New Debris Basin Coming to Montecito Area Flooded During 1/9 Debris Flow

Santa Barbara County Supervisors Also Approve $3.4 Million in Improvements to Cold Spring and Santa Monica Debris Basins

This culvert under Park Lane in Montecito clogged during 2018’s 1/9 Debris Flow, with the overflowing water, rocks, and trees affecting about 40 homes downstream. | Credit: Paul Wellman File Photo

Work will begin in summer 2025 on a new debris basin for Montecito, a community that lost 23 souls along its creeks in the tragic debris flows of January 9, 2018. In addition to the new Buena Vista Creek debris basin, the Santa Barbara County Board of Supervisors approved funding to improve Cold Spring and Santa Monica debris basins on Tuesday.

The Buena Vista debris basin will be relatively small — 0.65 acres compared to Cold Spring’s 2.4 — but will be about twice as deep, said Matt Griffin with County Public Works. The culvert under Park Lane clogged during the 2018 debris flow, with the overflowing water, rocks, and trees affecting about 40 homes downstream. In the work to come, a debris rack will be positioned in front of the culvert, while the floor of the creek will be widened to catch more debris, Griffin said. The rock and soil from the widening is to be “windrowed” up-channel to help contain the flows.

The newly approved Buena Vista Creek debris basin will add a debris rack in front of the culvert and widen the floor of the creek to catch more debris. | Credit: Santa Barbara County Public Works

The vertical walls to either side of the basin will be sandstone-colored, he noted. The Buena Vista Trail crosses above the debris basin location, and Griffin said they would try to keep it open, but it was inevitable that it would close at times. The work may take about a half-year to complete, at a ballpark cost of $2.5 million. Easements for two Park Lane parcels were purchased for $1.462 million to hold the basin, with about $240,000 coming from the Federal Emergency Management Agency (FEMA). The ring nets upstream were removed last year.

Another $3.4 million was approved by the supervisors on Tuesday to improve Cold Spring debris basin, which has an old-fashioned concrete and rock wall to hold back storm waters. To improve fish and sediment passage and the basin’s ability to capture debris, the old wall will come out this summer and be replaced with constrictor walls, as were installed at the Romero Creek debris basin, Griffin explained. About half the Cold Springs funds are a grant from FEMA. San Ysidro debris basin will be similarly improved, but the costs have yet to be worked out.

The Santa Monica debris basin above Carpinteria was instrumental in saving lives and property during the atmospheric-river-fed January 2023 storm, Griffin said. The inlet towers — which allow water to flow out as the basin fills with solids — had not been completed when the storms hit, and changes to the basin have been ongoing for two years to get it to full capacity. The improvements are about to be finished, Griffin said, and the approval on Tuesday of another $223,000 for the contractor overseeing construction and inspection will get the work to the final stretch. The funds for Santa Monica debris basin have come from the Natural Resources Conservation Service.