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<br /> <br />Kittitas County Shoreline Master Program <br />Chapter 5 75 <br />March 7, 2016 <br />Kittitas County Board of County Commissioners Shoreline Master Program Adopting Ordinance <br />Kittitas County Shoreline Master Program Exhibit A | March 2016 | Page 75 of 339 <br /> <br />a. Areas of historic failures, such as: <br />i. Those areas delineated by the Natural Resource Conservation Service <br />(NRCS) as having a “severe” limitation for building site development; or <br />ii. Those areas mapped as landslides, as having a liquefaction susceptibility, <br />or having a NEHPR seismic site class of A through D on the most current <br />Washington State Department of Natural Resources Division of Geology <br />and Earth Resources natural hazards web based map; or <br />iii. Areas designated as quaternary slumps, earth-flows, mudflows, lahars, or <br />landslides on maps published by the U.S. Geological Survey or Washington <br />State Department of Natural Resources Division of Geology and Earth <br />Resources. <br />b. Areas with all three (3) of the following characteristics: <br />i. Slopes steeper than fifteen percent (15%); <br />ii. Hillsides intersecting geologic contacts with a relatively permeable sediment <br />overlying a relatively impermeable sediment or bedrock; and <br />iii. Springs or groundwater seepage. <br />c. Areas that have shown movement during the Holocene epoch (from 10,000 <br />years ago to the present) or which are underlain or covered by mass wastage <br />debris of this epoch; <br />d. Slopes that are parallel or sub-parallel to planes of weakness (such as bedding <br />planes, joint systems, and fault planes) in subsurface materials; <br />e. Slopes having gradients steeper than eighty percent (80%) subject to rock fall <br />during seismic shaking; <br />f. Areas potentially unstable as a result of rapid stream incision, stream bank <br />erosion, and undercutting by wave action, including stream channel migration <br />zones; <br />g. Areas that show evidence of, or are at risk from snow avalanches; <br />h. Areas located in a canyon or on an active alluvial fan, presently or potentially <br />subject to inundation by debris flows or catastrophic flooding; and <br />i. Any area with a slope of forty percent (40%) or steeper and with a vertical relief <br />of ten (10) or more feet except areas composed of bedrock. A slope is delineated <br />by establishing its toe and top and measured by averaging the inclination over at <br />least ten (10) feet of vertical relief. <br /> <br />3. Classification: Erosion hazard areas – areas containing soils that may experience <br />significant erosion, including: <br />a. Slopes forty percent (40%) or steeper with a vertical relief of ten (10) or more <br />feet, except areas composed of consolidated rock. <br />b. Concave slope forms equal to or greater than fifteen percent (15%) with a vertical <br />relief of ten (10) or more feet, except areas composed of consolidated rock. <br />c. Channel migration zones: Areas within which the stream channel can reasonably <br />be expected to migrate over time as a result of normally occurring hydrological