Inclusion In Improvement Plan: The placement, size and type of all required improvements shall be shown in the improvement plan accompanying a preliminary subdivision application. Such improvement plan shall include engineering drawings relating to the improvements.
Required Improvements: The following improvements are required for all subdivisions and development in the City, unless specifically waived by ordinance or the Land Use Authority. All improvements shall meet minimum City standards for design and quality of materials and shall be installed in accordance with minimum City standards and specifications and current APWA standard plans and specifications, as directed by the City.
1. Improvements: All streets shown on the final plat for dedication to the City and any existing street, whether or not shown on the final plat, which is contiguous and provides access to any lot in a subdivision shall be improved in conformance with the applicable cross section and construction standards as set forth in the City development and construction standards.
2. Asphalt Layer Thickness: All streets shall be installed with a two and one-half inch (2.5") three and on half inch (3.5") or as stated in city standards surface layer of asphalt at the time of initial development construction. At such a time that ninety percent (90%) or more of the lots have been permitted for site construction, or not more than two (2) years from the date of initial performance guarantee, the developer shall be responsible for any and all street repairs necessary and the installation of a one inch (1") slurry seal on all parts of all roads in and associated with the subdivision. At no time shall a street in a subdivision be completed with a street surface asphalt layer being thinner than three and one-half inches (3.5") total thickness unless otherwise specified in code.
3. Street Grade: No major collector/arterial street shall have a grade of more than eight percent (8%) and no local street shall have a grade of more than ten percent (10%), except that the Planning Commission may approve up to an additional two percent (2%) grade for short stretches of roadway where, in its opinion, the eight percent (8%), ten percent (10%) standards would result in undesirable extra earthwork or circuitous routes and that the proposed steep grade section will not result in the establishment of a hazardous condition. It is the responsibility of the developer to present evidence that the additional allowance in grade is desirable. The City Engineer shall provide recommendations regarding hazardous conditions and any other concerns on the proposed steep grade sections.
4. Prior to the start of any subdivision improvements, the developer shall:
a. Submit a traffic control plan for review and approval by the City Engineer;
b. Hold a pre-construction meeting with City Staff and all contractors;
c. Provide written notification to all property owners within three hundred feet (300') of the subdivision boundaries; and
d. Install all required construction entrance improvements as specified in subsection 10-15C-2O.
1. Sidewalks; Compliance: Sidewalks shall be provided along both sides of streets, at the developer's expense, and in compliance with the detailed performance standards of the "City of Elk Ridge Construction Specifications and Standards". Sidewalks are "required improvements", subject to the guarantee provisions of chapter 16 of this title.
a. Additionally, sidewalks, trails and gutters must be installed along the back of lots that back onto a street where such improvements are required.
2. Sidewalks; Infill Areas/Agricultural Zones: Sidewalks may not be required in infill areas not required to have curb and gutter. They are also not required in agricultural zones. The Planning Commission can require sidewalk in infill or agricultural zones if deemed appropriate. Such determination may be made if lot sizes, traffic patterns, wider roads or other related design factors support installation of sidewalks. If the Planning Commission does not require sidewalks, the Planning Commission may specify the completion of other public facilities in lieu of sidewalks.
3. Sidewalks; Placement: Notwithstanding other provisions of this title, the city council may determine in a development agreement that sidewalks will not be required on one or both sides of the street. Such determination may be made if lot sizes, traffic patterns, wider roads or other related design factors support a more flexible approach.
4. Improved Trails: Developments shall provide any planned trails for bicycle/pedestrian use which connect the development to other public facilities such as parks or the major existing and planned trails established in the City's General Plan or other officially adopted trail map of the City. The trail requirement also is extended to cul-de-sacs that require a trail easement connecting neighborhoods. Trails are required improvements, subject to the guarantee provisions of this title.
a. Trail placement must conform to the city's adopted Trails Map, which is a part of the City's General Plan. Any proposed trail placement that deviates from the Trails Map will require an amendment to the map. As part of the General Plan, any such amendment must undergo review and approval by the Planning Commission, followed by City Council approval.
b. Trail surfaces must conform to the surfacing indicated on the adopted City Trails map. Any proposed changes to the surfacing type will be considered a modification to the General Plan and must be submitted for review and approval by the Planning Commission, followed by the City Council approval.
c. All trail surface must be six inch (6") deep concrete or prepared base and ten feet (10') wide.
