Six years after deadly debris flows devastated Montecito, the Federal Emergency Management Agency is nearly done with updated flood zone maps for the region.  

The topography had changed, and LIDAR scanning was used to create a more accurate picture of flooding risk to local properties, according to Santa Barbara County Flood Control.

Preliminary versions of the new special hazard flood area maps will become public in late March, according to Matt Griffin, Flood Control’s engineering manager.

The maps cover the South Coast region between Sycamore Creek in Santa Barbara and Rincon Creek at the Ventura County boundary. There will also be updates for three creeks in the Santa Ynez Valley, from Buellton to Solvang.

FEMA flood risk maps affect development decisions and insurance for individual properties. Griffin updated the Montecito Planning Commission on the process at last week’s meeting.

About 1,400 parcels in Montecito will be affected by the new maps, including properties being added to, removed from or staying within the flood zone.

Griffin, who has seen the draft maps, said they are “very generally, very roughly more in line with the current effective mapping and not the recovery mapping.”

After the Jan. 9, 2018, debris flows killed 23 people and damaged hundreds of homes in Montecito, the county worked with FEMA to develop “recovery maps” identifying hazards in the new landscape.

“The recovery mapping was unique,” Griffin said. The update is “essentially reverting to conventional mapping standards,” he added.

The FEMA flood risk maps do not consider clogged culverts or bridges as the recovery maps did. They also do not consider a burned watershed, which would create higher peak flows, Griffin said. The new maps do take debris into account, “because all flows in Montecito contain large amounts of debris,” he said.

“With that said, all the four major creeks that discharge to the ocean do have breakouts upstream of Highway 101” in Montecito, meaning they leave their channels in flooding events, Griffin said.

Oak Creek, San Ysidro Creek and Romero Creek create a “comingled, joined flood plain” between them, he added.

The flood zone maps will have a public review period and appeal process before they’re finalized.

That could take awhile; maps may not become final and effective until 2026, Griffin said. The county could choose to adopt the preliminary maps before then, to be used for development decisions, he added.

Looking at the current effective map, the recovery map and the preliminary map drafts, Griffin said, “rarely does new mapping show to be more conservative than the recovery mapping.”

FEMA expects to release the new maps to the public in late March, he said. The agency started the process in 2019.

View the recovery map and the current FEMA flood zone map on readysbc.org.

Montecito Highway Project Sound Walls Decision Based on Recovery Maps

Planning commissioners were frustrated that they haven’t seen the maps yet, and that the decision to replace Highway 101 sound walls with chain-link fences was made before the new maps were released.

“We made decisions a year ago about how to proceed with Caltrans based on this information eventually being available to us,” Commissioner Bob Kupiec said. If there are any substantial changes to the conditions, “we want to know about it,” he said.

The recovery map was used to evaluate hazards for the sound wall part of the project, while the current FEMA map was used for other elements of the project, according to Flood Control.

“Sound walls probably wouldn’t be feasible without channel capacity improvements,” Griffin said.

In 2022, project agencies announced that the Montecito segment of the highway project would have chain-link fences with vegetation, not sound walls, because of flooding risks.

The highway in that area acts “like a bathtub” for all the water that comes down from the foothills, project consultant Kirsten Ayars said at the time.

Residents appealed the chain-link fence decision to the county Board of Supervisors, which sided with the project agencies.

In Montecito, all lanes of Highway 101 flooded with water and debris and became impassable for almost two weeks after the 2018 debris flows.