A. Streets:
1. Arrangement:
a. The arrangement of streets in new subdivisions shall make provision for the continuation of the existing streets in adjoining areas and shall provide access to unsubdivided adjoining areas in so far as such continuation or access shall be deemed necessary by the planning and zoning commission. The new street must connect with existing public streets.
b. The street arrangement should be such as to cause no unnecessary hardship to owners of adjoining property when they plat their own land and seek to provide for convenient access to it. If the adjoining land is zoned for residential use, streets shall be located so that the adjacent land may be most efficiently subdivided. Half streets, consisting of half of a standard road right of way width and half of a fully developed street, on the boundary of a subdivision are prohibited. Sharing of road development costs with abutting property owners and recovery of same is provided for with a protection strip as described in section 10-4-8 of this title.
2. Road Right Of Way Widths: Major and collector streets shall conform to the width designated on the master street plan wherever a subdivision is in an area for which a master street plan has been adopted. For territory where such street plan has not been completed at the time the subdivision preliminary plat is submitted to the planning and zoning commission, streets shall be provided as required by the planning and zoning commission, with minimum widths of ninety feet (90') for collector streets and extensions of existing ninety foot (90') wide streets, and sixty feet (60') for minor streets. Minor streets serving cul-de-sacs only, shall have a minimum width of fifty feet (50').
3. Stub Streets: Stub streets shall be collector streets provided where needed to connect to adjacent undeveloped land and new streets and must be provided where needed to connect to existing stub streets in adjacent subdivisions. Not more than six (6) lots shall front on a stub street, except where a temporary cul-de-sac turnaround is provided.
4. Cul-De-Sacs: Cul-de-sacs (dead end streets) not more than six hundred fifty feet (650') long and serving no more than ten (10) lots, whichever is more restrictive, shall be used only where unusual conditions exist which make other designs undesirable. Each cul-de-sac must be terminated by a turnaround of not less than one hundred feet (100') in diameter, and the face of curb or pavement edge radius shall be forty feet (40') or more. If surface water drainage is into the turnaround due to the grade of the street, necessary catch basins and drainage easements shall be provided. All temporary cul-de-sacs or dead end streets shall be provided with a turning area at the dead end thereof satisfying the foregoing requirements and shall be available for public use as long as the dead end condition exists.
5. Road Obstructions And Termination: In the event that any road or street in any subdivision shall terminate at or within fifty feet (50') of any ditch, canal, creek, waterway or other obstruction which will, at the opinion of the city engineer, require a bridge or other structure in order to continue the road over or across the canal, ditch, creek, waterway or other obstruction, the subdivider shall deposit with the city a sum of money equal to one-half (1/2) of the city engineer's estimate of the cost for constructing a proper and suitable bridge over the same. The city engineer shall, on request, furnish the subdivider a cost breakdown for any such structure. At such time, in the opinion of the governing body, as it becomes desirable to construct such structure, the same shall be constructed by the city applying such deposit toward the construction costs and charging the other one-half (1/2) of such cost to the person developing the opposite side of such obstruction, or if there is no person so developing the other side, the one-half (1/2) shall be borne as a city expense.
6. Frontage On Major Highways: Where a residential subdivision abuts a major highway, frontage roads may be required.
7. Street Names: Streets shall have the names of existing streets which are in alignment. There shall be no duplication of street names within the area. All street names must be approved by the planning and zoning commission, and opportunity shall be given the city recorder for review and recommendation prior to the approval of street names by the planning and zoning commission.
8. Design Criteria:
a. No more than four (4) streets shall enter an intersection.
b. Streets shall intersect at ninety degrees (90o), except where otherwise approved as necessary by the planning and zoning commission.
c. The centerlines of two (2) subordinate streets meeting a through street from opposite sides shall extend as a continuous line, or the centerlines shall be offset at least one hundred fifty feet (150').
