Eugene Planning Commission <br />May 2, 2018 <br />Page 5 <br />"Soil creep is the downhill movement of near surface soil (usually the upper 2- to 3-feet) due to <br />gravity, freeze/thaw, and shrink/swell effects. The slow creep may cause a pistolbutting of tree trunks <br />during their early growth phase until substantial root mass and trunk strength is developed. Creep <br />is common on most hillsides and does not indicate gross landslide movement. Creep movement is <br />generally mitigated by modem foundation systems and control of soil moisture and temperature <br />under and around the residence to where the slow movement is unnoticeable over the typical lifespan <br />of a residence." <br />(Branch Engineering Geotechnical/Geological Investigation Rebuttal, March 20, 2018.) <br />The applicant's geotechnical engineer responded to the GeoSciences assessment by reiterating the <br />finding in the applicant's analysis that "[t]here are areas of gross land instability on the east side and <br />those were field mapped to the best of our ability for the planning level report. Mr. Schlieder's <br />interpretation of the LIDAR is simply that, an interpretation with no ground reconnaissance of the <br />site. The supposed landslide features that appear to encroach onto the northeast portion of the site <br />are just as likely to be erosional in nature if they exist at all." To respond to Dr. Schlieder's analysis <br />related to Floral Hill Drive, the applicant's engineer provides a detailed factual analysis to support <br />its conclusion that there is no indication of landslide movement in that area. <br />Neither the GeoSciences assessment nor the forester's assessment consider or respond to the <br />numerous, specific recommendations in the applicant's geotechnical investigation to minimize the <br />potential for slope failure. <br />2.a. Applicant's initial report and recommendations. <br />This portion of the code requires the applicant to present evidence that the proposed development <br />will not be a risk to public health and safety. The proposed PUD is located at the top of and in the <br />upper parts of a ridge in Eugene's South Hills, with residential development already present on three <br />sides below the proposed PUD. This means that inappropriate decisions made during development <br />within the PUD property have a disproportionate potential to affect nearby, already developed <br />properties. <br />In this context it must be considered that there are essentially no locations in the world for which a <br />case can be made that they are eminently "undevelopable" due to some geologic constraint. In every <br />case, it is theoretically possible to develop an engineering solution which would allow development <br />of the site without an increased risk to public health and safety. However, such development has <br />three requirements: <br />1. A thorough understanding of the geologic conditions at the site; <br />2. Development of appropriately engineered mitigation measures; and <br />3. Willingness to implement those mitigation measures at whatever cost. <br />