§ 155.366 DESIGN STANDARDS.
   (A)   Natural conditions protected. All subdivisions shall comply with the following standards.
      (1)   The design and development of subdivisions shall preserve insofar as possible the natural terrain, natural drainage, existing topsoil and trees.
      (2)   Land subject to hazardous conditions such as slides, mud flows, rock falls, snow avalanches, possible mine subsidence, shallow water table, open quarries, floods and polluted or non-potable water supply shall be identified and shall not be subdivided until the hazards have been eliminated or will be eliminated by the subdivision and construction plans.
   (B)   Lots. All lots approved for building shall comply with the following.
      (1)   All lots shall conform in dimension and acreage requirements of the zone in which they are located.
      (2)   Lots shall meet the minimum requirements of this chapter and the Local Health Department for wastewater disposal.
      (3)   All lots shall abut a dedicated street, a public street, a street which has become public by right of use or a private street maintained by a maintenance agreement.
      (4)   The travel surface for streets shall be at least twenty-four feet wide. In the event a lot abuts a public right-of-way created by use, the subdividers shall improve the right-of-way to the standards required by this chapter.
      (5)   Corner lots shall have extra width sufficient for maintenance of required building lines and setbacks on both streets.
      (6)   All remnants of lots less than minimum size left over after subdividing a larger tract shall be added to adjacent lots rather than allowed to remain lot remnants.
      (7)   No single lot shall be divided by a municipal or county boundary line.
      (8)   A lot shall not be divided by a road, alley or other lot.
      (9)   No wedge-shaped lot shall be less than 30 feet in width at the front property line.
   (C)   Street standards. All county streets and roads shall be designed and built to the AASHTO standards. The designing engineer shall certify in writing that this is the case when the preliminary plats are submitted for approval.
      (1)   Stub streets with approved turn-arounds shall be provided where needed to connect to adjacent undeveloped land, and new streets shall be provided where needed to connect to existing stub streets in adjacent subdivisions. Not more than three lots shall front stub streets, except where a temporary cul-de-sac turnaround is provided.
      (2)   Intersections of minor streets with major streets shall be kept to the minimum possible.
      (3)   Streets shall have the following minimum right-of-way widths:
         (a)   Major Collector: 100 feet
         (b)   Minor Collector: 66 feet
         (c)   Collector Street: 66 feet
         (d)   Major Street: 66 feet
         (e)   Minor Streets and Frontage Roads: 66 feet
         (f)   Private Street or Road: Private streets or road rights-of-way are not under the authority of the county and shall not be restricted in any manner except that the county may require a minimum 66 feet road right-of-way for future public needs if it is apparent that more lots may developed in the future that will require a public road to service these lots.
      (4)   Maintenance of private streets is the responsibility of the land owner(s). If the street is to ever become a public street, it shall be brought up to county road standards prior to the county accepting maintenance responsibility.
      (5)   If the private property owners that the road serves request that the road become a public road, they shall pay the cost of doing so. If the county or some other public entity requests that the road become a public road, the costs of bringing the road to county standards may be negotiated.
      (6)   The county shall not take a private road right-of-way against a private property owner’s will for public use without due process and fair compensation.
      (7)   All county roadway travel surface widths shall be consistent with AASHTO Standards for the use and speed to be traveled on said roads as determined by the designing engineer and approved by the County Public Works Director.
      (8)   Minimum ten-foot shoulders shall be provided where there are no curbs installed.
      (9)   No half-streets are permitted, except if required to complete a half-street already existing and approved by the Planning Commission and the County Commission.
      (10)   Dead-end streets and or street stubs shall have approved temporary turn-arounds and/or shall be built to accommodate future access to adjoining properties.
      (11)   Approved permanent cul-de-sac streets shall serve no more than six lots and extend not more than 500 feet with the cul-de-sac having a minimum radius of 50 feet or more, and the outside curb or pavement edge radius as required by fire code.
      (12)   No more than four streets shall enter an intersection.
      (13)   Streets shall intersect at 90 degrees.
      (14)   Two streets meeting a street from opposite sides shall meet at the same point, or their center lines shall be offset at least 200 feet.
