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Kittitas County,WA <br /> § 17A.06.010 CRITICAL AREAS § 17A.06.020 <br /> CHAPTER 17A.06 <br /> GEOLOGICALLY HAZARDOUS AREAS <br /> § 17A.06.010. Purpose and intent. <br /> The purpose of this Chapter is to protect human life and safety,prevent damage to structures and property, <br /> and minimize impacts to water quality and fish and wildlife caused by geologic hazards. <br /> (Ord. 2021-016,2021) <br /> § 17A.06.020. Designation,classification, and mapping. <br /> 1. Designation. Lands classified as landslide, erosion(including channel migration zones), alluvial fan, <br /> seismic, and mine hazard areas, are hereby designated as geologically hazardous areas. <br /> 2. Classification. <br /> a. Potential landslide hazard areas.Landslide hazard areas shall include areas potentially subject to <br /> landslides based on a combination of geologic, topographic, and hydrologic factors. They <br /> include any areas susceptible because of any combination of bedrock,soil,slope(gradient),slope <br /> aspect,structure,hydrology,or other factors.Potential landslide hazard areas include but are not <br /> limited to the following areas: <br /> i. Areas of historic failures; <br /> ii. Areas designated as quaternary slumps, earth-flows, mudflows, or landslides on maps <br /> published by the U.S. Geological Survey or Washington State Department of Natural <br /> Resources; <br /> iii. Areas with all three(3) of the following characteristics: <br /> 1. Slopes steeper than fifteen percent(15%); <br /> 2. Hillsides intersecting geologic contacts with a relatively permeable sediment <br /> overlying a relatively impermeable sediment or bedrock; and <br /> 3. Springs or groundwater seepage; <br /> iv. Areas that have shown movement and/or are underlain or covered by mass wastage debris; <br /> V. Slopes that are parallel or sub-parallel to planes of weakness (which may include but not <br /> be limited to bedding planes, soft clay layers,joint systems,and fault planes)in subsurface <br /> materials; <br /> vi. Slopes having gradients steeper than eighty percent (80%) subject to rock fall during <br /> seismic shaking; <br /> vii. Areas that show evidence of, or are at risk from snow avalanches; and <br /> viii. Any area with a slope of forty percent (40%) or steeper and with a vertical relief of ten <br /> (10) or more feet except areas composed of competent bedrock. A slope is delineated by <br /> establishing its toe and top and measured by averaging the inclination over at least ten(10) <br /> feet of vertical relief; <br /> ix. Potentially unstable slopes resulting from river erosion or undercutting; <br /> Downloaded from https:Hecode360.com/KI6857 on 2025-05-15 <br />