Eugene Planning Commission <br />May 2, 2018 <br />Page 8 <br />2.b. "Numerous, specific recommendations to minimize the potential for slope failure" <br />Branch Engineering's geotechnical investigation report contains recommendations on pages 8, 9, 10, <br />and 11. The recommendations that come closest to addressing some portion of the known landslide <br />risk are: <br />"Prior to construction of roadways, driveways, or residential foundations within the area <br />delineated on Figure 1 as "Area of recommended exclusion for proposed construction of <br />public or private streets and zone of special consideration for design and construction of <br />residential foundations" specific plans should be reviewed by a qualified professional to <br />ensure that the proposed work is feasible given the topographic constraints of the site"" <br />"We anticipate that as structures are built on the lots within or adjacent to the area delineated <br />as the "Area of recommended exclusion for proposed construction of public or private streets <br />and zone of special consideration for design and construction of residential foundations" as <br />shown on Figure-1 that hillside foundation systems such as piers or pilings will be required. <br />Specific foundation plans within this are should be reviewed on a case by case basis by <br />qualified professionals prior to design and constructioni14 <br />"...Fill slopes constructed of compacted earth shall not exceed a steepness of 1.5:1 (H:V). <br />If steeper slopes are required, we recommend that structures such as retaining walls are <br />considered. Cut slopes shall not exceed 1.5: 1(H:V) in steepness for excavation into the clay <br />and weathered sandstone material. If tough sandstone is encountered in cuts requiring rock <br />hammers for removal the geotechnical engineer may visit the site and approve steeper cuts <br />to be constructed based on subsurface conditions. Surface water shall be directed away from <br />the top of slopes and slope faces protected from erosion."15 <br />Other recommendations on the 3.5 pages devoted to recommendations have little or no bearing on <br />slope stability. Similarly, the "Geotechnical Specifications, General Earthwork" in Appendix B of <br />the Branch document contain no recommendations with any bearing on slope stability. <br />Of the three recommendations that peripherally address the slope stability of the site, the first and <br />second are essentially identical. Please note that the recommendation is to "review" the plans (to <br />ensure that the work is feasible due to topography). No direct mention of slope stability is made. <br />13 Branch Engineering Geotechnical/Geologic Investigation Capital Hill PUD, 2/6/17, p 8, 3rd paragraph <br />14 Branch Engineering Geotechnical/Geologic Investigation Capital Hill PUD, 2/6/17, p 9, 3rd paragraph <br />15 Branch Engineering Geotechnical/Geologic Investigation Capital Hill PUD, 2/6/17, p 10, 2nd paragraph <br />