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2. In addition to the City's Critical Areas Map, the following publicly available <br />mapping information may be used to determine appropriate designations: <br />a. For historic landslides, areas designated as quaternary slumps, <br />earthflows, mudflows, or landslides on maps published by the U.S. Geological Survey or <br />the WDNR Division of Geology and Earth Resources, <br />b. For potential or historic landslides, those areas mapped by the WDNR <br />(slope stability mapping) as unstable (U or Class 3), unstable old slides (UOS or Class <br />4), or unstable recent slides (URS or Class 5); <br />c. For soil characteristics, the U.S. Department of Agriculture's Natural <br />Resources Conservation Service (NRCS) Official Soil Survey Data; and <br />d. For general instability, those areas mapped by the NRCS as having a <br />significant limitation for building site development. <br />C. BUFFERS. The buffers for areas of potential geologic instability are intended to: <br />areas; <br />Minimize long-term impacts of development on properties containing critical <br />2. Protect critical areas from adverse impacts during development; <br />3. Prevent loading of potentially unstable slope formations; <br />4. Protect slope stability; <br />5. Provide erosion control and attenuation of precipitation surface water and <br />stormwater runoff; and <br />6. Reduce loss of or damage to property. <br />D. Each development proposal containing or threatened by an area of potential <br />geologic instability Class 2 or higher shall be subject to a geotechnical report pursuant to <br />the requirements of TMC Chapter 18.45.040.C. The geotechnical report shall analyze and <br />make recommendations on the need for and width of any setbacks or buffers necessary <br />to achieve the goals and requirements of this chapter. Development proposals shall then <br />include the buffer distances as defined within the geotechnical report. <br />Section 32. TMC Section 18.45.130 is hereby reenacted to read as follows: <br />18.45.130 Areas of Potential Geologic Instability Uses, Exemptions, Alterations <br />and Mitigation <br />A. GENERAL. The uses permitted in the underlying zoning district may be <br />undertaken on sites that contain areas of potential geologic instability subject to the <br />standards of this section and the recommendations of a geotechnical study. <br />w:\Legislative Development\Critical Areas update 2-25-20 <br />MD:bjs Review and analysis by Barbara Saxton Page 35 of 87 <br />