9. Curvature And Alignment:
a. To ensure adequate sight distances, street roadway line connections shall be made by horizontal curves. The minimum centerline radius for minor streets shall be one hundred fifty feet (150') and all other streets shall be three hundred feet (300'). On collector and major streets, a minimum tangent of one hundred feet (100') shall be required between a curve and street intersection; a minimum tangent of one hundred feet (100') shall be required between reverse curves.
b. Vertical curves shall be used at all changes of grades exceeding one percent (1%) and shall be designed to provide minimum sight distances of two hundred feet (200') for minor streets and three hundred feet (300') for all other streets, except that vertical curves for major streets shall be as determined by the current specifications of the state department of transportation (UDOT). The minimum acceptable horizontal length of vertical curves from beginning of the vertical curve to the end of the vertical curve is two hundred feet (200') for collector and minor streets and three hundred feet (300') for major streets.
10. Street Grades: All street grades shall be designed as follows:
a. Major and collector streets shall be limited to a maximum grade of eight percent (8%). Sustained grades shall be limited to five percent (5%).
b. Minor streets shall be limited to a maximum grade of ten percent (10%). Sustained grades shall be limited to seven percent (7%).
c. Cul-de-sacs with a negative grade progressing toward the turnaround shall be limited to a maximum grade of six percent (6%). The cul-de-sac shall terminate with a grade not to exceed three percent (3%) for the last one hundred feet (100') of traveled surface. The cul-de-sac shall be limited to a maximum length of six hundred fifty feet (650') and have adequate easement for drainage.
d. Street intersections shall have a vertical alignment such that the grade shall not exceed three percent (3%) for a minimum distance of fifty feet (50') each way from the centerline of the intersection.
e. Maximum grades shall be approved only when accompanied by changes to a lesser grade, and where length of that portion of that road at maximum grade is less than six hundred feet (600').
f. Streets in mountainous terrain shall be designed at less than maximum allowable grade in order that they can be safely negotiated and that snow can be removed during winter.
11. Shoulders And Pavement:
a. Four foot (4') shoulders shall be provided where curbs are waived. Design shall comply with city construction standards.
b. Pavements shall be designed in accordance with the procedures promulgated by the state department of transportation and contained in part 8 "materials", of their manual of instruction. The subdivider's engineer shall submit his design calculations and supporting data with the final plat. The minimum base thickness is eight inches (8"). The minimum acceptable pavement thickness is two and one-half inches (21/2"). All pavements shall be seal coated during following construction season. The seal coat shall comply with the UDOT standard specification for bituminous seal coat type A.
12. Sidewalk, Curbs And Gutters:
a. Sidewalks, curbs and gutters shall be provided on streets to be dedicated to the public, unless waived by the planning and zoning commission. Sidewalks, curbs and gutters may be required by the governing body on existing streets bordering the subdivision. Minimum grade of streets and curb-gutter is four-tenths percent (0.4%).
b. All curb corners shall have a radius of not less than twenty five feet (25').
c. On curb returns, at least one additional control point for elevation besides those at points of curvature shall be established. Control points shall be staked in the field to ensure drainage of intersections.
d. Curbs and gutters on all urban streets shall be concrete of the standard high back type design being thirty inches (30") wide from back of curb to lip of gutter and not less than six inches (6") thick where the curb abuts the street pavement. The top of the curb shall be approximately three and one-half inches (31/2") higher in elevation than the lip of the gutter.
B. Easement Standards:
1. Easements shall follow rear and side lot lines whenever practical and shall have a minimum total width of twenty feet (20'), apportioned equally (10 feet on each side) to abutting properties.
2. Where front lot line easements are required, a minimum of ten feet (10') shall be allocated as a utility easement. Perimeter easements shall be not less than fifteen feet (15') in width, extending throughout the peripheral area of the development, as required by the planning and zoning commission.
3. All easements shall be designed so as to provide efficient installation of utilities or street planting. Special guying easements at corners may be required if any utilities are to be overhead. Public utility installation shall be located so as to permit multiple installations within the easements. The subdivider shall establish final utility grades prior to utility installation.
4. Whenever any stream or important surface drainage course is located in an area that is being subdivided, the subdivider shall dedicate an adequate easement along each side of the stream for the purpose of widening, deepening, sloping, improving or protecting the stream from drainage, parkway or recreational use.
5. The planning and zoning commission shall, unless waived for good and sufficient cause, require that easements for drainage through a subdivision and adjoining property be provided by the subdivider.
C. Utilities Underground:
1. Unless the planning and zoning commission and governing body determine, upon application by the subdivider, supported by recommendation of the city engineer, that it is not feasible to do so, all power lines, telephone lines and other normally overhead utility lines shall be placed underground by the subdivider.
