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<br /> <br />54 <br /> <br />documented in a geologically hazardous area risk assessment and/or geotechnical <br />report; <br />f. The proposed alterations will not adversely impact other critical areas; and <br />g. Structures and improvements are designed to minimize alterations to the erosive <br />soils and slopes. <br />2. Channel Migration Zones. If County maps or consultation by the Director with qualified <br />professionals or agencies with expertise indicate that a potential channel migration zone <br />hazard exists on or adjacent to a proposed development site, the applicant shall either: <br />a. Locate the proposed development outside of an already defined channel migration <br />hazard area as indicated on the map; or <br />b. Submit a Channel Migration Zone Report, as described in KCC 17A.06.100 prepared <br />by a qualified geologist, or engineering geologist, or professional engineer, licensed <br />in the state of Washington with experience in analyzing channel response in the <br />fluvial systems of the Pacific Northwest. <br />3. Permitted Alterations and Development in Channel Migration Zones. The following <br />alterations and development shall be allowed as specified below and previous sections: <br />a. Surface Water Discharge. Discharge of surface water, provided there are no other <br />alternatives for discharge. The pipe shall be located on the surface of the ground and <br />be properly anchored so that it will continue to function under erosion conditions and <br />not create or contribute to adverse effects on downstream critical areas. <br />b. Utility Lines. Utility lines, when no feasible location is available. Above-ground lines <br />shall be anchored and/or designed so that it will not preclude or interfere with <br />channel migration. Below ground lines shall be of sufficient depth as to not be <br />affected by future channel migration. <br />c. Public Roads, Bridges, and Trails. Public roads, bridges, and trails when no <br />feasible alternative alignment is available. Facilities shall be designed such that the <br />roadway prism and/or bridge structure will not be susceptible to damage from active <br />erosion. <br />d. Stream Bank Stabilization. Stream bank stabilization may be permitted subject to <br />all of the standards listed in KCC 17A.04.050. <br />4. CMZ Buffers or Setbacks. Based upon the results of the channel migration zone <br />assessment, the Director shall prohibit or limit use or development within a channel migration <br />zone and may require a setback or a buffer of undisturbed natural vegetation from the edge <br />of the channel migration zone in accordance with the following: <br />a. The size of the setback or buffer shall be based on the findings of a qualified <br />engineer, engineering geologist, or geologist, licensed in the state of Washington, <br />and shall protect critical areas and processes and minimize the risk of property <br />damage, death, or injury resulting from channel migration; <br />b. The buffer shall include the area subject to bank failure as a result of erosion; and <br />c. If the designated buffer lacks adequate woody vegetation, the Director shall have the <br />authority to require vegetation enhancement or other measures to improve natural <br />channel processes and large wood recruitment. <br /> <br />17A.06.060 Alluvial Fan Hazard Standards <br />1. Permitted Alteration and Development. Alluvial fan hazards will be determined by County <br />maps, LIDAR, and aerial photography. The following alterations and development may be <br />allowed in alluvial fan hazard areas, after accounting for restrictions defined by other critical <br />area regulations, when all reasonable measures have been taken to minimize risks and other <br />adverse effects associated with alluvial fan hazards, and when the amount and degree of <br />alteration are limited to the minimum needed to accomplish the alteration or development: <br />a. Roads, Utilities, Bridges, and Other Infrastructure. Roads, utilities, bridges, and <br />other infrastructure when located and designed to prevent adverse impacts on critical