No preliminary plat application shall be approved unless the Board makes a positive finding that the application complies with each of the following standards. No waiver of any of these standards may be granted except pursuant to section 10-8-5 of this title.
   A.   Preservation Of Natural Features: Where found practicable and appropriate, the following specific areas regardless of location shall be left undeveloped and undisturbed:
      1.   Unique or fragile areas such as geologic features and natural topography of the land with the goal of preserving the character, natural features and configuration of land terrain;
      2.   Areas of natural vegetation, including unique landscapes, large individual trees, and stands of trees, excluding irrigation rights-of-way under Idaho Code 42-1101. A plan for landscape protection, tree preservation, and tree introduction shall be evaluated to determine compliance with this standard;
      3.   Natural habitat and other areas of significant value to wildlife, including migration corridors as identified by Idaho Fish and Game;
      4.   Historically significant structures or sites; and
      5.   Wetlands, natural drainage channels or watercourses.
   B.   Lot Requirements:
      1.   Each lot shall contain a satisfactory building site which is properly related to topography.
      2.   Corner lots shall be a sufficient area without obstructive landscaping to provide acceptable visibility for traffic safety.
      3.   Each lot shall have access to an internal street or drive, where practicable.
      4.   Calculation of lot area shall not include land which is below the "natural or ordinary high water mark" of navigable streams (as defined by Idaho Code sections 50-1202 and 36-1601), and therefore subject to the public trust doctrine.
      5.   If lots in a residential land use area are more than double the minimum acreage required for a Residential Zoning District (R-.4 - R-21/2), equal or exceed the minimum acreage required in the Residential/Agricultural District (R-5) or are within an Area of City Impact, applicants may be required to arrange lots in anticipation of future resubdivision and provide for future streets where necessary to serve potential lots.
      6.   Each lot located adjacent to public lands shall have adequate setbacks and a landscaping plan which provide defensible space to protect private property from wildland fires, to reduce the likelihood of fires spreading from private property to public lands, and to protect public health, safety and welfare.
The Board may consider additional requirements recommended by the fire district, including, but not limited to, larger building setbacks from public lands, additional water supply systems, and specific landscaping design. The Board may also consider options proposed by the applicant to meet the safety goals of this subsection.
   C.   Blocks: Blocks shall be designed to assure traffic safety and ease of traffic control and circulation. Blocks shall allow for two (2) tiers of lots unless topography or other factors indicate irregularly shaped blocks indented by cul-de- sacs. The Board has the authority to review and modify block sizes.
   D.   Utilities: The subdivider shall:
      1.   Grant a public and private utility easement of at least ten feet (10') in width on the edge of the access road right-of- way and, where topographic or other conditions permit, centered on all side lot lines;
      2.   Install utilities prior to road surfacing; and
      3.   Where practicable, relocate underground any existing aboveground utilities, excluding power transmission lines.
   E.   Drainage:
      1.   The subdivider shall provide suitable drainage facilities for any surface runoff from within or upstream of the subdivision. Natural drainage channels shall be used whenever possible. To avoid soil erosion and manage nutrients, sediment catchment basins may be required.
      2.   Where a subdivision contains a stream, watercourse, drainageway, channel or ditch, an easement shall be provided adequate to contain that watercourse and any further width necessary for maintenance or reconstruction.
   F.   Water Supply:
      1.   Central Water Systems:
         a.   Circular or looped water supply systems may be required.
         b.   In addition to subsection F1a of this section and the requirements of subsection 10-5-1F2 of this chapter, the Board reserves the option to require central water systems for subdivisions where necessary to provide for the public health, safety or general welfare.
      2.   Irrigation System Requirements: All subdivisions shall satisfy the requirements of Idaho Code section 31-3805 for irrigation water delivery.
   G.   Sewage Disposal:
      1.   All sewage disposal systems shall meet any additional requirements that the Board deems necessary to protect the public health, safety or general welfare.
      2.   The Board may determine larger minimum lot sizes than one acre upon evaluation of engineering reports. The Board may require a second engineer's opinion where necessary (modifications to lot size when connected to a central sewer system may be granted through a CH-PUD).