2. The subdivider, by designating the location for easements for all utility lines and installations thereof, shall agree, as one of the conditions for the approval of any plan, that he will at his own expense remove any obstruction that, in the opinion of the city engineer, makes such location impracticable for use until the obstruction is removed or altered. If additional expense is required for underground installation of power or other utility, the subdivider shall agree to pay any additional expense occasioned thereby and sign an agreement with the city for the purpose of carrying out this requirement to completion.
D. Blocks:
1. Blocks shall not exceed one thousand three hundred feet (1,300') in length. Blocks over eight hundred feet (800') in length shall be provided with a dedicated walkway through the block at its approximate center. Such walkways shall be not less than ten feet (10') in width. The width of blocks generally shall be sufficient to allow two (2) tiers of lots. Blocks intended for business or industrial uses shall be designed specifically for such purposes with adequate space set aside for off street parking and delivery facilities.
2. Property lines at all street intersections shall be rounded with curves having a minimum radius of fifteen feet (15').
E. Lots:
1. The lot arrangement and design shall be such that lots will provide satisfactory and desirable sites for buildings and be properly related to topography and to existing and probable future requirements.
2. All lots shown on the subdivision plan must conform to the minimum requirements of the zone in which the subdivision is located, and to the minimum requirements for sewage disposal.
3. Each lot shall abut on a street dedicated by the recording of a subdivision or on an existing publicly dedicated street, or on a street which has become public by right of use and is at least fifty feet (50') wide, or on a private street approved by the planning and zoning commission and the governing body.
4. Double frontage lots are prohibited unless approved by the planning and zoning commission for reasons of topography.
5. No wedge shaped lot shall be less than thirty feet (30') in width at the front property line, or less than the lot frontage at the front setback line required in the zoning district, whichever is larger.
6. Side lot lines shall be at right angles or radial to street lines, except where justified by the subdivider and approved by the planning and zoning commission.
7. Corner lots shall have extra width sufficient for maintenance of required building lines on both streets.
8. All remnants of lots below minimum size left over after subdividing of a larger tract must be added to adjacent lots, rather than allowed to remain as unusable parcels.
9. Where the land covered by a subdivision includes two (2) or more parcels in separate ownership and the lot arrangement is such that a property ownership line divides one or more lots, the land in each lot so divided shall be transferred by deed to either single or joint ownership before approval of the final plat, and such transfer certified to the planning and zoning commission by the city recorder.
10. No single lot shall be divided by a municipal or county boundary line.
11. A lot shall not be divided by a road, alley or other lots.
F. Storm Drainage And Floodplains: Complete drainage systems for the entire subdivision area shall be designed by a professional engineer, licensed in the state 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 so identified. If the final plat is to be presented in phases, a general drainage plan for the entire area shall be provided with the preliminary plat, and appropriate development stages for the drainage system for each section indicated.
1. The drainage and floodplain systems shall be designed to:
a. Permit the unimpeded flow of natural watercourses.
b. Ensure adequate drainage of all low points.
c. Ensure application of the following regulations regarding development in designated floodplains.
2. The use of land in floodplains shall be limited as follows:
a. Construction of buildings shall not be permitted in a designated floodway with a return frequency of one hundred (100) years or more.
b. Building construction may occur in that portion of the designated floodway where the return frequency is less than one hundred (100) years; provided, the main floor space is constructed above the designated maximum probable flood level, and provisions are made in the design and construction of the buildings to prevent entry of floodwaters into the lower levels.
c. Where floodway velocities are generally determined to be under five feet (5') per second and maximum flood depth will not exceed three feet (3'), such uses as cultivated agriculture, nurseries, parks and recreation facilities and accessory parking may be permitted.
d. Any use of land is prohibited where flooding would create a public health hazard or problem. This includes shallow wells, uncased deep wells, sanitary landfills, septic tank and on lot sewage disposal systems, water treatment plants and sewage disposal systems not completely protected from inundation.
e. Any contemplated floodplain encroachment or channeling shall be thoroughly analyzed and its effect on stream flow determined before such encroachment is undertaken. Any construction, dumping and filling operations in a designated floodway constitutes an encroachment and must be approved by the city engineer and the planning and zoning commission before any work is done.
f. No lot one acre or less in area shall include floodplains. All lots more than one acre shall contain not less than twenty thousand (20,000) square feet of land which is at an elevation at least one foot (1') above the elevation of 100-year recurrence interval flood or, where such data is not available, three feet (3') above the elevation of the maximum flood record.
