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<br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />CITY OF ORONO <br />RESOLUTION OF THE CITY COUNCIL <br /> <br />NO. 7589 <br /> <br /> <br />3 <br /> <br />CONDITIONAL USE PERMIT ANALYSIS: <br /> <br />The City Council may approve a CUP for the construction of retaining walls as long as the <br />walls are: <br />B1. Designed to correct an established erosion problem; the applicant’s landscape <br />design was developed to directly address an ongoing erosion problem that had been <br />affecting the stability of the shoreline and bluff line. The erosion was caused by <br />surface water runoff, natural wave action, incorrectly installed riprap, and ice heaves, <br />which had begun to undermine the soil and vegetation near the water’s edge and <br />bluff line. To correct this, the design included erosion control measures such as <br />deep-rooted native plants, erosion control fabric, and slope stabilization techniques <br />with the staircase and boulder retaining walls. These improvements were intended to <br />stop further erosion, help restore the health of the shoreline and preserve the roots <br />of trees that are exposed. This criterion has been met; and <br /> <br />B2. Suitable given the demonstrated need; A global stability analysis by Ronald W. Vickery, <br />PE was provided. He further notes that it was necessary to correct the shoreline with a <br />3:1 slope with large rip rap toe boulders. Boulders were also necessary to support the <br />stairway to the lake shore to help in stabilizing the bluff and protect as many trees as <br />possible. The results of the global stability analysis indicated an overall global stability <br />factor of safety of 1.378, which is over the industry standard factor of safety of 1.3. <br />Without the retaining walls, this factor of safety would be less than 1.3. Therefore, the <br />engineer indicates that the retaining walls and the stair system will greatly aid in the <br />stabilization of the slope. This criterion has been met; and <br /> <br />B3. Designed by a registered engineer or landscape architect, depending on the project <br />scope; the Applicant has provided a revised retaining wall design from a registered <br />engineer which matches the submitted plans. This criterion has been met; and <br /> <br />B4. Designed to be the minimum size necessary to control the erosion problem. The <br />engineer’s revised plan was to be as minimal and natural-looking as possible. It <br />includes only what is necessary to stabilize the shoreline and bluff line to prevent <br />further erosion. Native plants were chosen to hold soil in place and for their ability to <br />blend into the natural surroundings. Less than 4’ tall boulder walls were used in <br />areas where native plants would not have been enough to prevent further erosion. <br />No unnecessary structures were installed in the landscape, and every effort was <br />taken to preserve the natural view and character of the lakeshore. This criterion <br />has been met. <br /> <br />302