   H.   Solid Waste Disposal: The subdivider shall present a written plan for:
      1.   The orderly and efficient removal of solid waste from the subdivision to the County Landfill or disposal site;
      2.   The grinding of recyclable yard waste; and
      3.   The recycling of other types of recyclable waste.
   I.   Park Or School Site Dedication: Based on a recommendation regarding the suitability of the site from the recreation or school district, an applicant may be required to provide either land or a financial contribution or both for playgrounds, recreation space or a school site based on a rationally related formula determined by a resolution or ordinance of the Board.
   J.   Access Easements: The Board may require an access easement to publicly administered land, streams, rivers, lakes and reservoirs. An applicant shall clearly delineate for the public the location of any access easement by appropriate signage and rail fencing, and create an obligation by the homeowners' association to maintain unrestricted passage by the public. The Board may require a bike path connector to the existing recreation district trail system or an easement for a future trail system connection.
   K.   Development Rights: On a final subdivision or PUD plat, the applicant may be required to relinquish, or transfer to an approved land trust, any residual rights to develop residential, commercial or industrial uses in all common or open space areas, as those are defined in this title.
   L.   Hillside Standards:
      1.   Areas Of Use: Hillside subdivision standards shall apply to: a) any portions of the development proposal within the Mountain Overlay District (see title 9, chapter 21 of this Code); and b) any portion of the development proposal outside the Mountain Overlay District where the slopes exceed fifteen percent (15%) and where the Board determines that it is in the best interest of the County that development be in accordance with these standards because of slope instability, erosion or sedimentation problems.
      2.   Additional Requirements: Additional preliminary submission requirements for hillside subdivisions:
         a.   A hydrogeological report and map depicting the depth to bedrock if less than ten feet (10'), areas of potential slope instability and areas where springs or runoff may increase soil erosion;
         b.   A slope stabilization and revegetation plan;
         c.   A grading plan containing existing and finish contours; and
         d.   A slope map and generalized soils description.
      3.   Appearance: In order to enhance the existing and future appearance and resources of hillside areas, special effort shall be made to preserve the following natural features:
         a.   Skyline, ridges and knolls.
         b.   Tree and shrub clusters.
         c.   Rock outcroppings.
         d.   Streambeds, draws and drainage swales.
      4.   Hillside Subdivision Evaluation: In addition to considerations pertinent to regular subdivisions, no structure or building envelope shall be located within the Mountain Overlay District. For a parcel of land that straddles the Mountain Overlay District and another district, individual lots may be drawn that include portions of the Mountain Overlay District. However, each lot shall include buildable land outside of the Mountain Overlay District. Also, the commission and Board shall consider:
         a.   The compatibility of the development with the topography, soils, geology, hydrology and other physical conditions at the proposed site.
         b.   The orientation of structure siting so that grading and site preparation can be kept to a minimum.
         c.   The phasing of the construction of large projects so that large areas are not left exposed to erosion for long periods of time.
         d.   The visibility of the proposed development. Visibility of structures, roads, streets or driveways shall be minimized through design and siting and shall have least visual impact as viewed from any reference road. Structures shall remain below the skyline and sited in such a manner so as not to create a silhouette against the sky as viewed from said reference roads.
         e.   The arrangement of the housing units to complement one another and the natural landscape.
         f.   Variations to standard circulation systems and parking where consistent with traffic safety to minimize cut and fill.
   M.   Design Of Subdivisions Within Or Adjacent To Lands Zoned A-20, A-40, R-10 Or RR-40: Subdivisions shall be designed to preserve natural, open space and scenic resources, protect sensitive areas such as riparian areas, wetlands, wildlife habitat and wildlife migration corridors, and watercourses, and reduce impact on neighboring properties.