      (15)   Streets shall have the names of existing streets which are in alignment or which connect directly to the end of a street. There shall be no duplication of street names within the area. All street names shall be approved by the County Planning Commission. Permanent signs shall be installed by the developer at his or her expense at the time of installation of other off-site public improvements.
      (16)   Curvature and alignment.
         (a)   All horizontal curves shall comply with AASHTO Standards for desired speeds.
         (b)   All vertical curves shall comply with AASHTO Standards for desired speeds.
         (c)   Where a subdivision abuts a highway, frontage roads may be required for the safety of the public.
      (17)   Roadbed construction. Minimum roadbed grading and paving for County streets and roads shall be according to AASHTO Standards.
      (18)   Road grades. All roads and street grades shall be designed in compliance with AASHTO Standards and approved by the County Public Works Director.
      (19)   Block standards. Block lengths shall be reasonable as approved by the County Public Works Director, and in total design shall provide for safe, convenient access and circulation for the general public and emergency vehicles as per fire code.
   (D)   Easement standards.
      (1)   Easements shall follow rear and side lot lines whenever practical and shall have a minimum total width of fifteen feet apportioned equally in abutting properties except where the gradient or terrain may require additional space for working or maintenance of the easement.
      (2)   Where front-line easements are required, a minimum of 15 feet shall be allocated as a utility easement. Perimeter easements shall not be less than 15 feet in width, extending throughout the peripheral area of the development, if required by the Planning Commission.
      (3)   All easements shall be designed so as to provide efficient installation of utilities, design features or street planning.
      (4)   The Planning Commission may require the exterior perimeter of any subdivision to be fenced if the need is apparent to protect the health, safety, and welfare of the residents or others.
      (5)   Unless the Planning Commission and County Commission determine, upon application by a subdivider, supported by recommendation of the County Public Works Director, that it is not feasible to do so, all power lines, telephone lines, and other utility lines shall be placed underground by the subdivider.
   (E)   Alleys. The County Planning Commission may approve service access to the interior of blocks in certain instances, in which case alleys shall be indicated on the plan and plat.
   (F)   Culinary water system standards.
      (1)   Culinary water systems shall meet the requirements of the Southwest Utah Public Health Department and the State of Utah.
      (2)   Prior to final subdivision approval, the proposed culinary water system plans and specifications (improvement drawings), including water quantity and quality, shall be approved by the Local Health Department or the DEQ, as applicable.
      (3)   Hauling water to a proposed subdivision to meet the water and fire protection requirements of this chapter is prohibited and shall not be accepted by the county as a method of providing any subdivision with water and fire protection services.
      (4)   Culinary water supply.
         (a)   The subdivider shall provide a piped, public or private culinary water supply to the property line of every lot in any subdivision.
         (b)   Said system shall be designed and built to safe drinking water standards as evidenced by written approval from the State of Utah.
         (c)   The culinary water system and plans shall also be approved by the Local Health Department, DEQ, Fire Marshall and County Building Official before approval is issued.
   (G)   Wastewater system standards.
      (1)   The Local Health Department and/or DEQ shall review and approve the proposed wastewater treatment method and submit its approval in writing with the application for preliminary plat approval. It shall be the responsibility of the applicant to provide information and materials as required by the Local Health Department or DEQ, as applicable, necessary to evaluate the proposed sewage treatment method.
      (2)   Connection to an existing public sewer system, with adequate sewer treatment capacity, is required for all subdivisions and individual lots, if public sewer lines are within 300 feet of the borders of the subdivision or any lot to be developed within the un-incorporated lands of the county or as dictated by state law.
      (3)   If connection to an existing public sewer system is not authorized, the applicant shall present an alternative, that has been approved by the Local Health Department or DEQ in writing, to the Planning Commission with the preliminary application.
      (4)   Based upon the recommendations of the Building Official, Zoning Administrator and local health department or DEQ, the Planning Commission may recommend, and the County Commission may require, the installation of a private central wastewater system, and/or the provision of sewer lines (dry sewer), necessary to facilitate the connection of the proposed subdivision to a central sewer system at a later date.
