(1) Scope. It is intended by this Section that the development standards and provisions, as set forth herein, shall be required in connection with all building and construction in the sensitive lands overlay area.
(2) Lots on hillsides. Lots on hillsides, with slopes of ten percent (10%) or more, are eligible for a twenty foot (20') front yard setback. The applicant shall submit a plot plan showing the elevations of the lot at all corners.
(3) Drainage and erosion.
(a) Lots shall be arranged so as to ensure adequate setbacks from drainage channels;
(b) Lots shall be arranged so as to ensure adequate buildable area is located outside of the one hundred-year flood plain. No structures shall be allowed in the 100 year flood plain;
(c) Facilities for the collection of storm water runoff shall be required to be constructed on the development site;
(i) Such facilities shall be the first improvement of facilities constructed on the development site;
(ii) Such facilities shall be designed in accordance with accepted engineering standards so as to retain safely and adequately the maximum expected storm water runoff for a one-hundred (100) year storm (minimum), as per the Layton City engineering standards, for a sufficient length of time so as to prevent flooding and erosion during storm water runoff flow periods; and
(iii) Such facilities shall be designed so as to divert surface water away from cut surfaces or sloping surfaces of a fill.
(iv) Streets shall be designed to control and carry excess storm water out of the development on street surfaces within the curbed area. Low points on streets shall not be allowed unless adequate drainage is provided.
(4) Vegetation and revegetation.
(a) All areas on development sites cleared of natural vegetation in the course of construction of off-site improvements shall be replanted with vegetation, which, when established, shall have characteristics of erosion control equal to or exceeding the original vegetation;
(b) New plantings shall be protected with organic cover;
(c) The use of persons or firms having expertise in the practice of revegetation (i.e., landscape architects or certified nurserymen) shall be employed to supervise the planning and installation of revegetation cover;
(d) Vegetation shall be removed only when absolutely necessary (e.g. for the construction of buildings, roads, and filled areas); and
(e) Vegetation shall be planted in all disturbed areas within three (3) weeks of the completion of off-site improvements. Such vegetation shall be of a perennial and low combustibility nature and shall be sufficient when established, to stabilize the soil.
(5) Grading, cuts and fills.
(a) Exposed unstable surfaces of an excavation or fill shall not have a ratio steeper than one (1) vertical to two (2) horizontal;
(b) All permanent fill shall be located so that settlements, sliding, or erosions shall not damage or cover streets, curb, gutter, sidewalk, or as provided in Subsection (5)(c);
(c) All fill and degrees of compaction shall comply with the standards of the adopted Building Code then in effect;
(d) The top or bottom edges of slope caused by an excavation or fill up to ten vertical feet (10') shall be at three horizontal feet (3') from the property line and street right-of-way lines;
(e) The maximum vertical height of all cuts or fills shall be ten feet (10'), except in circumstances where the Planning Commission gives specific approval; and
(f) All structures, except retaining walls or soil stabilization improvements, shall have a setback from the crest of the cut or base of the fill of a minimum distance equal to the depth of the fill or the height of the cut, unless a structurally sound retaining wall is built for the cut or fill slope. Retaining walls may be a part of the dwelling unit. Retaining wall design and construction must be approved by the Building Official.
(6) Streets and ways. Streets, roadways, and private access ways shall follow as nearly as possible the natural terrain.
The following additional standards shall apply:
(a) At least two (2) ingress and egress routes shall be provided for each subdivision or condominium project, in the long range development plans of the development unless it is determined by the City Engineer that it is not feasible due to topography or other constraints. If so determined, additional development requirements may be imposed in order to mitigate circumstances of a single access;
(b) Points of access shall be provided, giving access to all developed, partially developed, or undeveloped areas for emergency and firefighting equipment. Driveways located upon each lot extending from a public street shall have a maximum grade of eight percent (8%) and a minimum width of ten feet (10'). Driveways may have a maximum grade of up to twelve percent (12%) for a length not to exceed one hundred fifty feet (150'), unless approved by the City Engineer and City Fire Chief, and shall be of sufficient width and design to admit and accommodate firefighting equipment;
(c) Cul-de-sacs shall not exceed six hundred feet (600') in length and shall have a turn-around with a radius of fifty feet (50'). Fire access roads for future development that are longer than the width or length of one hundred fifty feet (150') or two (2) adjacent lots, whichever is less, shall have an approved temporary turn-around at the end thereof as prescribed in Section 18.24.070;
(d) Centerline curvatures shall not have less than a one hundred foot (100') radius on any curve street pattern;
(e) Variations of the street design standard developed to solve special hillside visual and functional problems may be presented to the Planning Commission for consideration. Examples of such variations may be the use of split roadways to avoid deep cuts, modifications of surface drainage treatments, or sidewalk design;
(7) Architectural design.
(a) Buildings proposed for construction in the Layton Sensitive Lands Overlay Zoning District shall be designed to be visually compatible with the natural beauty of the foothills and canyon areas. The use of building materials and colors that will blend harmoniously with the natural setting is encouraged. Such materials as natural woods, brick (earth tones), and stone are considered to be most appropriate.
(b) The Planning Commission shall review the design and specified exterior materials and colors for all structures other than single-family dwellings. Building permits for such structures shall not be granted until building materials and colors have been approved by the Planning Commission.
(8) Bond. In addition to the provisions requiring posting of a bond as set forth in the ordinances of Layton City, a bond, in a form acceptable to the City Council and City Attorney, may be required by the Planning Commission or City Council, to guarantee the completion of revegetation projects, the stabilization of grading, cut and fills, and other elements involved in the construction of such projects.
(9) Exceptions. Exceptions to the requirements and provisions as outlined in this Section may be approved by the City Council, provided that the developer or owner of such development site can demonstrate to the satisfaction of the City Council that the requested exceptions shall not be detrimental or injurious to the property or improvements adjacent thereto, or detrimental to the general well being of the neighborhood, or in violation of the stated purposes of this Chapter.
Ord. No.97-35, Recodified, 6/19/1997
Ord. No. 97-19, Enacted, 4/17/1997
Ord. No. 00-16, Amended, 5/18/2000
Ord. No. 04-69, Recodified, 12/16/2004
Ord. No. 13-17, Amended, 8/15/2013