02-17-2004 Planning Packet - Laserfiche WebLink

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•04.2983 Januaf7 30.2004 P«fc2 Background Please review ihe applicant’s letter of request. Bncfly. this property was granted hardcover variances in 2002 for a rebuild. The basis to allow the hardcov cr excesses w as primarily rcla’^ed to die perunsula shape of the lot, leaving about 1.5 acres of the 2-acre lot in the 0-75’ zone; and the placement of house and dnveway which allows for an unusually substantial area of lawn in the runoff flow path for infiltraiion. In order to avoid filling in the 0-75’ zone to accommodate the dnveway. the applicant was approved for a retaining w all adjacent to the dnveway. Now that the house is completed and final grades established, applicant has concerns about the necessary height of the retaining wall. From staffs perspective, safety IS the pnmary factor which suggests that elimmaring the wall may be appropnatc. The wall as approved was nght at the edge of the dri vew ay. with an immediate drop of 2 5'. then a 1:1 downslopc for another 34', w ith gradual slope after that. The driveway functionally is about 6’ above onginal grade at this point, and filling/grading would have stopped at the 75' setback line. This immediate grade change in an area th.it will have pedestnan traffic, children playing, etc. is less than ideal. The visual impacts of the wall would be primarily as it is viewed from the lagoon. Grading the slope and vegetating it w ould provide a softer and more natural view from the lagoon than a 64' long. 2 ’-6" hi gh w al I The driveway itself will not be very visible from the lagoon regardless of whether the wall is built. Applicant has suggested that creating a slope from the dnveway (clev. 942 ) to the esist.ng grade (934*) would eliminate 64* of retaining wall, or approximately 50-60 s.f. of hardcov cr. which w ould allow for a better situation in terms of ninoff. The trade-off is that rainfall that would have fallen on a relatively flat lawn surface at the base of the wall, will now fall on a slope and be somewhat more prone to run off than scak in during certain storm events. It’s probably an even trade. City code requires finish grades to be 3:1 or flaner in a situation such as this. Therefore, the 8' total drop translates to a 24' w idc slope. The dnveway is about 79' from the shoreline, so the toe of the f^11 area w ill be approximately 55 ’ from the shoreline, and the filled area w ill be about 80' in length. Total fill needed to do this is esti mated by staff at approximately 250 cubic yards of matenal [80 ft x (avg.7x24/2) / 27 ft per cy = 248 c.y.J. The fill w ill cover approximately 1900 s.f.; about 2/3 of this m the 0-75’ zone. Hard^gver. Hardcover in the 75-250’ zone was approved at 8.810 s.f. or 39 2'^ of the 75-2.50’ zone This was equivalent to 9.97t of the total lot area. Hardcover associated with the retaining wall is approximately 50-60 s.f.. so without it ihx 75-250’ hardcover will reduce to about S.750 s f or 38 9%. Hardcover Zone Area In Zone Allovied Hardcover RcsoL No. 4847 Propowd Hardcover 0-75 ’66.0X6 s.f.Osf. lOS-)Os.f 75-250 22.497 s f 8.810 sf. (39.2%)8.750sf. (38 9%)