3. The design of the storm system shall:
a. Consider the drainage system as a whole and shall include:
(1) Runoff from the subdivision area.
(2) Where applicable, the system shall be designed to accommodate the runoff from those areas adjacent to and "upstream" from the subdivision.
(3) The effects of the storm waters on lands downstream.
(4) Limit peak runoff discharge from any new development area to 0.2 cfs per acre. Detention ponds with discharge control structures shall be used to store storm water runoff in excess of the peak permissible discharge.
b. Include all facilities necessary to accommodate that quantity of water attributable to a storm having a minimum 10-year frequency.
(1) Gutter capacities will be limited to that flow which will not create a hazard, damage or flood adjacent properties and which can be safely intercepted at the inlets.
(2) Storm water inlets and catch basins shall be provided within the roadway improvements at points approved by the city engineer.
(3) No ditch or canal shall be approved as suitable for the disposal of storm drainage water without the written permission of the appropriate ditch, canal company or of the water users of said ditch or canal. No ditch or canal shall be used for storm water disposal unless adequately improved to handle such water as might be reasonably expected to flow in the canal or ditch as irrigation water, the subdivision runoff water, and any other water expected to reach such canal or ditch. No ditch, canal or other waterway shall be permitted within property dedicated or to be dedicated for public use except as specifically approved by planning and zoning commission and governing body. The subdivider shall remove such waterways from property to be dedicated before the submission of the final plat.
(4) Complete design calculations shall be submitted with the plans for the storm sewer system.
G. Sewage Disposal: Except as otherwise provided below, the subdivider shall provide, or have provided, a piped sanitary sewage system to the property line of every lot in the subdivision. The sewage system shall meet the minimum standards and requirements of the district sanitarian, the state division of environmental health and this code.
1. Sanitary Sewer Mains, Laterals And House Connections:
a. All sewer mains shall be a minimum of eight inches (8") in diameter and shall be designed with adequate capacity for the current and future development.
b. All sewer laterals and house connections shall be a minimum of four inches (4") in diameter.
c. Where local, county and regional master plans indicate that construction or extension of sanitary sewers may serve the subdivision area within a reasonable time, the planning and zoning commission may require the installation and capping of sanitary sewer mains and house connections by the subdivider, in addition to the installation of temporary individual on site sanitary disposal systems.
2. On Site Sewage Disposal:
a. Septic tank systems and drain fields are generally not permitted, unless specifically provided for in unusual conditions in the city sewer ordinance 1 . Properties situated east of the Malad River may be permitted to use on site sewage disposal systems if approved by the planning and zoning commission.
b. Whenever individual septic tanks are proposed as sanitary sewage disposal systems, the subdivider shall either install such facilities or require by deed restrictions, or otherwise, as a condition of the sale of each lot or parcel within such subdivision, that on lot sanitary sewage disposal facilities be installed by the purchaser of said lot at the time the principal building permit shall be issued, until such installation is assured.
c. Each subdivided lot to be served by an on site soil absorption sewage disposal system shall contain an adequate site for such system and shall meet minimum requirements of the Utah department of health regulations for individual wastewater disposal systems and must be approved, in writing, by the district sanitarian. In general, unless specifically required by said health department requirements, an adequate site requires a minimum depth of eight feet (8') from the surface of the ground to impermeable bedrock, and a minimum depth of six feet (6') from the surface of the ground to the ground water surface (based on annual high water level). Each site must also be at least one thousand five hundred feet (1,500') from any shallow water supply well and one hundred feet (100') from any stream or watercourse, and at least two hundred feet (200') from any major live stream; at least ten feet (10') from any dwelling or property line and shall not be subject to flooding or inundation.
