A. 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. These are in addition to those standards outlined in title 11 of this code.
B. Lots: Lots on hillsides, with slopes of ten percent (10%) or more, are eligible for a twenty foot (20') front yard setback. Building permit applicants shall submit a plot plan showing the elevations of the lot at all corners.
If it is determined that a ten percent (10%) slope or greater exists on the property and the twenty foot (20') front yard setback is permitted, the minimum combined total of the front and rear yard setbacks shall be equal to what is normally required for the zone in which it is located.
C. Usable Area:
1. The slope of "usable area", as defined in subsection 10-14-9A3 of this chapter, shall not be greater than thirty percent (30%).
2. There shall be no excavation or cuts outside of the usable area.
3. All main and accessory buildings shall be built within the "usable area".
D. Faults: No residential structures shall be built on any identified faults or within their identified or approximated zones of deformation, or on any areas known to be an active landslide according to geotechnical analysis.
E. Drainage And Erosion:
1. Lots shall be arranged so as to ensure adequate setbacks from drainage channels;
2. Lots shall be arranged so as to ensure adequate "usable area" is located outside of the 100-year floodplain. No structures shall be allowed in the 100-year floodplain. The 100-year floodplain shall be determined using accepted engineering standards and approved by the city engineer;
3. Facilities for the collection of stormwater runoff shall be required to be constructed on the development site:
a. Such facilities shall be the first improvement of facilities constructed on the development site;
b. Such facilities shall be designed in accordance with accepted engineering standards so as to retain safely and adequately the maximum expected stormwater runoff for a 100-year storm (minimum), as per the South Weber City engineering standards, for a sufficient length of time so as to prevent flooding and erosion during stormwater runoff periods;
c. Such facilities shall be designed so as to divert surface water away from cut surfaces or sloping surfaces of a fill; and
d. Streets shall be designed to control and carry excess stormwater from the 100-year storm out of the development on street surfaces within the curbed area. Low points on streets shall not be allowed unless adequate drainage is provided.
F. Vegetation And Revegetation:
1. 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;
2. New plantings shall be protected with organic cover;
3. 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;
4. Vegetation shall be removed only when absolutely necessary (e.g., for the construction of buildings, roads, and filled areas); and
5. Vegetation shall be planted in all disturbed areas within three (3) months 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.
G. Grading, Cuts And Fills:
1. Exposed unstable surfaces of an excavation or fill shall not have a ratio steeper than one vertical to two horizontal (1:2);
2. All permanent fill shall be located so that settlements, sliding, or erosions shall not damage or cover streets, curb, gutter, sidewalk;
3. All fill and degrees of compaction shall comply with the standards of the adopted building code then in effect;
4. The top or bottom edges of slope caused by an excavation or fill up to ten (10) vertical feet shall be at least three (3) horizontal feet from the property line and street right of way lines;
5. The maximum vertical height of all cuts or fills shall be ten feet (10'), except in special circumstances where the city gives specific approval but shall not exceed twenty feet (20') in any case; and
6. 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.
7. Retaining walls may be constructed with the following provisions:
a. Structural retaining walls may be a part of the dwelling unit, if designed to function in that manner, and approved by the city building official.
b. Structural retaining walls must be designed by an authorized licensed professional engineer and approved by the city engineer.
c. Any wall less than four feet (4') in height (vertical) is considered "decorative" and not subject to approval by the city.
d. Any terracing of retaining walls shall be considered a structural retaining wall that must be designed by an authorized licensed professional engineer and approved by the city engineer.
e. Rock walls are considered "decorative" and cannot be used as structural retaining walls.
H. Streets And Ways: Streets, roadways, and private accessways shall follow as nearly as possible the natural terrain. The following additional standards shall apply:
1. 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 planning commission 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;
2. 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 twelve percent (12%) for a length not to exceed one hundred fifty feet (150') and a minimum width of ten feet (10');
3. Stub streets that are longer than the width or length of any adjacent single lot or one hundred fifty feet (150'), whichever is less, shall have an approved temporary turnaround at the end thereof;
4. 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.
I. Architectural Design:
1. Buildings proposed for construction in the South Weber sensitive lands overlay zone 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 required. Such materials as natural woods, brick (earth tones) and stone are considered to be most appropriate. Highly reflective glass is considered inappropriate.
2. The planning commission shall review the design and specified exterior materials and colors for all structures other than single-family dwellings. The building inspector shall review the plans of single-family dwellings with respect to colors, materials, etc. Building permits for such structures shall not be granted until building materials and colors have been approved by the reviewing authority.
J. Building Permit Bond: In addition to the performance bond, anything that is required by this chapter shall be bonded for. (Ord. 09-03, 8-11-2009)