B. Requirements and Applicability.
1. Coastal Bluff Areas.
a. Geologic studies as set forth by the county grading standards shall be required as a part of the permit application for new construction within the area of demonstration to determine:
i. Their suitability for development and
ii. The necessary setbacks and/or yards required to avoid or reduce hazards associated with bluff failure.
b. The area(s) of demonstration of stability includes the base, face and top of all bluffs and cliffs. The extent of the bluff top considered should include the area between the face of the bluff and a line described on the bluff top by the intersection of a plane inclined at a twenty-degree angle from horizontal passing through the toe of the bluff or cliff, or fifty feet inland from the edge of the cliff or bluff, whichever is greater.
c. Where adequate geologic evaluation, historic evidence and/or adequate protective works already exist and demonstrate stability, the county may designate a greater area of demonstration, or exclude development entirely, in known areas of high instability.
d. Data submitted shall be utilized to require the provision of feasible mitigation(s) as a part of development such as building setbacks or engineered structures.
2. Tsunami and Coastal Erosion Areas.
a. Any development proposed adjacent to identified tsunami run-up and/or coastal erosion area shall re-quire as a part of the permit application:
i. An assessment of the rates of coastal re-treat, in the case of bluffs, a detailed examination of underlying geology by a registered geologist or engineering geologist and/or
ii. An analysis of the potential for tsunami run-up.
b. Critical coastal erosion areas are:
i. The coastal area between Point St. George and Crescent City, extending approximately 2.3 miles north from the city boundary.
c. Critical tsunami run-up areas are:
i. Those southern Crescent City areas delineated as tsunami run-up on the General Plan Coastal Element Land Use Constraint-Hazards Map.
d. Data submitted shall be utilized to require the provision of feasible mitigation(s) as a part of development such as building setbacks, minimum-first-floorelevations or engineered structures.
e. To the extent practicable, critical facilities, such as hospitals, schools, utility installations (other than service lines) and communication centers should not be sited in areas susceptible to tsunami inundation. Where it is deemed essential to do so for the public welfare, these structures should be sited, designed and constructed with mitigations.
3. Slope Failure Risk Areas.
a. Geologic studies as set forth by the county grading standards shall be required as a part of any application for development and shall assess the stability of the site under both normal and seismic conditions as well as recommended mitigations.
b. Slope failure risk areas are as identified by the Seismic Safety and Safety Element of the Del Norte County General Plan.
c. Data submitted shall be utilized to require the provision of feasible mitigation(s) as a part of development such as building setbacks or engineered structures.
(Ord. 83-03(part))