C. Culinary Water System:
1. The subdivider shall be responsible for installing all off site and on-site water mains. All on site mains shall be installed in such a way that each lot shall be served therefrom. All water mains shall extend to the boundaries of the subdivision.
2. All water mains shall be sufficient in size to provide a volume of flow and level of pressure adequate for culinary use (in accordance with state and city standards) and fire protection purposes (in accordance with the city fire code); provided, that no water main shall be less than eight inches (8") in diameter.
3. Water service laterals shall be installed from the main line to each adjacent lot. The service lateral shall consist of: a) the corporation stop adjacent to the main line; b) the lateral pipe running from the main to the adjacent lot; and c) the stop and waste valve, meter box and meter setter located within the boundary of the lot.
4. All mains and laterals shall be constructed prior to the installation of road base and hard surfacing of the road and curb and gutter, where such is required.
5. The subdivision water system shall be connected to a water supply facility (source, reservoir and delivery system) which is capable of delivering adequate flows for both culinary and fire purposes.
6. The type and quality of materials, location and placement of pipes and other particulars relating to design and construction of the system shall be in accordance with the city development and construction standards.
1. All subdivisions shall have fire hydrants installed at locations approved by the fire chief and city engineer.
2. Fire hydrants shall be installed in accordance with city standards, as determined by the city engineer.
1. Both off site and on-site sewer mains of not less than eight inches (8") in diameter shall be installed in such a way that each lot in the subdivision will be connected thereto.
2. Separate sewer service laterals shall be installed from the main to each adjacent lot.
3. All new development must connect to the city sanitary sewer collection system at the time of construction.
4. The quality of materials, location and placement of pipes and other particulars relating to design and construction of the system shall be in accordance with the city development and construction standards.
F. Permanent Survey Markers: Permanent survey monuments shall be installed in each subdivision. The location of the monuments shall be as required by the city engineer and shall be shown on the final plat. Also, all corners of the subdivision and all lot corners in the subdivision shall be marked.
G. Electric, Telephone And Natural Gas: Electric power, telephone and natural gas shall be provided to each lot. All lines and appurtenant facilities shall be located a minimum of thirty-six inches (36") underground, except when approved by the Planning Commission upon a finding that compliance with the standard set forth herein is not practically feasible.
H. Street Signs: Street signs shall be installed at all locations indicated on the preliminary plan. After final all required signs shall conform to city standards and be provided and installed by the developer at the expense of the developer.
I. Environmental Hazards: Adverse environmental conditions must be eliminated or accommodated as follows:
a. The placement of streets, buildings and the designation of building sites on areas of unstable soils shall be prohibited.
b. Soils with a significant erosion hazard shall be protected. Revegetation or other erosion control measures may be imposed as a condition of subdivision approval.
2. Surface Water Disposal:
a. To the maximum extent possible, surface water produced from the subdivision development shall be properly disposed of within the limits of the subdivision. If not possible within the limits of the development, alternative disposal methods off site may be considered as approved by the city engineer.
b. Pipes, manholes, sumps and other facilities for the collection, transport and disposal of surface water shall be installed where required by the city. The location, size and design of said facilities and any easements relating thereto, shall be in accordance with the city stormwater disposal plans and standards or as directed by the city engineer.
c. The location of all facilities and easements shall be shown on the plans, plats and engineering drawings, as applicable.
d. All plans for subdivision or development shall identify the location of all existing natural drainage channels and final plats of subdivision, and similar land development projects shall provide a drainage easement which includes the natural channel.
e. No structure shall be located less than thirty feet (30') from the boundary of any designated drainage channel and the layout of any subdivision or similar development project which contains a natural drainage channel shall be so arranged to ensure that all required building setbacks can be maintained.
f. Facilities for stormwater runoff shall be required to be constructed on development sites and according to the following design standards:
(1) Such facilities shall be the first improvement of facilities on the property. Phasing of drainage facilities may be allowed as approved by the city engineer.
(2) All storm drain catch basins, pipes and manholes shall be designed to collect and convey stormwater runoff from the twenty five (25) year, twenty four (24) hour storm.
(3) In the event that a documented downstream discharge or storage with available capacity is present, detention basins shall be designed to detain runoff from the twenty five (25) year, twenty four (24) hour storm with a maximum discharge rate equal to the predevelopment discharge rate. In addition, the stormwater plan shall make provisions for the accommodation of flows during a one hundred (100) year storm event in a manner that will minimize damage to personal property.
