To: Board of Supervisors
From: John Kopchik, Director, Conservation and Development
Report Title: Authorization to construct a retaining wall within a restricted development area on the properties located at 600 and 610 Stanely Lane in the El Sobrante area.
☒Recommendation of the County Administrator ☐ Recommendation of Board Committee
RECOMMENDATIONS:
1. FIND that the project is Categorically Exempt from the California Environmental Quality Act (CEQA), under CEQA Guidelines Section 15303(e);
2. APPROVE and AUTHORIZE, under the terms of the attached grant deed of development rights held by the County, Soil Engineering Construction, Inc. to conduct landslide mitigations, including grading and construction of a retaining wall ranging from 5-11 feet in height and +112 linear feet in length on APN 433-020-056 and 433-020-057 (600 and 610 Stanley Lane) in the El Sobrante area, in accordance with development plan #CDDP23-03014;
3. DIRECT the Director of Conservation and Development to file a Notice of Exemption with the County Clerk.
FISCAL IMPACT:
There is no fiscal impact. The applicant has paid the necessary application deposit and is obligated to pay supplemental fees to cover all additional costs associated with the application process.
BACKGROUND:
The Community Development Division (CDD) previously considered the proposed project under Development Plan CDDP17-03028. A landslide occurred to the rear of two existing single-family residences addressed 600 and 610 Stanley Lane sometime between September 2015, and February 2016. The landslide severely eroded the rear yards and posed a continuing hazard to existing improvements on these parcels. On July 6, 2017, Development Plan #CDDP17-03028 was filed with the CDD for the purpose of constructing a retaining wall to mitigate the landslide area. However, creek bank stability immediately adjacent to the landslide had since worsened and were threatening improvements on two residential lots such that the project proponent considered proceeding with the retaining wall construction to be an emergency and constructed the retaining wall without permits while CDDP17-03028 was still under review by the CDD. The County Zoning Administrator ultimately approved CDDP17-03028 on October 15, 2018. This approval was contingent on the Board of Supervisor’s approval to authorize the retaining wall within areas of the subject property wherein development rights had been dedicated to the County. However, the project was not heard by the Board of Supervisors for approval and unfortunately, the approved development plan expired. As a result, the applicant has submitted the current development plan application (#CDDP23-03014) seeking the same approval for the same project.
On September 4, 2024, the Zoning Administrator conducted a noticed public hearing on the application. No public testimony was received, and the Zoning Administrator approved the application contingent on Board of Supervisor’s authorization to issue building permits legalizing the as-built retaining wall improvements.
CALIFORNIA ENVIRONMENTAL QUALITY ACT (CEQA)
The project is categorically exempt from environmental review pursuant to CEQA guidelines section 15303(e), which exempts, amongst others, projects consisting of the construction of small structures, including accessory structures and retaining walls. The project includes the construction of a retaining wall that has been engineered to mitigate hazardous conditions associated with a landslide which previously occurred on site. There is no substantial evidence that the project involves unusual circumstances, including future activities, resulting in, or which might reasonably result in, significant impacts which threaten the environment. None of the exceptions in CEQA guidelines section 15300.2 apply. The Zoning Administrator’s approval of the Development Plan application on September 4, 2024, included the aforementioned finding that the project was exempt from environmental review under CEQA guidelines section 15303(e).
CONCLUSION AND STAFF RECOMMENDATION
The restricted development area coincides with the creek structure setback area along San Pablo Creek. Considering that the slide plane from the circa 2015 landslide is located within the restricted development area, the ongoing slope stability after the landslide could not be completely addressed absent grading/construction activities within the restricted development area. The as-built retaining wall was designed to minimize construction activity in the creek channel and incorporates recommendations of the consulting geotechnical engineer to address the hazard posed to existing residences by the geologic hazard. Since the restricted area is located immediately adjacent to residences, leaving little to no area outside of the restricted development area where such improvements could feasibly be relocated, staff recommends that the Board of Supervisors authorize the grading and site improvements on portions of APN 433-020-056 and 433-020-057 where the development rights have been granted to the County.
CONSEQUENCE OF NEGATIVE ACTION:
If not approved, development plan County File No. CDDP23-03014 will be denied, existing retaining wall improvements within the restricted development area will need to be removed and relocated outside of the restricted development area.