Development Adjacent to Coastal Bluffs. Development adjacent to coastal bluffs shall minimize hazards to owners, occupants, property, and the general public; be environmentally sensitive to the natural coastal bluffs; and protect the bluffs as a scenic visual resource. The minimum setback from the bluff edge of a coastal bluff shall be established by the underlying zoning district. However, in no case shall the minimum setback be less than 25 feet or one which provides for 50 years of erosion, whichever is most restrictive.
In addition, should the geotechnical report indicate bluff stabilization is required to ensure proposed development is safe from a threat of erosion and bluff failure for fifty years, additional setbacks will be required. Any approved slope stabilization measures shall be the least environmentally damaging feasible alternative and shall be designed to minimize alteration of the bluffs and be subordinate to the natural character of the bluffs.
Development setbacks from coastal bluff edges may not be the same due to varying geologic conditions and environmental conditions. The following provisions detail the items required for filing, the means by which coastal bluff edges are measured, criteria for review, development standards, and the potential development that may be permitted within the coastal bluff setback area.
(1) Coastal Bluff Edge Measurement.
(A) The applicant shall provide an aerial photograph and contour map of the site clearly delineating the current coastal bluff edge, existing topography and the outline of the development proposed.
(B) The applicant shall provide a geotechnical report, prepared within one year of the date of the application submittal, which specifically addresses the coastal bluff edge and delineates the bluff edge on a graphic exhibit on both the grading plan and site plan. The report shall specifically address the methodology used to support the conclusions of the report.
(C) The Director of Community Development and Director of Public Works or their designee shall conduct an on-site survey of the property and compare the geotechnical report's conclusions with that of actual on-site terrain and bluff top patterns.
(2) Criteria For Review. At a minimum, the following will be required for each application for development adjacent to coastal bluff edges:
(A) Development plans shall be prepared and wet stamped by a State Certified Engineering Geologist knowledgeable in coastal engineering and engineering geology.
(B) A geotechnical report shall address the factors which directly or indirectly cause, promote, or encourage bluff erosion or failure either on site or on adjacent properties, and the measures to control these factors. The report shall include, but shall not be limited to, the following information:
1. Bluff geometry, site topography, and any other condition which may affect the site.
2. Historic, current, and foreseeable bluff erosion. A minimum of 50 years of historic erosion and 50 years of future erosion should be analyzed.
3. Geologic conditions including, but not limited to, soils, sediment, bedrock, drainage patterns, and structural features such as fault lines and joints. Soils borings to bedrock and the limits and depth of alluvial removal shall be addressed to the satisfaction of the Director of Public Works.
4. Evidence of past and potential landslides and the implication of such conditions on the structural integrity of the proposed development as well as the proposed development's potential effect on landslide activity.
5. Impact of construction activity on the stability of the site and adjacent area. This shall include, but not be limited to, remedial grading, the impact of grading machinery, or other vibration inducing factors on the bluff stability.
6. Ground and surface water conditions or variations caused by the development, such as the alteration in surface/subsurface drainage, irrigation systems, and proposed drains and subdrains.
7. Mitigation measures proposed to be used to ensure minimized erosion problems during and after construction.
8. Any other facts that might affect slope stability, including but not limited to the effects of marine erosion on coastal bluffs, and related mitigation measures for potential impacts.
9. Any proposed development, either main structures or minor development, shall be addressed in the report. Said structures and development shall be evaluated with respect to impact on the stability of the bluff to ensure that structures and development are reasonably safe from failure and erosion given a minimum 50-year physical life.
10. Any other information as deemed necessary by the Director of Community Development or Director of Public Works.
11. A bibliography of all information sources, including, but not limited to, dates of site visits.
(3) Development Standards.
(A) Drainage. All surface and subsurface run-off shall be directed to a public street or an approved drainage facility to the satisfaction of the Director of Public Works. Transportation of said run-off may require area drains, roof drains, reductions in grading, appropriate pumping mechanisms, and other similar measures. Where feasible, said run-off shall be directed to sewer systems rather than storm drains which lead directly to the ocean.