      1.   In addition to the above, subdivisions within or adjacent to lands zoned A-20, A-40, R-10 and RR-40 shall be designed and residential structures located to minimize the impact on agricultural land, farming operations, and sensitive environmental features. The Board should consider, without limitation, the following design criteria:
         a.   Locating residential structures as far from neighboring agricultural lands as possible;
         b.   Grouping land uses as much as practical, such that agricultural lands abut neighboring agricultural lands and residential structures are located contiguous with other residential uses;
         c.   Locating structures on the least productive agricultural land and in such a manner as to have little impact on any environmental, agricultural or open space resources; and
         d.   Placing residential structures nearest to utilities and roads to minimize the amount of infrastructure and the loss of agricultural land.
         e.   A buffer between different types of uses (i.e., residential and agricultural) may be required.
      2.   For lands located within the R-2, R-21/2, and R-5 Zoning District subdivisions, nothing in this subsection is intended to substitute or limit the ability to submit a development proposal for a planned unit development pursuant to chapter 6 of this title. The Board shall consider, but is not limited to, the following design criteria:
         a.   Placing residential buildings nearest to utilities and roads to minimize the amount of infrastructure, except along State Highway 75 where a greater than one hundred foot (100') setback may be required.
         b.   Building envelopes (or nonbuilding areas, if more applicable), building size limits, increased lot line setbacks, and a buffer between neighboring properties may be required if they are deemed necessary in order to preserve and protect natural topographic and geologic features, scenic vistas, open space, vegetation, wildlife habitat and migration corridors, and avoid disturbance of sensitive areas; and to enable development patterns that minimize the potential impact of new development on adjacent landowners.
         c.   In order to accomplish the goals of this section and allow for a positive finding, the Board may allow the minimum lot sizes in the R-2, R-21/2 and R-5 Zoning Districts to be reduced by up to twenty percent (20%).
   N.   Street Improvements: Modifications acceptable to the applicable fire district and County Engineer may be granted through a CH-PUD.
      1.   Conformance To Plans: Streets shall in general conform with the comprehensive plan, other accepted plans, any section of the County's Right-of-Way Management Plan, and the provisions of this title.
      2.   Dedication: Collector and arterial streets within a proposed subdivision shall be offered for dedication to the public. Minor streets may be dedicated or kept private. Private roads will not be allowed where there is a need for public access to adjacent lands. Dedication or other provision for future access to surrounding areas may be required.
      3.   Conditions: The arrangement, type, extent, width, grade and location of all streets shall be considered in their relation to existing and planned streets, to topographical conditions, to public convenience and safety and in their relation to the proposed uses of the land to be served by such streets.
      4.   Location: Streets shall be located by the following guidelines:
         a.   Streets shall be arranged in proper relation to topography so as to result in usable lots, safe streets and acceptable gradients.
         b.   Where adjoining areas are not subdivided, the arrangement of streets in new subdivisions may allow streets to extend to the tract boundary to make provisions for the future extension of streets into adjacent areas. A temporary cul-de-sac may be made to serve present traffic.
         c.   Minor streets shall be arranged to discourage through traffic.
         d.   Dead end streets are prohibited. Stub streets with a temporary cul-de-sac may be permitted in anticipation of a future through street.
         e.   Cul-de-sac streets shall be discouraged. However, when topography or planning considerations dictate their use, cul- de-sacs shall:
            (1)   Include a right-of-way measuring one hundred feet (100') in diameter at the terminus;
            (2)   Include an additional snow storage easement of ten feet (10') around the periphery; and
            (3)   If offered for dedication to the County, meet County road specifications and include an entirely paved terminus measuring ninety feet (90') in diameter.
The Board shall have the explicit option of accepting or rejecting the road for dedication to the County.
         f.   Half streets shall normally be prohibited except where satisfactory assurance for dedication of the other half is provided.
         g.   Encourage streets to be laid out so that the lot design facilitates the use of solar energy.
   O.   Intersection Location And Specifications: Intersections shall conform to the following (modifications acceptable to the applicable fire district and County Engineer may be granted through a CH-PUD):
      1.   Intersections of minor streets with major arterials or highways shall be kept to a minimum.
      2.   Streets shall intersect at right angles or as close thereto as possible.
      3.   Intersection design shall provide acceptable visibility for traffic safety.
      4.   A nearly flat grade with appropriate drainage slopes is desirable within intersections. This flat section shall be extended a minimum of one hundred feet (100') each way from the intersection. An allowance of two percent (2%) maximum intersection grade in rolling terrain will be permitted.
