard.
Posing an alarming risk
After reports that similar, invasive grasses contributed to the deadly Maui wildfires that last week killed at least 111 people, destroyed thousands of structures and scorched large areas of the once lush Hawaiian island, the risk Arundo poses as a ready fuel is all the more alarming.
The plant’s thick, hollow, fibrous canes die and dry out but still stand tall as new shoots rise among them, making for ideal wildfire kindling.
“Ironically, it’s kind of the perfect fuel,” Macdonald said. “It’s dry. It’s upright. It’s hollow. It’s close together.
“It’s all the things you wouldn’t want to have if you’re trying to stop a fire.”
After several decades of steady growth along both sides of the Russian River in Healdsburg, it’s also increased the chance for ignition and wildfire spread in the right conditions.
“The Russian River used to be a defensible space,” Macdonald said. “It used to be a big firebreak, and with the Arundo taking over, it’s kind of lost that ability.”
An Arundo removal campaign along the river in Healdsburg is underway to address some of the problem and is focused on a winding, 5.2 mile stretch up river of Dry Creek to the S curves near Rio Lindo Adventist Academy.
It’s the latest in a series of efforts up and down the Russian River and in nearby watersheds undertaken by the Sonoma Resource Conservation District, the Mendocino Resource Conservation District and several Native tribes in the area, mostly over the past two decades.
Native to Europe’s Iberian Peninsula, south Asia and North Africa, the plant was introduced into North America in the early 1500s and has spread around the southern half of the United States.
Often planted along waterways to prevent erosion, it has become invasive along rivers, creeks and canals, according to the U.S. Department of Agriculture.
A thirsty plant that absorbs far more than other plants from the soil and nearby waterways, it still dries out by virtue of an evapotranspiration rate roughly three times greater than most riparian vegetation.
The Sonoma Resource Conservation District tackled about 1,200 acres in Alexander Valley, beginning around 2013, with the help of state Department of Water Resources funding and the permission of many private property owners.
The more recent Arundo removal work was begun in Healdsburg last year by the nonprofit Russian Riverkeeper, under the umbrella of the city fire department and its fuels management program.
The project got a boost this year with a nearly $1 million grant from the State Coastal Conservancy, awarded in June to cover 70% of the cost. Riverkeeper is raising funds to meet its obligation to finance the remaining 30%.
It is among the community’s key fire prevention priorities, which include forest thinning on Fitch Mountain, in the Healdsburg Ridge Open Space Preserve and around hills to the northeast, Macdonald said.
Those hills are where dry, offshore winds would sweep during high fire conditions like those that threatened the city during the October 2019 Kincade Fire, which forced the city’s evacuation. Those winds are also what makes Arundo extraction along the river so critical, he said.
“The fire that makes me nervous is the fire that’s going to blow into town from that direction,” Macdonald said.