(A) Purpose: The purpose of this section is to identify various types of developments that normally pose special concerns to the commission and elected officials when reviewing and acting upon subdivision requests. This section outlines the plan submittal requirements and design standards that shall be taken into consideration when acting on special developments. The provisions of this section are in addition to the plan requirements, design standards and improvement standards that are required by sections
3-2-3,
3-2-4 and
3-2-5 of this chapter.
(B) Hillside Subdivision:
1. Appearance And Preservation: In order to preserve, retain, enhance and promote the existing and future appearance, natural topographic features, qualities and resources of hillsides, special consideration shall be given to the following:
(a) Skyline and ridge tops;
(b) Rolling grassy landforms, including knolls, ridges and meadows;
(c) Trees and shrub masses, grass, wildflowers and topsoil;
(e) Streambeds, draws and drainage swales, especially where tree and plant formations occur; and
(f) Characteristic vistas and scenic panoramas.
2. Hillside Development Evaluation:
(a) All development proposals shall take into account, including, but not limited to:
(1) Planning of development to fit the topography soils, geology, hydrology and other conditions existing on the proposed site;
(2) Orientation of development on the site so that grading and other site preparation is kept to an absolute minimum;
(3) Shaping of essential grading to blend with natural landforms and to minimize the necessity of padding and/or terracing of building sites;
(4) Division of large tracts into smaller workable units on which construction can be completed within one construction season so that large areas are not left bare and exposed during the winter-spring runoff period; (Ord. 397, 1983)
(5) Completion of paving as rapidly as possible after grading; (Ord. 620, 3-8-2010)
(6) Allocation of areas not well suited for development because of soil, geology or hydrology limitations for open space and recreation uses;
(7) Minimizing disruption of existing plant and animal life; and
(8) Consideration of the view from and of the hills.
(b) Areas having soil, geology or hydrology hazards shall not be developed unless it is shown that:
(1) Hazard to life or property will not exist;
(2) The safety, use or stability of a public way or drainage channel is not jeopardized; and
(3) The natural environment is not subjected to undue impact.
3. Engineering Plans: The developer shall retain a professional engineer(s) to obtain the following information:
(a) Soils Report: For any proposed hillside development a soils engineering report shall be submitted with the preliminary plat.
(1) For any proposed hillside development a geology report shall be submitted with the preliminary plat.
(2) The investigation and subsequent report shall be completed by a professional geologist registered in the state.
(1) For any proposed hillside development a hydrology report shall be submitted with the preliminary plat.
(2) Flood frequency curves shall be provided for the area proposed for development.
(a) A preliminary grading plan shall be submitted with each hillside preliminary plat proposal and shall include the following information:
(1) Approximate limiting dimensions, elevations or finish contours to be achieved by the grading, including all cut and fill slopes, proposed drainage channels and related construction;
(2) Preliminary plans and approximate locations of all surface and subsurface drainage devices, walls, dams, sediment basins, storage reservoirs and other protective devices to be constructed; and
(3) A description of methods to be employed in disposing of soil and other material that is removed from the grading site, including the location of the disposal site.
(b) A final grading plan shall be submitted with each final plat and shall include the following information:
(1) Limiting dimensions, elevations or finish contours to be achieved by the grading, including all proposed cut and fill slopes, and proposed drainage channels and related construction;
(2) Detailed plans and locations of all surface and subsurface drainage devices, walls, dams, sediment basins, storage reservoirs and other protective devices to be constructed; and
(3) A schedule showing when each stage of the project will be completed, including the total area of soil surface which is to be disturbed during each stage together with estimated starting and completion dates. In no event shall the existing natural vegetative ground cover be destroyed, removed or disturbed more than fifteen (15) days prior to grading.
5. Development Standards:
(1) Fill areas shall be prepared by removing organic material, such as vegetation and rubbish, and any other material which is determined by the soils engineer to be detrimental to proper compaction or otherwise not conducive to stability; no rocks or similar irreducible material with a maximum dimension greater than eight inches (8") shall be used as fill material in fills that are intended to provide structural strength.
(2) Fills shall be compacted at least ninety five percent (95%) of maximum density, as determined by AASHO T99 and ASTM D698.
(3) Cut slopes shall be no steeper than two horizontal to one vertical (2:1); subsurface drainage shall be provided as necessary for stability.
(4) Fill slopes shall be no steeper than two horizontal to one vertical (2:1); fill slopes shall not be located on natural slopes two to one (2:1) or steeper, or where fill slope toes out within twelve feet (12') horizontally of the top of an existing or planned cut slope.
