Construction is underway to expand the footprint of Cold Springs debris basin.
The project is the first of several upcoming improvement projects for local debris basins within the Thomas Fire burn area.
Santa Barbara County Public Works announced the expansion on Twitter on Sept. 2. Work began in late August and construction on the project is expected to last until the end of September.
According to Public Works deputy director Tom Fayram, the expansion project will increase the basin’s footprint by exporting 12,000 cubic yards of material. He added that when finished, the basin will be able to capture a “widely variable” amount of debris, depending on its content size and type.
Originally built by the United States Army Corps of Engineers to offer Montecito some protection against debris flows during the Coyote Fire of 1964, Cold Springs debris basin has been maintained in the way it was built ever since, until now.
The expansion is particularly meant to increase the basin’s capacity for retaining larger rocks and debris, since the Cold Springs debris basin and other basins in Montecito overflowed during the debris flow on Jan. 9, 2018. According to a board letter from the Feb. 25 Board of Supervisors meeting that approved the expansion project, this will be done by modifying the basin dam and outlet to a design similar to the Gobernator debris basin. This design allows the basin to continue trapping large rocks and debris while finer grain sands and sediment keep flowing downstream.
The Cold Springs debris basin expansion kicks off a series of debris basin projects that includes expansions to the San Ysidro and Romero debris basins. These will happen over the next two years. There are also plans to make a debris basin at Randall Road, officials said.
Because the environmental impacts of the Cold Springs expansion project were minimal and it could be done without seeking grant funds, it moved ahead before the other debris basin projects. Mr. Fayram added that whereas the Randall Road area is land the county must acquire from private homeowners who lost their homes in the Jan. 9 debris flow, Cold Springs debris basin is on county-owned land.
“The reason why this one came in front of the others is that we own the land and there’s no acquisition cost to doing it,” he said.
The Feb. 25 board letter says debris basin projects will be staggered as much as possible to avoid competition for resources. Construction on the project costs around $700,000 and will be carried out by Raminha Construction.
In an interview with the News-Press, Santa Barbara Bucket Brigade co-founder and executive director Abe Powell said expanding the Cold Springs debris basin is an absolute necessity.
“This is going to be needed work,” he said. “Unless they’re going to move all the houses beneath these watersheds, we’re going to need protections.”
He added that the debris basins are due for improvement because of impacts from wildfires and changing climate patterns affecting the watershed above Montecito. The latter includes rain coming to Santa Barbara less frequently but falling more intensely when rainstorms do arrive, Mr. Powell explained.
“The changes in climate have triggered changes in the local environment and ecosystems that force us to look with fresh eyes upon the system,” he said.
Montecito Fire Protection District Chief Kevin Taylor expressed support for the basin expansion and remarked that his department is “excited about any improvement to the flood control system, because those systems make our community safer.”
Montecito Association executive director Sharon Byrne said construction going forward on the Cold Springs debris basin is “a win.”
The basin isn’t expanding as much as she would hope for in a perfect world, as “there’s no debris basin that can catch the mountain,” but Ms. Byrne sees growth of any kind as a boon for Montecito.
“We’re excited because the more we can defend our community from potential geologic hazards, the safer we’re going to be,” she said.
Ms. Byrne added that considering Montecito experienced a debris flow in 1969, five years after the Coyote Fire, such a risk remains just two years after the Thomas Fire.
“We would not be out of the woods if it followed the same schedule until 2023,” she said.