11-6 Development Standards

11-6.1. These development standards govern all proposed development and improvements within sensitive lands areas, as described in Exhibit N. 11-6.2. Hillside Area Classifications: Land in a Hillside Area must be evaluated according to the following slope categories. Each slope category indicates the relative suitability of land for development. 11-6.2.1. Zero percent (0%) to twenty percent (20%); flat to gently rolling land: Development with grading is permitted in this category. Land in this slope category is subject to the requirements of the excavation and grading permit requirements of the applicable building code. Open space requirements coincide with underlying zone. 11-6.2.3. Greater than twenty percent (>20%) to thirty percent (30%); hillside: Hillside Standards described in Section 11-6.3 apply. Required open space includes a minimum of 70% of the total land area. 11-6.2.4. Greater than thirty percent (>30%); steep hillside: This category is a sensitive slope condition, and development is limited. Hillside Standards described in Section 11-6.3 apply. Required open space includes a minimum of 90% of the total land area. TABLE 11.1 SLOPE AND REQUIRED OPEN SPACE Slope Category Percent Natural Slope 0% – 20% >20% – 30% >30% All Zones Required Open Space Underlying zoning applies 70 percent 90 percent 11-6.3. Hillside Area Development Standards: the following development standards govern development in Hillside Areas, as defined in this Chapter. 11-6.3.1. Architectural Standards: 11-6.3.1.1. Building Orientation and Setbacks: The land use applicant must provide a variety of building and lot orientations. Unless a greater setback is recommended in the geotechnical report or the structure is located on a prominent ridgeline where a greater 11-5 Adopted January 22, 2008; Revised November 11, 2014; Re-Formatted June 22, 2018 setback applies as detailed in this Chapter, a minimum building setback of fifteen feet from the top of a slope or an average setback of fifteen feet must be provided from the edge of the pad. 11-6.3.1.2. Viewshed Protection: 11-6.3.1.2.1. A structure must be designed so the slope angle of the roof pitch is generally at or below the angle of the natural hillside or graded slope. 11-6.3.1.2.2. A site plan must be designed to preserve views of prominent visual features such as ridgelines, as viewed from within and outside the hillside development. A building must be oriented to allow view opportunities and be located on the least sensitive portions of the site so as to preserve landforms, vegetation, and topographical features. 11-6.3.1.2.3. A hillside building must be stepped to follow the contours of the slope. Exterior structural supports and undersides of floors and decks not enclosed by walls are discouraged but may be permitted with fire safety and architectural considerations adequately addressed to the satisfaction of the city. 11-6 Adopted January 22, 2008; Revised November 11, 2014; Re-Formatted June 22, 2018 11-6.3.1.3. Building Style: The architectural style of a building must be compatible with the environment, character, topography, and theme of the community. Hillside adaptive architecture, as described below, must be used within the Hillside Area: 11-6.3.1.3.1. A building must be stepped as necessary to minimize grading. 11-6.3.1.3.2. A building design must include a variety of roof orientations and types that reflect the overall slope of the hillside. 11-6.3.1.3.3. Enhanced architectural elevations are required where any side of a structure is publicly visible. 11-6.3.1.3.4. Building dimensions as measured in the direction of the slope must be minimized to limit the amount of cut and fill and to better incorporate the structure into the natural terrain. 11-7 11-6.3.1.3.5. Buildings must be clustered to respect and adapt to the existing topography. The position of a structure and the size of lots must be adjusted as necessary to preserve the character of the hillside setting. 11-6.3.1.4. Architectural Treatments: A publicly visible exterior wall of a building must be designed to avoid monotonous or continuous facades. A single, continuous, vertical, or horizontal plane on the front and rear facade of any building is not permitted. Architectural features and details must be incorporated in all exterior walls of the publicly visible building, including the rear and sides of the building. Buildings may utilize wall articulation (i.e., insets, pop outs, etc.) and roof orientation as a means to break up the massing. 11-6.3.1.4.1. The form, mass, and profile of the individual buildings and architectural features must be designed to blend with the natural terrain and to preserve the character of the natural slope. The use of large gable ends on downhill elevations is prohibited. The predominant roof slope must be oriented in the same general direction as the natural slope. 11-6.3.1.4.2. prohibited. Large roof overhangs and cantilevers on downhill elevations are 11-8 11-9 11-6.3.2. Hillside Landscape Design Standards: 11-6.3.2.1. Landscaping must be designed to stabilize graded slopes and prevent erosion. The design must be compatible with surrounding natural vegetation. 11-6.3.2.1.1. Cut or Fill Slopes: All plant material used on cut or fill slopes must be compatible with plant material found on adjacent undisturbed hillsides. Design for cut or fill slopes must use Xeriscaping landscape methods. No irrigation system is allowed on or adjacent to the slope itself. 