RSF Association working to battle 2019 fire season

Defoliated, non-native eucalyptus trees in Rancho Santa Fe pose a fire risk.
(Caitlin Kreutz)

Last week Rancho Santa Fe Association Parks and Recreation Assistant Manager Caitlin Kreutz listened in to the bi-annual meeting between NASA and the US Forest Service as they talked about the evolving technologies for increasing information and timeliness of data collected for wildfire prevention.

One of the major takeaways from the meeting was a bit sobering: 2018 was the high watermark for California wildfire destruction to life and property and 2019 is expected to be comparable or even worse due to excessive fuel buildup from winter rains.

At the Rancho Santa Fe Association’s board meeting on July 2, Kreutz shared the ongoing work the Association is doing to keep the community fire safe.

In her three years at the Association, Kreutz has made it a focus to get grant money to clear out some of the highly flammable invasive species in the Covenant. To date, she has raised $436,000 for the Association to take out dead and dying eucalyptus and other at-risk invasives. With help from grant funding, this year the Association also plans to plant 450 new trees in the Covenant.

The Association is on year four of a collaborative project with the California Native Plant Society, the US Fish and Wildlife, the San Dieguito River Valley Conservancy, Fairbanks Ranch, the RSF Fire Protection District and a lot of private homeowners to remove hazardous wildfire fuels.

“This is a huge group effort,” Kreutz said of the project that began with 10 acres in the San Dieguito River Valley in 2015 and has grown to 105 acres, 95 acres of which have been treated.

In addition to fuels removal, the project includes native plant restoration and providing information to homeowners to protect their properties and families.

The project is focused on the two main fire corridors that go directly into the Ranch, “funneling flames stoked by invasive species.” The Arroyo Preserve is part of the lower San Dieguito River Valley which acted as a key fire corridor in the 2007 Witch Creek fire and the Lusardi Creek corridor is where the 2014 Bernardo Fire blazed through.

All of the trails within the corridors act as capillaries for wildfire, Kreutz said, and the goal is to cut it off and attack those two high-risk areas.

“A systematic and comprehensive invasive plant control program will provide a substantial fire protection benefit to the residents of Rancho Santa Fe and to the native fauna and flora that live right there in the Arroyo Preserve,” Kreutz said.

Kreutz made note of the three-acre brush fire that happened just outside of Fairbanks Ranch in June in the Lusardi Creek corridor—she said luckily crews had done some work in that area and it is the first project of fall 2019 in tandem with more work in the Arroyo Preserve.

The main invasive species the river valley is up against are the dead and dying eucalyptus and the arundo donax, both of which create extreme fire prone conditions within the riparian habitat.

Over the last few months, the eucalyptus have been defoliated by the infestation of lerp psyllid insects. “The lerp sucks all of the juices out of the leaves and they just fall and that is an incredible fire risk,” Kreutz said.

The arundo, which has stands that have grown very tall in the river valley, burns very hot and just like the eucalyptus, throws embers everywhere in a fire event.

Kreutz said she gets a lot of questions about the removal treatment methods that are being used.

Down in the river valley, crews cut down the stump of eucalyptus and where machinery can’t get to, they drill holes and apply herbicide with what is essentially an eye dropper.

After the arundo is chopped, herbicide is painted on the remaining “stubble” so it doesn’t re-sprout. They have to apply the treatment many times, then mulch it over so it doesn’t come back.

“We are not spraying,” Kreutz said of the herbicide that is applied by state licensed applicators with the California Native Plant Society.

The work does not take place close to any trails and the herbicide dries and is completely inert 30 minutes to an hour after application. The herbicide is non-mobile and will not harm the surrounding habitat.

The RSF Fire Protection District has stated that the negligible risk of herbicide use pales in comparison to the risk of life, limb and property due to wildfire, according to Kreutz.

“Of course the Rancho Santa Fe Association shares residents’ concerns about using any chemicals, especially herbicide,” Kreutz said. “But the goal of this project is ultimately to reduce fire risk by restoring natural areas. While all chemicals pose risks, substantial research shows that this restoration practice is one of the most benign approaches that we have.”

RSF Association Director Steve Dunn questioned why they would be planting 450 new trees, particularly down in the river bed, when perhaps lower lying native shrubs would create less fire risk.

Kreutz said most of what they are planting is low growing—the tallest tree that they plant is the sycamore, which has a very spongy bark that is fire retardant.

“Native species don’t burn as hot. They don’t have those combustible oils and they aren’t as tall so they’re not throwing embers,” Kreutz said.

By removing the water-guzzling invasives, there is more water for the native flora and fauna to flourish.

“A riparian area should be where a fire stops,” Kreutz said. “And naturally, when it gets to be a healthy riparian area, it will.”