22 ATTACHMENT 05 - Laserfiche WebLink

Grading Plan. A 20-foot wide access easement and utility easement would be created on the eastern edge of the development. This 20-foot wide easement includes a 16-foot asphalt concrete pavement serving as the private road as well as the access for emergency vehicles. The proposed road would start at an elevation of 426 feet climbing up the slope from a 3% incline to a 15% incline until it reaches the hammerhead end at an elevation of 500 feet. Retaining walls would be constructed on both sides the road. The proposed retaining wall height would vary from four to nine feet on the east side and is four feet on the west side. The existing grade at the proposed Lot 1 varies from an elevation of 450 feet at the northeastern portion of the lot to an elevation of 480 feet at the southwestern-most portion of the lot. The lot slopes up naturally southwesterly. As shown on the slope map in Exhibit B, the slope gets gentler in the southern portion of the lot than the northern portion of the lot. As such, a building envelope is proposed in the less steep portion of the lot for all structures to be constructed for Lot 1. In order to create the building pad, the grading plan shows a 2:1 cut design to remove approximately 2,400 cubic yards of dirt for a split-pad design. The building pads would be located at elevations of 460 feet and 470 feet. The proposed Lot 2 would be located to the south of the proposed Lot 1. The grade on Lot 2 varies from an elevation of 500 feet near the end of the private road to an elevation of 530 feet at the western property line. The proposed building pad would be located at an elevation of 515 feet. Due to the existing topography of the site and non-split-pad design, grading on Lot 2 would be comparably more than grading on Lot 1. Both Alternative 1 and Alternative 2 site layouts for Lot 2 would have an elevation variation of 480 feet near the end of the private road to an elevation of 530 feet at the western property line. Both alternative site layouts would need more grading as the proposed building pads would be located at an elevation of 510 feet for Alternative 1 and at 500 feet for Alternative 2. Staff believes that the proposed grading would afford a building area that is adequate in size to accommodate future buildings for both lots. However, should future homeowners request to modify the building pad elevation(s), a modification to the PUD development plan may be required as determined by the Director of Community Development. Staff has added a condition of approval to address this item. Overall, staff finds the grading plan to be acceptable. Utility Plan. The applicants submitted a preliminary utility plan for Commission's review. The preliminary utility plan shows an 18-inch storm drain would be proposed following the alignment of the private roadway. This storm drain line is sized adequately to carry the additional stormwater runoff from the future homes on both lots. Water and sanitary sewer lines would be extended from the existing City lines in Silver Oaks Court up the private road to serve the future homes. All new on-site utilities required to serve the proposed development will be installed underground in a joint utility trench. In addition, a bio-retention facility is proposed near the northern end of the private road. Two fire hydrants are proposed; one PUD-84 Planning Commission Page 14 of 23