11-6.3.2.1.2. Pad Sites or Flat Areas: All plant materials on pad sites and areas with slopes of less than ten percent (10%) must be of a desert type requiring little or no irrigation. Hand-watered, fired pots or other similar watertight containers may be used to hold additional landscape materials. Any lawn area must be artificial grass. Any proposed landscaping other than rocks and colored or natural stones must consist of low-water plantings with minimal irrigation requirements. 11-6.3.2.1.3. Terraced Areas: On terraced areas between retaining walls, minimal desert type landscaping may be used as long as it complies with the regulations governing pad sites in Section 11-6.3.2.1.2. 11-6.3.2.1.4. Slope and Landscape Maintenance: Homeowners' associations (HOAs) and property owners’ associations (POAs) must maintain the slopes and landscaping of common open space in the Hillside Areas. If an affected owners’ association disbands or neglects its duties to maintain the slopes and landscaping, the city may contract with a landscape maintenance contractor for ongoing maintenance and place a lien against any and all private or common areas in the project to ensure repayment to the city of any incurred expense. 11-6.3.2.2. Before issuing an occupancy permit may be issued, the city must determine that the proposed site plan and landscaping plans comply with this Chapter and any conditions imposed during the hillside development process. 11-10 11-6.3.3. Retaining Walls: These regulations establish minimum development standards for retaining walls. The grading and concept plans must show the location, height, and type of any retaining wall, privacy wall, and fence. A retaining wall, privacy wall, and fence must be located within the disturbance limit for each lot or parcel. 11-6.3.3.1. General Standards: 11-6.3.3.1.1. The maximum length of any continuous retaining wall is 200 feet. 11-6.3.3.1.2. A retaining wall must be used to contain fill material or minimize cut or fill slopes. The retaining wall may extend only six inches above the material it is retaining. 11-6.3.3.1.3. A retaining wall must not block or restrict vehicular access to a dedicated or implied dedicated alley, access way, pedestrian access, trail, sidewalk, easement, or right of way. 11-6.3.3.1.6. Each retaining wall, freestanding wall, and fence must conform to the building codes of the city. 11-6.3.3.2. Height Standards: 11-6.3.3.2.1. No portion of a retaining wall may be more than ten feet tall, as measured from the immediately adjacent lowest natural or finished grade to the top of the wall. Retaining walls must not be stacked or terraced in any manner that increases their combined height beyond ten feet. Two sub-walls may be stacked or terraced to a maximum combined height of ten feet. A minimum separation of six feet is required between sub-walls as measured from the faces of the walls. The separation area between the sets of sub-walls must have low-water-use shrubs, low-maintenance shrubs, or other vegetation as approved in the landscape plan. No tree may be planted in the separation area between sub-walls unless the separation area between sub-walls is at least twenty linear feet. 11-11 11-6.3.3.2.2. For purposes of Section 11-6.3.3, retaining walls are not considered stacked or terraced if there is at least ten feet between the retaining walls. A retaining wall that is at least ten feet from another retaining wall may be constructed to the maximum allowable height as stated in Section 11-6.3.3.2.1. The separation area between the sets of retaining walls must have low-water use shrubs, low-maintenance shrubs, or other vegetation as approved in the landscape plan. No more than three adjacent retaining walls are allowed, and the maximum combined height of the adjacent retaining walls is 27 feet. 11-6.3.3.2.3. Retaining walls may be constructed to varying heights throughout a development. 11-6.3.3.2.3.1. A retaining wall in the side yard area may not be more than four feet tall; provided that such wall does not extend into a required front yard setback adjacent to a street. 11-6.3.3.2.3.2. A retaining wall in the rear yard area of a lot may not be more than eight feet tall. 11-6.3.3.2.3.3. Where a retaining wall contains fill above the natural grade and is located within a required setback yard, the height of the retaining wall is considered as contributing to the permissible height of a fence or wall at that location. A nonview-obscuring fence up to three and one-half feet (3.5') in height may be erected at the top of the retaining wall for safety. 11-12 Adopted January 22, 2008; Revised November 11, 2014; Re-Formatted June 22, 2018 11-6.3.3.2.4. A retaining wall may be used to provide a private outdoor area adjacent to a structure, but this retaining wall must not be more than six feet tall. 11-6.3.5. Grading Design: Grading for all developments must be designed to blend with the contours of the adjacent natural terrain. 11-6.3.5.1. Limits of Grading: Any grading, cutting, filling, excavating, benching, and terracing must not exceed the disturbance limitation imposed under the authority of this Chapter. 