14 - Laserfiche WebLink

difference between the "last hill" approach and the 200-foot rule, as applied to Sunol Ridge. Figure 4: Illustration of Ridgelines All considered ridgelines per currently proposed method ter' .4,111104!v �.Y' ,- • _. _ R • - . „i .R ii - k� 4. Identify 100-Foot Vertical Setback. Measure PP prohibits development within 100 vertical feet of a ridgeline. For the mapping presented in this report, this setback is defined as the horizontal line measured 100 vertical feet below the ridgeline, which is then plotted on a topographic map. Note that in the Southeast Hills, there are many closely-spaced ridgelines, meaning that some of the ridges have overlapping 100-foot vertical setbacks. Similar to the rule regarding termination of a ridgeline, vertical setbacks also terminate at the boundary of the mapping area for the Southeast Hills. For purposes of mapping clarity, these 100-foot vertical setbacks were combined, allowing for a contiguous polygon setback area around the ridgelines in the Southeast Hills project area. Exhibit D is the resultant map of ridgelines and 100-foot vertical setbacks using the methodology described above. 5. Field-verify. After undertaking preliminary mapping of slopes, ridgelines, and vertical setbacks, staff visited and hiked through the Southeast Hills, generally focusing on the northern and western reaches closest to existing development. The primary purpose of the visit was to better understand the distinction between ridges and spurs on the landscape, and to confirm that all obvious ridges were identified as such on the mapping. After the field visit, staff made relatively minor adjustments to the mapping to better reflect the observed landforms. The final composite map, included as Exhibit E, shows areas protected by Measure PP (areas that contain slopes over 25 percent and/or are within the 100-foot vertical ridgeline setback area) and areas that would not be protected Mapping of Southeast Hills Planning Commission Page 8 of 10