      5.   The Board may require deceleration and left turn lanes at intersections.
   P.   Landscaping And Grading: The landscaping and grading plan shall minimize lot disturbance, maintain existing topography to the greatest extent possible, maintain or restore natural landscapes, shall emphasize drought tolerant species, where applicable, and shall include an irrigation plan that shows how disturbed areas will be restored.
   Q.   Nonmotorized Facilities: Applicants may be required to accommodate in the subdivision design nonmotorized transportation facilities, such as bike, equestrian and pedestrian paths, and facilities for public transportation services.
   R.   Wildlife: Lands in the Wildlife Overlay District shall be developed as permitted by title 9, chapter 20 of this Code. In addition, the following standards shall apply:
      1.   Fencing:
         a.   General: Both internal and perimeter fencing on sites containing wildlife habitat shall be kept to a minimum necessary to contain livestock and domestic animals and to provide privacy. No fencing is the strongly preferred option.
         b.   Perimeter Fences: Perimeter fencing of properties containing classified lands is prohibited except if necessary for containment of livestock as part of a bona fide agricultural operation. Such fencing shall be constructed according to the standards below.
         c.   Interior Fences: Interior fences may be constructed within each lot to control domestic pets and animals according to the standards below. Interior fencing shall be restricted to the smallest area practicable within the activity envelope.
         d.   Wire Fencing: Wire fencing for containment of livestock in or adjacent to critical wildlife habitat areas such as migration corridors shall have three (3) strands or less. The top wire should be a 12.5-gauge twisted barbless or similar type at a maximum height of forty two inches (42"). The middle strands, which may be barbed, should be located a minimum of twelve inches (12") from the top wire to prevent entanglement when animals jump over the fence. The bottom strand should be barbless and a minimum of eighteen inches (18") from the ground.
         e.   Rail Fencing: Rail fencing shall employ three (3) rails or less and shall not exceed forty six inches (46") in height above ground level, twelve inches (12") in width (top view), and the lower rail should be a minimum of eighteen inches (18") from the ground. Solid wood fencing should generally be limited to areas around a primary residence and shall be prohibited on classified lands.
      2.   Domestic Animals: Development applications in the Wildlife Overlay District shall include a plan with specific enforcement measures for the control of domestic animals and pets. Such plan must include provisions to prevent the harassment, disturbance, and killing of wildlife and prevent the destruction of critical wildlife habitat.
      3.   Outdoor Lighting: Use of exterior lighting shall be minimized near critical wildlife habitat. Lighting shall be designed to prevent spillover into habitat and all exterior lighting must be fully shielded by cutoffs with an angle not exceeding ninety degrees (90°). All outdoor lighting shall comply with title 9, chapter 29A of this Code.
      4.   Construction Timing: The County may regulate the timing of construction or land disturbance on classified lands as recommended by IDF&G, any other applicable agency or review professional who may be engaged by the County.
   S.   Gates: Limited entry or private gates may be prohibited at the entrance to any nonagricultural development approved under this title.
   T.   Riparian And Wetland Areas: Areas of riparian plant communities and wetlands shall be preserved and undisturbed to support a diverse and productive aquatic and terrestrial habitat and to protect water quality. The applicant may demonstrate that smaller setbacks are warranted than those defined in subsection 10-5-1B of this chapter through the completion and approval of a riparian area management and mitigation plan. In no case, will the setbacks be less than the setbacks defined in subsection 9-17-7D of this Code. In considering this standard, prior disturbances of the riparian plant community may be taken into account, and restoration of previously vegetated areas supporting riparian plant communities may be required. (Ord. 2019-09, 5-28-2019; Ord. 2010-06, 5-25-2010; Ord. 2009-05, 7-7-2009; Ord. 2006-19, 11-14-2006; Ord. 2006-18, 11-2-2006; Ord. 2006-16, 11-2-2006; Ord. 2006-15, 10-26-2006; Ord. 2006-08, 6-29-2006; Ord. 98-8, 10-5-1998)