11-6.3.5.2. Cuts and Fills: All cuts and fills must be minimized and must be included within the disturbance limit for each lot or parcel. All cut and fill areas must be re-contoured to the natural, varied contours of the surrounding terrain with a maximum slope transition back to the natural grade no greater than two to one (2:1). Slope ratios greater than two to one (2:1) are prohibited except for approved cuts into solid rock only. For approved cuts into solid rock, the slope may be as steep as one-half to one (1/2:1) if recommended by a Utah-licensed professional engineer who is trained and experienced in the practice of geotechnical engineering, and if the visual impact of the cut can be adequately mitigated. Any area of cut and fill must be protected from erosion during construction and must be permanently planted or otherwise protected from erosion within 20 days of the completion of grading and excavation as identified by the approved landscape plan. Where cut or fill conditions are created, slopes must be varied and rounded where feasible rather than left at a constant angle. 11-6.3.5.3. Cuts and Fills Visual Mitigation: The visual impact of cuts and fills must be mitigated by methods approved by the city council. Mitigation efforts must be predominantly contour grading along with plantings as identified on the approved landscape plan that will stabilize the cut or fill slope and blend with the surrounding vegetation. Other mitigation 11-13 Adopted January 22, 2008; Revised November 11, 2014; Re-Formatted June 22, 2018 efforts may include, but are not limited to, positioning buildings to screen the cuts and constructing retaining walls designed to blend with the surrounding terrain. The use of retaining walls is to be as described in Section 11-6.3.3. Contour grading techniques must be used to provide a natural-appearing variety of slope transitions, slope percentage, and slope direction in a three-dimensional, undulating pattern similar to existing terrain. 11-6.3.5.3.1. Cut and fill operations must be given a rounded appearance that closely resembles the natural contours of the land. 11-6.3.5.3.1. Graded slopes adjacent to roadways must be softened by sufficient berms, contour grading, or landscaping to create natural, varied, and pleasing streetscapes. 11-6.3.5.4. Street and Driveway Alignment: A street must run generally parallel to the contours of the natural terrain. Short sections of streets that run perpendicular to natural contours and serve the purpose of connecting main parallel sections of streets are permitted and must follow the natural curves of drainage ways where practicable. Contour grading techniques must be used on all streets and associated cut and fill areas to minimize any adverse impacts. Reduced-width road sections, split-road sections, and split-parking bays 11-14 Adopted January 22, 2008; Revised November 11, 2014; Re-Formatted June 22, 2018 are potentially acceptable techniques to use in the layout of hillside streets to reduce grading. Any portion of a driveway that runs perpendicular to natural contours and serves the purpose of accessing building lots and parcels must be as short as practicable, as determined by the Development Committee. A driveway that serves more than one parcel is permitted as a method of reducing unnecessary grading, paving, and site disturbance. If a driveway is to be shared by lots or parcels, cross-use easements must be recorded with the subdivision. Shared driveways can reduce grading. 11-6.3.5.6. Building Site Grading: A property owner must minimize building site grading to preserve natural features. The building site plan must position each structure so that the necessary grading would not modify the general orientation of the slope. 11-15 11-6.3.5.7. Cut and Fill Conditions: A site plan must minimize cut and fill conditions consistent with this Chapter. Different terrain conditions call for corresponding different cut and fill solutions so that the structure fits well into the topography as illustrated below. Impact to natural drainage ways must be avoided. 11-16 11-17 11-6.4. Prominent Ridge and Mesa Edge Visual Preservation: To minimize the adverse visual impacts that new development can have on prominent ridges and their associated viewsheds, the following setbacks apply: 11-6.4.1. The setback from a ridgeline, as described in Exhibit N is 50 feet for one-story structures and sight-obscuring privacy fences and walls. Notwithstanding, if a greater setback is recommended in the geology report submitted under Section 11-5.9, then that setback is mandatory. 11-6.4.2. The setback from a ridgeline is 100 feet for 11/2- and two-story structures. Notwithstanding, if a greater setback is recommended in the geology report submitted under Section 11-5.9, then that setback is mandatory. 11-6.4.3. A greater setback may be recommended in the geology report or by the City Engineer or Development Committee for safety and stability. 11.6.5. Floodplain Areas: Developments proposed to occur in floodplain areas are subject to the Kanab Flood Damage Prevention Ordinance. 11-6.6. Corrective Work: Nothing in this Chapter prohibits the city from authorizing grading that is necessary to correct previously disturbed natural areas or existing hazardous conditions that are on site but not a part of the proposed development area that are brought to the city's attention. In that case, the applicant must investigate alternatives with subsequent review by the Development Committee, City Engineer, Planning Commission, or City Council.