      (5)   In all cases where a proposed subdivision is not to be connected to an approved public sewer system, approval for the proposed sewage treatment method shall be obtained from the Local Health Department or the DEQ, as applicable.
      (6)   For all proposed subdivisions, or subdivision phases, where onsite wastewater disposal systems are proposed, the preliminary subdivision application shall include written approval from the Health Department for each lot proposed.
      (7)   Larger lots than those provided by the Zoning District in which the proposed subdivision is located, may be required by the county to assure that each lot will provide adequate onsite sewer treatment. The location of the approved absorption site shall be shown and identified clearly on the preliminary subdivision plat.
      (8)   Septic tanks and/or sealed vaults or other alternative treatment methods may be approved only when an existing public sanitary sewer system is more than 300 feet from the nearest boundary of the lot or the nearest boundary of a proposed subdivision. Written approval from the Local Health Department or DEQ shall be required for all forms of wastewater disposal.
      (9)   When individual on-site wastewater systems are proposed, the lot owner shall install such facilities at the time the principal building is constructed, and no building permit shall be issued until such installation is assured and approved by the Building Official.
      (10)   In all other cases, wastewater disposal facilities shall be provided for every lot or parcel that is to be used for residential or commercial building.
   (H)   Flood plain standards.
      (1)   All subdivisions and buildings within a flood plain shall be the responsibility of the subdivider and not the county.
      (2)   No subdivision in the county shall be allowed in a flood plain unless each lot is situated where there is sufficient area for the location of a dwelling entirely outside the flood plain, and where all setback requirements of the zone in which the subdivision is located, can be met.
      (3)   Flood plains shall be determined according to the latest FEMA flood maps.
   (I)   Storm drainage standards.
      (1)   Complete drainage systems for the entire subdivision area shall be designed by a professional engineer, licensed in the state of Utah and qualified to perform such work, and shall be shown graphically. All existing drainage features which are to be incorporated in the design shall be identified. If the final plat is to be presented in phases, a general drainage plan for the entire area shall be presented with the first phase, and appropriate development stages for the drainage system for each phase indicated.
      (2)   The drainage system shall be designed by a registered engineer who shall certify that it has been done according to professional drainage standards. The subdivider shall be responsible for the results and performance of the drainage system.
      (3)   The drainage system shall be designed by the subdivider to consider the drainage basin as a whole and shall accommodate not only runoff from the subdivision area but also accommodate the runoff from those areas adjacent to and “upstream” from the subdivision itself, as well as its effects on lands downstream.
      (4)   All proposed surface drainage structures shall be indicated on the plans.
      (5)   All appropriate designs, details, and dimensions needed to explain clearly proposed construction materials and elevations shall be included in the drainage plans.
   (J)   Fire protection. 
      (1)   All subdivisions shall have a fire protection plan prepared by qualified individuals and approved by the state, county, or community fire officials as the case may be prior to approval of any subdivision or development within the county.
      (2)   The fire protection plan shall apply to all lands that are to be developed as well as any properties adjacent to and that might otherwise be impacted by the possibility of fire.
      (3)   The following shall be a minimum to be included in the plans:
         (a)   Fire flow needs to protect all properties to be located in the development to a minimum fire protection rating;
         (b)   Source, availability, amount, and delivery of water necessary to meet fire flow requirements;
         (c)   Responsibility, training, and availability of personnel for maintenance and operation of required firefighting infrastructure and equipment; and
         (d)   Written approval of the fire protection plan of all related fire officials;
      (4)   The fire protection plan shall be submitted with the preliminary plat application and be considered as an integral part of the subdivision plat approval process.
      (5)   In the case of remote cabin sites, a minimum of 1,000 gallons of water storage shall be required for fire protection for each dwelling during and following construction. It shall be the responsibility of the respective property owners to ensure that this provision is met.
      (6)   The county shall not be liable for any action taken by the subdivider as a result of this chapter.
(Ord. 2021-10, passed 9-27-2021)
Statutory reference:
   State law provisions, see UCA § 17-27a-7