(A) Development. Development in the city's coastal zone shall:
(1) Minimize risks to life and property in areas of high geologic and flood hazard;
(2) Assure stability and structural integrity;
(3) Neither create nor contribute significantly to erosion, geologic instability, or destruction of the site or surrounding area.
(B) High density development in flood hazard areas. High density residential and other high occupancy development, including new hospitals, schools, residential development with a gross density of eight units per acre or more, office buildings 10,000 square feet in size or larger, or visitor-serving structural developments 5,000 square feet in size or larger, shall not be located in flood hazard areas, as designated on the Federal Emergency Management Agency Flood Insurance Rate Maps, dated June 1, 1982, unless they are constructed with a finished foundation that extends above the 100-year flood level and meet all applicable drainage requirement of the Local Coastal Program. Other development in flood hazard areas shall incorporate mitigation measures that minimize the potential for flood damage, including development siting and use of flood proofing techniques and materials, consistent with other land use plan policies.
(C) Elk River, Humboldt Bay, Eureka Slough. Development on or near the shoreline of Elk River, Humboldt Bay, and Eureka Slough shall neither contribute significantly to, nor be subject to, high risk of damage from shoreline erosion over the life span of the development. The city shall establish a benefit assessment district for all property adjoining and protected from flooding by the Jacobs Avenue dike. A repair and maintenance program shall be developed and implemented, consistent with Policy 5.8 and Policy 5.14.
(D) Development in areas of liquefaction. For all high density residential and other high occupancy development, as defined in Policy 7.2, located in areas of significant liquefaction potential, the city shall, at the time of project application, require a geology and soils report which conforms to the following requirements:
(1) The report shall be prepared by a registered geologist, professional civil engineer with expertise in soil mechanics or foundation engineering, or by a certified engineering geologist, and shall consider, describe, and analyze the following:
(a) Geologic conditions, including soil, sediment, and rock types and characteristics in addition to structural features, such as bedding, joint and faults;
(b) Evidence of past or potential liquefaction conditions, and the implications of such conditions for the proposed development;
(c) Potential effects of seismic forces resulting from a maximum credible earthquake;
(d) Any other factors that might affect the development.
(2) The report shall also detail mitigation measures for any potential impacts and outline alternative solutions. The report shall express a professional opinion as to whether the project can be designed so that it will neither be subject to nor contribute to significant geologic instability throughout the life-span of the project. The report shall use a currently acceptable engineering stability analysis method and describe the degree of uncertainty of analytical results due to assumptions and unknowns.
(E) Cliffs, bluff tops, gulch faces. Alteration of cliffs, bluff tops, and gulch faces or bases by excavation or other means shall be prohibited except to protect existing structures. Permitted development shall not require the construction of protective devices that would substantially alter natural landforms.
(F) Shoreline erosion areas. For all development proposed within areas subject to significant shoreline erosion, the city shall, prior to project approval, require a geology and soils report which conforms to the following requirements:
(1) The report shall be prepared by a registered geologist, professional civil engineer with expertise in soil mechanics of foundation engineering, or by a certified engineering geologist, and shall consider, describe and analyze the following:
(a) Site topography, extending the surveying work beyond the site as needed to depict unusual conditions that might affect the site;
(b) Historic, current and foreseeable shoreline erosion, including investigation of recorded land surveys and tax assessment records in addition to the use of historic maps and photographs where available and possible changes in shore configuration and sand transport;
(c) Geologic conditions, including soil, sediment and rock types and characteristics in addition to structural features, such as bedding, joint and faults;
(d) Impact of construction activity on the stability of the site and adjacent area;
(e) Potential for erosion of site and mitigating measures to be used to ensure minimized erosion problems during and after construction;
(f) Effects of marine erosion on shoreline areas;
(g) Potential effects of seismic forces resulting from a maximum credible earthquake; and,
(h) Any other factors that might affect slope stability.
(2) The report shall evaluate the off-site impacts of development and the additional impacts that might occur due to the proposed development. The report shall also detail mitigation measures for any potential impacts and outline alternative solutions. The report shall express a professional opinion as to whether the project can be designed so that it will neither be subject to nor contribute to significant geologic instability throughout the lifespan of the project. The report shall use a currently acceptable engineering stability analysis method and describe the degree of uncertainty of analytical results due to assumptions and unknowns.
('63 Code, § 10-5.2943) (Ord. 417-C.S., passed 12-6-84; Am. Ord. 519-C.S., passed 8-26-90) Penalty, see § 150.999