All proposed development and improvements subject to the provisions of this chapter are subject to the following required development standards. These standards are intended to provide a framework for development that is sensitive to the unique characteristics of hillside properties. Their purpose is not to discourage proposals for innovative or alternative methods of design in a hillside area; innovation is encouraged as long as the end result is one which respects significant landform features and is consistent with the purposes expressed in this chapter and in the goals and objectives of the LaVerkin City general plan (chapters 2 and 3).
A. Disturbance Limitations: The following criteria shall be applied in establishing the limits of disturbance for a site:
1. Adverse visual impacts shall be minimized as much as possible. The screening of cuts and fills, and the visual protection of prominent ridgelines, rock outcroppings, scenic views, and as much of the natural terrain as practicable is required.
2. Disturbed slopes shall be treated to minimize erosion, and natural drainageways shall be protected as much as possible.
3. The clearing of trees, shrubs and other native vegetation shall be limited to: the approved locations for streets, driveways and easements; the approved locations for building pads for structures, main buildings and accessory structures; and the minimum distance between structures and surrounding vegetation for established fire prevention and safety standards or recommendations.
4. Significant trees, shrubs and other native vegetation shall be preserved in the design of the development. Significant vegetation is to be identified on a map with the application submittals and city staff will review the submittals and visit the site to determine the significance of existing vegetation.
5. The limits of disturbance may have borders or edges as long as the significant features of the natural terrain are being preserved.
6. All topsoil from any disturbed portion of the site shall be preserved and utilized in revegetation areas. The soil in the upper portion of fill areas shall be of a sufficient quality to support native plant growth.
7. The maximum limits of disturbance shall be identified on each lot or parcel of the approved site plans and subdivision plats and shall include all graded, excavated, and filled areas, the areas occupied by main and accessory structures, hard surface areas that include driveways, walkways, patios and parking areas, and all other areas of disturbance or nonnative vegetation.
B. Grading Design: Grading for all developments shall be designed to blend with the contours of the adjacent natural terrain.
1. Limits Of Grading: No grading, cutting, filling, excavating, benching or terracing of any proposed lot or parcel shall go beyond the maximum limits of disturbance for each lot or parcel as provided herein.
2. Cuts And Fills: All cuts and fills shall be minimized as much as practicable and shall be included within the maximum limits of disturbance for each lot or parcel. All cut and fill areas shall be recontoured 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. Any such proposed cut into rock shall be reviewed by planning commission with recommendation to city council for appropriateness, suitability, and visual impact in order to grant approval if warranted. 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. All areas of cut and fill shall be protected from erosion during the period of construction and shall be permanently planted or otherwise protected from erosion within twenty (20) days of the completion of grading and excavation as identified by the approved landscape plan.
Where cut or fill conditions are created, slopes shall be varied where feasible rather than left at a constant angle which may be unstable or create an unnatural, rigid, engineered appearance. (See section 10-7A-6, figure 1 of this chapter.)
3. Cuts And Fills Visual Mitigation: The visual impact of cuts and fills shall be mitigated by methods approved by the city engineer. This mitigation may include, but is not limited to, the placement of buildings in front of the cuts and/or the placement of retaining walls designed to blend with the surrounding terrain to stabilize the cut. Mitigation shall predominantly be 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. The use of retaining walls is to be as limited in scope and height as feasible to ensure the visual predominance of vegetation. Contour grading techniques shall 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, adjacent terrain.
a. Hard edges left by cut and fill operations shall be given a rounded appearance that closely resembles the natural contours of the land. (See section 10-7A-6, figure 2 of this chapter.)
b. Manmade slopes adjacent to roadways shall be softened where feasible by sufficient berms, contour grading, and/or landscaping to create visually interesting and pleasing streetscapes. (See section 10-7A-6, figure 3 of this chapter.)
