RES 17-981 - Laserfiche WebLink

of these spurs fell within the horizontal area already encompassed within the 100-foot vertical setback (and exhibited the drainage-derived topography described above), they were not considered ridgelines. This approach eliminated from Measure PP spurs and secondary ridges subservient to the main ridgelines (see Figures 3 and 4 for examples of ridgelines and spurs). Pursuant to the Planning Commission's recommendation, staff evaluated alternative approaches to defining spurs. In general, the geomorphic processes (primarily erosion) that created spurs resulted in spur landforms that are very steeply-sloped. As seen in Attachment 6, most spurs in the Southeast Hills contain slopes greater than 25 percent. While some spurs contain small areas of lesser slopes, it would be difficult to build multiple structures in these areas (or to construct roads to access these structures) due to geotechnical concerns. In addition, because spurs usually fall steeply to the valley floor, they are largely encompassed within the 100-foot vertical ridgeline setback. For these reasons, spurs are largely excluded from substantial development by nature of Measure PP's restrictions on developing steep slopes and areas within 100 vertical feet of a ridgeline. However, an alternate method could involve establishing a length threshold beyond which spurs would be considered ridgelines and subject to Measure PP. For instance, spurs extending more than 500 feet in length from the primary ridge could be considered ridgelines and subject to Measure PP. This approach would not materially change the mapping presented in this report, which shows that the vast majority of the Southeast Hills is subject to Measure PP considerations. Figure 2: Slopes on Longview Drive Percent Slope -17-22% -12-22% -5.13% --4.7% " " " ts 111° e Aftr .• t.w