(B) Landscaping. All landscaping shall be native or drought tolerant which minimizes irrigation requirements, and reduce potential slide hazards due to over watering. Irrigation and the use of turf grass, ice plant and similar shallow-rooted plants within the bluff setback shall be specifically prohibited on blufftop developments. Landscaping shall be maintained and installed so as to ensure that, during growing stages as well as at maturity, the landscaping will not obstruct public views.
(4) Requirements for Setback Deviation. A State Licensed Civil Engineering Geologist shall prepare a site specific geotechnical and soils report to address and explain any proposed deviation from the minimum setbacks from the coastal bluff edge in the Zoning Map, and the Draft Dana Point General Plan Coastal Erosion Technical Report dated July 11, 1990. The report shall include:
(A) An explanation and calculation of the deviations, if any, in the setback from the coastal bluff edge.
(B) If caissons are not recommended, the report shall explain why caissons are not needed. If caissons are recommended in the report, the following additional information shall be provided:
1. Indicate the angle of repose.
2. Depth of caisson required for the structure and limits of caissons.
(C) Requirements for Setback Deviation. Should an analysis of the geotechnical report conclude that a greater or lesser setback may be necessary than that required by this Code, the Planning Commission can make a finding that it is in the interest of the public safety to approve an additional or lesser setback as recommended. However, in no case shall a setback of less than 25 feet or less than 50 years of bluff erosion, whichever is most restrictive, be permitted.
(5) Permitted Development within the Coastal Bluff Edge Setback. Precautions are required to ensure that the integrity of the bluff is not threatened. Development within the coastal blufftop setback area shall minimize landform alteration, be subordinate to the natural character of the bluff, and is limited to structures that may include retaining and non-retaining walls, fences, and drought-tolerant landscaping which conform to the setback requirements of this Chapter. Swimming pools and sunken spas are prohibited within the setback area. Additional setbacks shall be required if recommended in a geotechnical report submitted for the minor development.
Minor development and improvements are defined as:
(A) Those generally not requiring a building or grading permit and not attached to the main structure; and
(B) Those developments which protect natural resources or ensure public safety such as fences and low walls.
A Coastal Development Permit pursuant to Chapter 9.69 shall be required prior to any minor development. Minor development may only be approved if the approved geotechnical reports support such development and conclude that the development will not have an impact on bluff stability. All minor development shall be environmentally sensitive to the natural bluff line and public view. |
Grading on the coastal bluff shall be kept to a minimum. Raising of the natural grade shall be limited to that level needed to provide a maximum of 1% of fall to the existing top of curb in the street in order to facilitate piping of all bluff drainage to the street by gravity. |
A study which details the potential impact of any proposed grading on the coastal bluff may be required at the discretion of the Director of Community Development or the Director of Public Works as the circumstances of the individual lot warrant. The study shall be prepared to address the impacts identified by the City to the satisfaction of the Director of Community Development and/or the Director of Public Works. |
(6) Development at the Base of Coastal Bluffs. Development proposed at the base of coastal bluffs shall be required to submit appropriate geotechnical reports which provide a detailed assessment of the ultimate stability of the bluffs above the subject site. The report(s) shall document the ultimate profile (section) of the bluff face, delineate the buildable portion of the site and shall include recommendations for adequate protective structures for the project as well as recommendations for alternatives which do not require landform alteration of the bluff face nor bluff stabilization. The report(s) shall address all topics relevant to the geologic condition of the subject site and adjacent bluffs and shall be prepared to the satisfaction of the Director of Public Works. Proposals for shoreline protective devices at the base of coastal bluffs shall be consistent with the requirements of Section
9.27.030(f) below.
(7) Development on the face of Coastal Bluffs. New private staircases, the replacement of 50% or more of existing private staircases, or additions to/expansion of existing private staircases, which descend down bluff faces shall be prohibited. Public staircases down bluff faces shall only be permitted if geologic instability would not result, if landform alteration would be minimized, and the staircase would be visually subordinate to the natural character of the bluff face.