(4) Retention facilities such as sumps and retention ponds shall be designed to retain runoff from the one hundred (100) year, twenty four (24) hour storm.
(5) The design storm criteria shall be as follows:
g. Multipurpose stormwater storage facilities or ponds which incorporate recreational facilities such as sport fields, playgrounds and gathering areas are encouraged. Such facilities must incorporate underground rock galleries or connected sumps which disperse nuisance waters under the surface of the pond or recreation facility. The pond must also be tiered in such a way that water from a 25-year storm event is contained in a lower tier. Only major storms larger than a 25-year event should reach the upper tier where recreational facilities may be located. All storage facilities whether they incorporate recreational facilities or not must be designed to the following criteria:
(1) Maximum side slope on the inside of a pond to be three horizontal to one vertical (3:1) for ponds up to two feet (2') deep, four horizontal to one vertical (4:1) for ponds three (3') to four feet (4') deep and five horizontal to one vertical (5:1) for ponds over four feet (4') deep.
(2) Ponds over two feet (2') deep must be approved by the City Engineer. Safety measures such as fencing may be required as well as additional landscaping.
(3) Maximum slope on the outside of a pond to be two horizontal to one vertical (2:1).
(4) The City Engineer shall determine the required access for maintenance for the ponds.
(5) A landscape plan shall be submitted to the city for review and approval. All stormwater facilities are to be landscaped appropriate to the design criteria and surrounding properties.
(6) In the case of detention ponds, an emergency overflow spillway shall be incorporated into the design assuming the outlet is inoperable and the inflow exceeds the outlet capacity.
(7) Percolation tests used for design shall be certified by a geotechnical engineer.
(8) All detention and retention basins to be designed to drain within a twenty-four (24) hour period.
(9) All ponds are to be designed with a minimum of one foot (1') of freeboard or fifty percent (50%) capacity increase, whichever is less.
(10) Each development is unique with varying surfaces and areas. The runoff coefficient for the rational method shall be estimated based on the following values listed in Table 2 of this section.
h. Ownership and maintenance of storage facilities will be determined on a case-by-case basis by the Planning Commission. If ponds are proposed to be owned and maintained by the city, they must incorporate recreational facilities and be a minimum of one acre in size. The City engineer approves the access for maintenance of ponds.
i. All stormwater facilities shall incorporate oil and sediment separators in the system prior to release into a pond or infiltration facility.
j. Storm drain pipelines shall be located within the public right of way or a minimum fifteen foot (15') wide dedicated easement. Pipelines outside of public rights of way shall also require access and maintenance easements as directed by the city engineer. The minimum pipe size shall be twelve inches (12"). Acceptable pipe materials include HDPE, reinforced concrete and nonreinforced concrete.
k. All proposed development shall submit storm drainage calculations prepared by a licensed engineer in the state of Utah. Acceptable analysis methods include the rational method, TR55 and HEC HMS.
l. All drainage facilities shall be designed to divert surface water away from cut surfaces or sloping surfaces of a fill.
a. All subdivision proposals shall be consistent with the need to minimize flood damage.
b. The subdivision layout must make adequate provision for natural drainage channels and floodways.
c. All water, sewer and other utility systems and facilities located in designated flood areas shall be designed and constructed to minimize flood damage, including the infiltration of floodwater into the system, or discharge of the system into the floodwaters.
J. Irrigation Water System: All subdivision plans shall recognize and accommodate the irrigation system within the city, including, as necessary, the installation of culverts and pipes, the rerouting of ditches and the reconstruction of head gates. All canals, ditches and other watercourses which lie within or are contiguous to a proposed subdivision shall not be interfered with by the subdivider without complying with the requirements of Utah Code Annotated section 73-1-15, as amended, and the applicable provisions of this development code.
K. Other: Where applicable, other adverse environmental conditions must also be eliminated or adequately accommodated. The additional conditions shall include, but not be limited to, seismic, landslide and groundwater. (Ord. 97-7-8-8, 7-8-1997; amd. Ord. 01-12-11-19, 12-11-2001, eff. 1-11-2002; Ord. 06-14, 10-10-2006; Ord. 06-19, 11-28-2006; Ord. 12-7, 11-27-2012; Ord. 24-04, 12-10-2024)