4. Street And Driveway Alignment: Street alignments shall run generally parallel along the contours of the natural terrain as much as practicable. Short sections of streets that run perpendicular to natural contours and serve the purpose of connecting main parallel sections of streets are permitted and shall follow the natural curves of drainageways where practicable. Streets shall not greatly alter the physical and visual character of a hillside by creating large notches in ridgelines or by defining wide straight alignments. Contour grading techniques shall be employed on all streets and associated cut and fill areas to minimize any adverse impacts. The portions of driveways that run perpendicular to natural contours and serve the purpose of accessing building lots and parcels shall be as short as practicable. (See section 10-7A-6, figure 4 of this chapter.)
5. Open Space Trails: Where permitted, trails through open space shall be located such that cuts and fills are minimized and visual character is preserved. Where cuts and fills are required, cut conditions uphill from the trail typically have less of an overall visual impact than an exposed downhill fill area.
6. Structure Location: Design of building sites shall be sensitive to the natural terrain. Structures shall be located in such a way as to minimize grading and to preserve natural features. Careful consideration shall be given to the general orientation of the slope when locating structures. (See section 10-7A-6, figure 5 of this chapter.)
7. Building Sites: On each building site, careful consideration shall be given to the cut and fill conditions such that a balance is achieved where feasible and consistent with the intent of this chapter to minimize the visual impact of grading. Different slope conditions call for corresponding typical cut and fill solutions such that the structure fits well into the topography as illustrated below. Impacts to natural drainageways shall be avoided where possible. (See section 10-7A-6, figures 6 and 6A of this chapter.)
C. Viewshed Protection: To minimize the adverse visual impacts that development may potentially have on prominent ridgelines, mesas, and other site features, the following setbacks shall apply: Reserved.
D. Architectural Standards: The purpose of establishing architectural design standards in improvements and developments subject to this chapter is to ensure quality development that blends with the hillside environment and to create neighborhoods that display harmonious and complementary architectural styles. To achieve hillside compatible development, the city recognizes the importance of having architectural design that incorporates rooflines and other building elements that reflect the naturally occurring ridgeline silhouettes and topographical variations.
1. Building Orientation: A variety of building and lot orientations shall be provided in order to encourage development suitable with the hillside character of the site.
a. Structures shall be designed so the slope angle of the roof pitch is generally less than or equal to the angle of the natural hillside or manmade slope. (See section 10-7A-6, figure 8 of this chapter.)
b. Site planning shall emphasize the preservation of views to prominent visual features such as ridgelines. This includes building orientation to allow view opportunities and lot development on the least sensitive portions of the site to preserve landforms, vegetation and topographical features.
c. Hillside adaptive architecture shall be terraced 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 individual or body designated to grant approval.
2. Building Style: The use of hillside adaptive architecture as needed shall be incorporated into the design of individual lots. Step building foundations may be required to minimize grading. (See section 10-7A-6, figures 9, 10, and 11 of this chapter.)
a. Architectural styles shall be compatible with the hillside character, topography, and look of the community.
b. The dimensions of a building, measured in the direction of the slope, shall be minimized in order to limit the amount of cut and fill and to better incorporate the structure to the natural terrain.
3. Fencing And Privacy Walls: All fences and privacy walls adjacent to or clearly visible from public roads or parks shall be constructed of decorative masonry or other approved materials which have a natural appearance and shall be a color that blends with the surrounding environment and is complementary to the landscape. The applicant shall present illustrations and descriptions of fencing and wall materials as required by this section.
All walls and fences which are adjacent to or visible from public roads shall be set back from the right of way a minimum of ten feet (10') and landscaped on the street side of the wall or fence. A minimum flat area from top or toe of slope of three feet (3') or more as required by the adopted building codes of the city shall be maintained to face of wall on common area maintenance slopes with slope heights of thirty feet (30') or greater. (See section 10-7A-6, figure 12 of this chapter.)
E. Landscape Design Standards: Landscape materials and stabilization of graded slopes shall be designed to be compatible with surrounding natural vegetation. Plant material shall be selected according to compatible climatic, soil and ecological characteristics of the region.
