Lafayette commission approves retaining wall and variances for slope failure at 337–339 Carlisle Terrace

The Lafayette Design Review Commission on Sept. 22 approved hillside development permits and variances allowing construction of a retaining wall to stabilize a slope failure behind 337 and 339 Carlisle Terrace.

Monica, the city planner for the item, told commissioners the project would install a soldier‑pile retaining wall spanning both parcels to stop ongoing instability and would be exempt from CEQA under the section cited in the staff report. Staff recommended adoption of Resolution 2025‑16, contingent on added conditions addressing remediation and drainage.

The project responds to a slope failure that occurred along the shared rear property line of two single‑family lots. Monica said the proposed work area is about 400 square feet and the wall would range from 4 to 9 feet in height, be founded on 18‑inch‑diameter piers, include tiebacks and an integrated subdrain system, and be topped with a 42‑inch epoxy‑painted metal guardrail for safety. She said equipment access would be through the front and right side yards of 337 Carlisle Terrace and that no tree removals were proposed. The staff presentation noted an existing 3‑foot wood wall and a 4.5‑foot concrete block wall had failed during the landslide.

City engineering review prompted three additional conditions of approval beyond the standard list. Those conditions require (1) a supplemental slope remediation plan evaluating the lower portion of the slide, (2) clear identification of drainage responsibility and a maintenance mechanism or easement, and (3) a revised site drainage plan showing how runoff from the homes will be diverted away from the slope. The staff report also states that public notices were mailed to property owners within 300 feet and posted on site at least 10 days before the hearing; no written or verbal comments had been received by staff before the meeting.

At the hearing the applicant said the slope failure dated to about 40 years ago and that the timeline to complete the work was tight. "We're gonna spend a lot of money to make sure this time there," the applicant said, and added, "It's gonna be tight. We're eager to get this." Commissioner Armand Heidelick said, "I'm happy to support this engineering as proposed tonight," and Commissioner Richard Stanton added, "I have no issues. I support. It's doable." Commissioners voted 3‑0 to adopt Resolution 2025‑16, with Heidelick moving the resolution and Stanton seconding.

A nearby resident, Aaron Patel of Oak Harbor, spoke during public comment saying he had recently moved into the neighborhood and that observing the slope failure had concerned him about his own property's stability. Staff and the applicant noted that the supplemental slope remediation plan and revised drainage plan are intended to address remaining erosion and runoff concerns raised by the city engineer.

The commission approved the permits and variances subject to the conditions in the staff report and the three additional engineering conditions. The applicant said the engineering firm would be contacted the following day to begin work toward meeting those conditions.