(5) Tops and toes of cut and fill slopes shall be set back from property boundaries a distance of three feet (3') plus one-fifth (1/5) of the height of the cut or fill but need not exceed a horizontal distance of ten feet (10'); tops and toes of cut and fill slopes shall be set back from structures a distance of six feet (6') plus one-fifth (1/5) the height of the cut or fill, but need not exceed ten feet (10').
(6) The maximum horizontal distance of disturbed soil surface shall not exceed seventy five feet (75').
(1) Road alignments should follow natural terrain and no unnecessary cuts or fills shall be allowed in order to create additional lots or building sites.
(2) One-way streets shall be permitted and encouraged where appropriate for the terrain and where public safety would not be jeopardized. Maximum width shall be seventeen feet (17') between backs and curbs.
(3) The width of the graded section shall extend three feet (3') beyond the curb back or edge of the pavement on both the cut and fill sides of the roadway. If sidewalk is to be installed parallel to the roadway, the graded section shall be increased by the width of the sidewalk plus one foot (1') beyond the curb back. (Ord. 397, 1983)
(4) Standard rolled curb and gutters will be installed along both sides of all paved roadways. (Ord. 620, 3-8-2010)
(5) A pedestrian walkway plan shall be required.
(c) Driveways And Parking:
(1) Combinations of collective private driveways, cluster parking areas and on street parallel parking bays shall be used to attempt to optimize the objectives of minimum soil disturbance, minimum impervious cover, excellence of design and aesthetic sensitivity.
6. Vegetation And Revegetation:
(a) The developer shall submit a slope stabilization and revegetation plan which shall include a complete description of the existing vegetation, the vegetation to be removed and the method of disposal, the vegetation to be planted, and slope stabilization measures to be installed. The plan shall include an analysis of the environmental effects of such operations, including the effects on slope stability, soil erosion, water quality and fish and wildlife.
(b) Vegetation sufficient to stabilize the soil shall be established on all disturbed areas as each stage of grading is completed. Areas not contained within lot boundaries shall be protected with perennial vegetal cover after all construction is completed. Efforts shall be made to plant those species that tend to recover from fire damage and do not contribute to a rapid rate of fire spread.
(c) The developer shall be fully responsible for any destruction of native vegetation proposed for retention. He shall carry the responsibility both for his own employees and for all subcontractors from the first day of construction until the notice of completion is filed. The developer shall be responsible for replacing such destroyed vegetation.
7. Maintenance: The owner of any private property on which grading or other work has been performed pursuant to the grading plan approved or a building permit granted under the provisions of this chapter shall continuously maintain and repair all graded surfaces and erosion prevention devices, retaining walls, drainage structures or means, and other protective devices, plantings and ground cover installed or completed.
8. New Service Utilities: All new service utilities shall be placed underground.
(C) Planned Unit And Condominium Subdivisions:
1. General: Planned unit and condominium developments shall be subject to requirements set forth in the zoning ordinance and also subject to all provisions within this chapter.
2. Minimum Area: A planned unit development for the following principal uses shall contain an area of not less than:
(a) Three (3) acres or one city block for residential use, except for a mobile home subdivision;
(b) Five (5) acres for mobile home subdivisions;
(c) Five (5) acres for residential use with subordinate commercial use;
(d) Ten (10) acres for commercial use; and
(e) Ten (10) acres for industrial use.
3. Site Development Plan: The developer shall provide the commission with a colored rendering of adequate scale to show the completed development that will include at least the following:
(a) Architectural style and building design;
(b) Building materials and color;
4. Private Streets: Private street construction standards shall be based upon recommendations from the City Engineer. Adequate construction standards may vary depending on the size of the development and the demands placed on such improvements.
5. Home Owner's Association: The home owner's association by-laws and other similar deed restrictions, which provide for the control and maintenance of all common areas, recreation facilities or open space shall meet with the approval of the Council. Any and all powers as specified in such agreements may also be assigned to the Council for the purpose of assessing the property for delinquencies and enforcement of motor vehicle speed to protect the best interests of the owners involved and of the general public.
6. Storage Areas: Storage areas shall be provided for the anticipated needs of boats, campers and trailers. For typical residential development, one adequate space shall be provided every one living unit. This may be reduced by the Council if there is showing that the needs of a particular development are less.
7. Parking Space: One additional parking space beyond that which is required by the Zoning Ordinance may be required for every three (3) dwelling units to accommodate visitor parking.
8. Maintenance Building: A maintenance building shall be provided, size and location to be suitable for the service needs that are necessary for the repair and maintenance of all common areas.