F. Retaining Walls: The purpose and intent of establishing development standards for retaining walls is to ensure that the application of retaining walls are aesthetically pleasing elements within the subject property and limited in quantity throughout a development. The location of all retaining walls, privacy walls and fences shall be identified along with their proposed heights, materials and colors, and shown on the grading plan and concept plan. All retaining walls, privacy walls and fences shall be located within the maximum limits of disturbance for each lot or parcel.
1. General Standards:
a. Retaining walls shall be used for the purpose of containing fill material or for minimizing cut or fill slopes. The retaining wall may only extend six inches (6") above the material it is retaining.
b. A retaining wall shall not be constructed in such a manner so as to block or restrict vehicular access to a dedicated or implied dedicated alley, accessway, pedestrian access, trail, sidewalk, easement, or right of way.
c. All retaining walls and all privacy walls and fences surrounding a development's perimeter shall be faced with stone or earth colored materials complementary to the surrounding natural landscape.
d. Retaining walls shall follow the natural contours of the slope where feasible. Curved walls that follow the natural contours are recommended but not required.
e. All retaining walls as well as all freestanding walls and fences shall comply with the adopted building codes of the city.
2. Height Standards:
a. No retaining wall for a cut or fill area shall exceed ten feet (10') in height as measured from the immediately adjacent lowest natural or finished grade to the top of wall unless it can be demonstrated in the overall mitigation plan for cuts and fills that taller walls will not detract from the surrounding terrain and there is a predominance of vegetation in the fill areas. Retaining walls shall not be stacked or terraced in any manner that increases their combined height beyond ten feet (10'). If desired, two (2) subwalls may be stacked or terraced to a maximum combined height of ten feet (10'). A minimum separation of six feet (6') is required between subwalls as measured from face of wall. (See section 10-7A-6, figure 13 of this chapter.)
b. For purposes of this subsection, retaining walls are not considered stacked or terraced if there is a minimum horizontal separation of ten feet (10') between sets of retaining walls. With the minimum ten foot (10') separation, each retaining wall set may be constructed to the maximum allowed height; either the ten foot (10') height or the taller height demonstrated that would not detract from the surrounding terrain. The separation area between the sets of retaining walls shall be planted with low water use/low maintenance shrubs or other vegetation as approved in the landscape plan. Trees are not to be planted in the zone between terraced walls unless the distance between walls is a minimum of twenty feet (20'). This vegetation will help reduce the apparent visual height of the wall or walls.
c. Retaining walls may be constructed to varying heights throughout a development.
(1) Retaining walls constructed in the side yard area of a lot shall maintain a maximum retaining wall height of four feet (4'); provided that such wall does not extend into a required front yard adjacent to a street.
(2) Retaining walls constructed in the rear yard area of a lot shall maintain a maximum retaining wall height of eight feet (8').
(3) All planting areas between and adjacent to retaining walls shall be provided with an automatic irrigation system suitable for low water use vegetation. Such irrigation system shall be approved and inspected prior to the construction of any wall.
(4) Where a retaining wall contains fill above the natural grade and is located within a required setback yard, the height of the retaining wall shall be considered as contributing to the permissible height of a fence or wall at that location. A non- view 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.
d. Retaining walls not exceeding six feet (6') in height are permitted adjacent to structures in order to provide a private outdoor area.
e. To the extent that there is an inconsistency or discrepancy between a requirement and/or provision of subsection 10-7-7F of this title and this chapter, the stricter requirement/provision shall apply.
G. Corrective Work: Nothing in this section shall prohibit the individual or body designated to grant approval from authorizing grading deemed necessary to correct previously disturbed natural areas or existing hazardous conditions that are on site but not a part of the proposed development area and that are brought to the city's attention. In such case, the applicant will investigate possible alternatives with subsequent review by the individual or body designated to grant approval. (Ord. 2013-03, 4-3-2013)