35.35.130 Regulations – Geologically hazardous area buffers.
(1) Landslide Hazard Areas (Nonchannel Migration Zone). New uses and developments shall maintain minimum buffers from the top, toe and all edges of landslide hazard areas as shown in Table 7-7. The buffer shall not be altered except as authorized by this Program.
Landslide Hazard Area | Standard Buffer Width (Feet)1 |
|---|---|
Marine Bluff – Feeder Bluff Exceptional | 150 feet |
Marine Bluff – Feeder Bluff or Feeder Bluff Talus | 100 feet |
Marine Bluff | 50 feet |
Other Landslide Hazard Areas (Nonchannel migration zone)2 | 50 feet |
1Measured from the top, toe and all edges of the landslide hazard areas.
2Refer to CCC 35.35.140(10) for channel migration zone standards.
(2) Buffer Condition. Buffers from landslide hazard areas shall be maintained in a predominantly well vegetated and undisturbed condition. Alterations to the buffer that are not associated with an allowed use or development shall be prohibited.
(3) Multiple Buffers. In the event that buffers for any shorelines and/or critical areas are contiguous or overlapping, the landward-most edge of all such buffers shall apply.
(4) Buffer Averaging. The Administrator may approve, without a shoreline variance, a reduction in the landslide hazard area buffer through buffer averaging contingent upon all of the following:
(a) Total area of buffer remains the same and the buffer has at least 150 trees and shrubs per acre or 55 percent aerial cover of trees and shrubs. The Administrator shall require planting or enhancement of the buffer to meet the stated density and/or cover targets if the existing vegetation conditions of the buffer do not meet the density and/or cover targets;
(b) The reduced portion of the buffer cannot exceed 40 percent of the buffer length;
(c) The reduced portion of the buffer must be at least 35 feet wide;
(d) A geotechnical report prepared by a qualified professional indicates that the development site will be stable for the life of the development, assumed to be at least 75 years, even if the buffer is reduced;
(e) For marine bluffs (includes feeder bluffs), the width of the reduced portion of the buffer must be equivalent to the estimated annual rate of erosion times 75 (plus any allowance for bank recession equal to largest documented landslide in the vicinity) as determined by a qualified professional pursuant to a geotechnical report;
(f) The proposed development incorporates stormwater management best management practices to address drainage, runoff and other slope stability issues; and
(g) All other requirements of this Program, including the critical area requirements of this chapter, are met.
(5) Buffer Reduction. Alterations of the buffer that do not meet the minimum standard buffer requirements or buffer averaging requirements of this section shall require a shoreline variance in accordance with Chapter 35.50 CCC.
(6) Hazard Tree Removal. Removal of a hazard tree may be allowed in the landslide hazard area or buffer when trimming is not sufficient to address the hazard. Where the hazard is not immediately apparent to the Administrator, the hazard tree determination shall be made after Administrator review of a report prepared by a qualified arborist or forester. Any tree removal shall be the minimum necessary to balance protection of the hazard area and its buffer with protection of life and property. To mitigate impacts of tree removal, the Administrator shall require planting of tree(s) or other vegetation, and may require leaving hazard trees taken down in buffer areas for habitat and/or woody debris recruitment along marine bluffs and riparian corridors.
(7) Increasing Buffer Widths.
(a) Feeder Bluff – Exceptional. The Administrator shall require a geotechnical report for all new development and uses within 200 feet of all top and toe of feeder bluffs – exceptional to assess and determine the need for increased buffers beyond the standard buffer widths in Table 7-7. Any increase of buffer shall be based on the findings of a geotechnical report.
(b) Other Landslide Hazard Areas. For other landslide hazard areas, the Administrator shall require a geotechnical report for new development and uses that may be at risk within 200 feet of the hazard area, even if located outside of the standard buffer width in Table 7-7, where a site visit shows active landslide activity or significant change in conditions based on recent geological events. Any increase of buffer shall be based on the findings of a geotechnical report.