9. Open Space: The location of open space shall be appropriate to the development and shall be of such shape and area to be usable and convenient to the residents of the development.
10. Control During Development: Single ownership or control during development shall be required and a time limit may be imposed to guarantee the development is built and constructed as planned.
(D) Mobile Home Subdivision:
1. General: Mobile home subdivisions shall be subject to any requirements set forth in the Zoning Ordinance.
2. Special Requirements: Mobile home subdivisions shall be subject to the following special requirements:
(a) Developed as planned unit development with a minimum of area for the planned development of five (5) acres;
(b) Screening from adjacent areas, other than subdivisions of the same type, by aesthetically acceptable fences, walls, living planting areas and existing natural or manmade barriers; and
(c) Creation of a home owner's association to assure that all common areas are adequately maintained.
(E) Large-Scale Development Subdivision:
1. Required Information: Due to the impact that a large-scale development would have on public utilities and services, the developer shall submit the following information along with the preliminary plat:
(a) Identification of all public services that would be provided to the development (i.e., fire protection, police, central water, central sewer, road construction, parks and open space, recreation, maintenance, schools and solid waste collection);
(b) Estimate the public service costs to provide adequate service to the development;
(c) Estimate the tax revenue that will be generated from the development; and
(d) Suggested public means of financing the services for the development if the cost for the public services would not be offset by tax revenue received from the development.
(F) Cemetery Subdivision:
1. The developer shall provide the Commission with written documentation that will sufficiently explain the functions of the proposed cemetery for either human or animal remains; and
2. The developer shall submit a written statement that has been prepared by an attorney that adequately assures the compliance of the proposed cemetery with the procedural management requirements that are outlined in title 27, Idaho Code.
(G) Subdivision Within a Flood Plain:
(a) For any proposed subdivision that is located within a flood plain, the developer shall provide the Commission with a development plan of adequate scale and supporting documentation that will show and explain at least the following:
(1) Location of all planned improvements;
(2) Location of the floodway and the floodway fringe, per engineering practices as specified by the Army Corps of Engineers;
(3) The location of the present water channel;
(4) Any planned re-routing of waterways;
(5) All major drainage ways;
(6) Areas of frequent flooding;
(7) Means of flood proofing buildings; and
(8) Means of insuring loans for improvements within the flood plain.
2. Justification for Development:
(a) Upon the determination that buildings are planned within the flood plain or that alterations of any kind are anticipated within the flood plain that will alter the flow of water, the developer shall demonstrate conclusively to the Commission that such development:
(1) Will not present a hazard to life, limb or property; and
(2) Will not have adverse effects on the safety, use or stability of a public way or drainage channel or the natural environment.
(b) No subdivision or part thereof shall be approved if levees, fills structures or other features within the proposed subdivision will individually or collectively significantly increase flood flows, heights or damages. If only part of a subdivision can be safely developed, the Council shall limit development to that part and shall require that development proceed consistent with that determination.
(c) Subdivisions shall be reviewed to assure that:
(1) All such proposals are consistent with the need to minimize flood damage;
(2) All public utilities and facilities, such as sewer, electrical and water systems are located and constructed to minimize or eliminate flood damages; and
(3) Adequate drainage is provided so as to reduce exposure to flood hazards.
(d) New or replacement water supply systems and/or sanitary sewage systems shall be designated to minimize or eliminate infiltration of flood waters into the systems and discharges from the systems into flood waters, and require on-site wastes disposal systems to be located so as to avoid impairment of them or contamination from them during flooding.
(H) Subdivision Within an Area of Critical Concern:
1. General: Hazardous or unique areas may be designated as an area of critical concern by the Council or by the State. Special consideration shall be given to any proposed development within an area of critical concern to assure that the development is necessary and desirable and in the public interest in view of the existing unique conditions. Hazardous or unique areas that may be designated as areas of critical concern are as follows:
(b) Earthquake locations;
(g) Historical significance;
(i) Other areas of critical concern.
2. Plan Submission: The developer shall prepare and submit an environmental assessment along with the preliminary plat application for any development that is proposed within an area of critical concern.
3. Content of Environmental Assessment: The content of the environmental assessment shall usually be prepared by an interdisciplinary team of professionals that shall provide answers to the following questions:
(a) What changes will occur to the area of environmental concern as a result of the proposed development?
(b) What corrective action or alternative development plans could occur so as not to significantly change the area of environmental concern?
(c) What changes in the area of environmental concern are unavoidable? and
(d) What beneficial or detrimental affect would the development have on the environment (i.e., animal life, plant life, social concerns, economic noise, visual and other)?