H. Water Of Sufficient Quantity Obligation Of Subdivider: Where connection to the existing culinary water system is not feasible and a private noncommunity water system is proposed to serve a subdivision development, the procurement of water, whether by purchase of water rights, water shares, exchange or service agreement, shall be the responsibility of the subdivider. Water shall be provided for the exclusive use of the subdivision in an amount sufficient to meet the following flow standards, unless it can be proved to the planning and zoning commission that a lesser amount is adequate:
1. Separate System Not Available: Where a separate secondary water system is not available for each lot:
a. A minimum of two hundred ninety two thousand (292,000) gallons per year per dwelling unit for the first ten thousand (10,000) square feet of lot area. Approximately two-thirds (2/3) of this water shall be available for use during the months of May through October. Each additional ten thousand (10,000) square feet of lot area shall require an additional two hundred twenty five thousand (225,000) gallons, which shall be available for use during the months of May through October.
b. The distribution system shall be designed to deliver the above quantities of water at a minimum pressure of forty (40) psi. In no case shall the capacity of the system be less than 1.6 gallons per minute per dwelling unit in addition to the water required for fire suppression.
2. Separate System Available: Where a separate secondary water system is available at each lot:
a. A minimum of one hundred forty six thousand (146,000) gallons per year per dwelling unit.
b. The distribution system shall be designed to deliver the above quantity of water at a minimum pressure of forty (40) psi. In no case shall the capacity of the system be less than 1.6 gallons per minute per dwelling unit in addition to the water required for fire suppression.
3. Design Calculations: When requested, complete design calculations shall be furnished to the city engineer.
I. Culinary Water System: Where connection to the existing community water system is feasible and required, the culinary water system for the subdivision shall meet the following requirements:
1. Requirements: The culinary water facility shall extend to the property line of every lot and shall be capable of delivering the flows required in subsection H of this section. All water mains shall be a minimum of six inches (6") in diameter, except in cul-de-sacs where the diameter may be four inches (4") if no fire hydrant is connected to the pipe. The storage capacity of reservoirs shall provide a minimum of one thousand one hundred (1,100) gallons for each dwelling unit in addition to the required storage for fire suppression.
2. Fire Hydrants: Fire hydrants shall be installed in accordance with the regulations of the city fire department and in no case:
a. Connected to a pipe less than six inches (6") in diameter.
b. Located more than seven hundred feet (700') from any other fire hydrant.
c. Located such that any single dwelling unit would be more than three hundred fifty feet (350') from the nearest fire hydrant when measured along the most probable access route.
3. Construction Standards: Water line construction shall comply with the city construction standards.
J. Secondary Water Systems:
1. Availability: When a pressurized secondary water system for irrigation is located within three hundred feet (300') of the subdivision boundary, and secondary water rights are available to the property from said secondary water system, to be subdivided, it shall be piped to the subdivision and made available for the full and beneficial use of each lot owner.
2. Identification: All pressure irrigation systems in a proposed subdivision shall be identified and otherwise color coded, as to pipe and valve color, to meet state standards and regulations.
3. Adequate Capacity: The capacity of the pipe system shall be adequate to serve the demand of the subdivision.
4. Approval Of Plans And Specifications: Plans and specifications for the system must be approved, in writing, by the agency furnishing the water and the city engineer.
5. Turnouts Or Valves Required: Turnouts or valves must be located on each lot.
6. Open Ditches:
a. Where an existing irrigation system consisting of open ditches is located on or adjacent to a proposed subdivision, complete plans for relocation or covering and other safety precautions shall be submitted with an application for preliminary approval of a plat.
b. The open ditches or canals shall not be allowed within or adjoining a subdivision, except when fenced along rear or side lot lines. The subdivider shall work with irrigation, drainage or ditch companies regarding:
(1) Methods of covering, realigning or eliminating ditches or canals within or adjoining the subdivision.
(2) The size of pipe and culverts required.
c. The responsibility for the periodic inspection, cleaning and maintenance of such ditches, pipes and culverts, in cases where canals or ditches cross public roads or proposed public roads, specifications and grades for pipe or culvert must be approved by the city engineer.
K. Safety Fences: The subdivider shall install a six foot (6'), nonclimbable chainlink fence, or its equivalent, along all open ditches, canals or waterways, nonaccess streets, open reservoirs or bodies of water, railroad right of way and other such features of potentially hazardous nature, crossing or contiguous to the property being subdivided, except on those features which the planning and zoning commission shall determine would not be a hazard to life. (Ord., 2-29-1996)
Notes
| 1 | 1. See title 7, chapter 2 of this code. |