A. 
Steep or unstable land and areas having inadequate drainage shall not be subdivided into building lots unless the subdivider makes adequate provisions to prevent the same from endangering life, health or other property.
B. 
Any lands subject to flooding or any natural drainage channels shall not be platted as building lots unless adequate provisions to eliminate or control flood hazards in the subdivision or on other affected lands are made by the subdivider and approved by the city.
C. 
Outstanding natural and cultural features such as scenic spots, watercourses and historic sites and buildings shall be preserved insofar as possible.
(Prior code § 24-19)
A. 
Streets on a subdivision plat shall conform to the master street plan or the comprehensive plan, where applicable.
B. 
All streets shall be aligned to join with planned or existing streets.
C. 
All streets shall be designed to bear a logical relationship to the topography of the land.
D. 
Intersections of streets shall be at right angles unless otherwise approved by the city.
E. 
Only residential culs-de-sac will be permitted, the design of which shall be evaluated by the time of development, based on land use and density, etc.
F. 
Except as provided above for culs-de-sac, no dead-end streets shall be permitted except in cases where such streets are designed to connect with future streets on adjacent land in which case a suitable turn-around easement at the end thereof may be required. Such turn-around easement shall not be required if no lots in the subdivision are dependent on such street for access.
G. 
Double frontage and reversed frontage lots shall be avoided except where necessary to provide separation of residential development from traffic arterials or to overcome specific disadvantages of topography and orientation.
H. 
Lots shall not, in general, derive access exclusively from a major or secondary street. Where driveway access from a major or collector street may be necessary for several adjoining lots, the planning commission may require that such lots be served by a combined access drive in order to limit possible traffic hazards on such street. Where possible driveways should be designed and arranged so as to avoid requiring vehicles to back into traffic on major or collector streets.
I. 
Each subdivider and/or developer shall be required to furnish and install fences wherever the planning commission determines that a hazardous condition may exist. The fences shall be constructed according to standards established by the city and shall be noted as to height and material on the final plat. No certificate of occupancy shall be issued until such fence improvements have been duly installed.
J. 
Reverse curves on major arterial streets shall be joined by a tangent at least 200 feet in length, or as approved by the community development director.
K. 
The subdivider will not be permitted to reserve a strip for the purpose of controlling access to such street from such property, except with the permission of the city and, in any event, only if the control of such strip is given to the city.
L. 
Street, alley and easement right-of-way widths shall meet the following standards:
Classification
Minimum Right-of-Way Width
Major arterial streets
100 feet
Sub-arterial streets
80 feet
Collector streets (rural and urban)
60 feet
Residential streets (rural and urban)
50 feet
Industrial streets
60 feet
Marginal access streets
40 feet
Alleys (where permitted)
20 feet
Side yard easements
5 feet
Rear yard easements
7 1/2 feet
All other easements as necessary
Variable
The full width of any street shall be dedicated and half-streets shall not be permitted.
M. 
Alleys and other easements shall be controlled by the following requirements:
1. 
Alleys in residential subdivisions shall not be permitted except in cases when the same are necessary and desirable to continue an existing pattern.
2. 
Alleys shall be provided in commercial and industrial areas unless other provisions are made and approved for service access.
3. 
Easements of such widths as necessary shall be provided on each side of all rear lot lines and along the side lot lines as necessary for utilities. Where alleys are permitted, they may be used as a substitute for such easements.
4. 
Storm drainage easements and retention sites shall be provided as required and approved by the city.
5. 
The subdivider shall be responsible for adequate provisions to eliminate or control flood hazards associated with the subdivision. Agreements concerning stormwater drainage between private parties shall be subject to city review and approval.
6. 
Easements of such widths as necessary shall be provided on each lot as necessary when water for irrigation purposes will be provided within the subdivision.
N. 
Street Design Criteria.
-Image-2.tif
-Image-3.tif
-Image-4.tif
-Image-5.tif
-Image-7.tif
-Image-6.tif
-Image-8.tif
-Image-10.tif
-Image-9.tif
(Prior code § 24-20; Ord. 17-017 § 1, 2017; Ord. 18-002 § 1, 2018)
All blocks in a subdivision shall not exceed a length of one thousand three hundred and twenty feet (1,320). Blocks exceeding 1,000 feet in length shall provide a pedestrian right-of-way of not less than 10 feet in width. Improved walks of not less than five feet in width shall be placed within the above right-of-way.
(Prior code § 24-21)
A. 
No lot in a subdivision shall have less area than required under applicable zoning requirements of the city.
B. 
Each lot shall provide vehicular access to a public street.
C. 
Lots with both a front and rear frontage on a street shall not be permitted except where necessary to provide separation from major arterial streets or from incompatible land uses.
D. 
Side lot lines shall be substantially at right angles or radial to street lines.
(Prior code § 24-22)
All curb ramps, ramps, and sidewalks located within and subject to the jurisdiction of the city shall comply with the minimum guidelines for design set forth in the Americans with Disabilities Act Accessibility Guidelines (ADAAG), July 26, 1991, and any successor editions. The city shall utilize ADAAG in setting appropriate design requirements.
(Prior code § 24-23; Ord. 18-004 § 1, 2018)
A. 
If irrigation water is to be made available in a subdivision, it shall be the responsibility of the subdivider to install an approved delivery system. Such a system shall meet minimum delivery requirements for the subdivision. Further, the system shall encompass the control of wastewater, drainage water and surface water.
B. 
The subdivider may elect one of the following irrigation systems to provide irrigation water to lots and other areas within the subdivision. Maintenance of such systems shall be the responsibility of the users.
1. 
Open concrete lined ditches;
2. 
Underground pipe gravity flow system;
3. 
Underground pressurized system.
(Prior code § 24-24)
A. 
A subdivider shall be required to dedicate rights-of-way for public streets, drainage easements and utility easements as needed to serve the area being platted. In cases where any part of an existing road is in the tract being subdivided, the subdivider shall dedicate such roadway to the minimum width required under this chapter for such street. This shall include perimeter roads.
B. 
Reservation of sites for flood control purposes and other municipal uses shall be mutually agreed upon between the subdivider and the city council.
(Prior code § 24-25)
A. 
General Requirements. The planning commission shall not recommend for approval any plat of subdivision which does not make adequate provision for stormwater or floodwater runoff channels or basis. The stormwater drainage system shall be separate and independent of any sanitary sewer system. Storm sewers, where required, shall be designed by the rational method, or other methods as approved by the city, and a copy of design computations shall be submitted along with plans.
B. 
Natural or Stormwater Facilities.
1. 
Location. The applicant may be required by the planning commission to carry away by pipe or open ditch any spring or surface water that may exist either prior to, or as a result of, the subdivision. Such drainage facilities shall be located in the road right-of-way where feasible, or in perpetual unobstructed easements of appropriate width, and shall be constructed in accordance with the construction standards and specifications.
2. 
Accessibility to Public Storm Sewers.
a. 
Where a public storm sewer is accessible, the applicant shall install storm sewer facilities or, if no outlets are within a reasonable distance, adequate provision shall be made for the disposal of stormwaters, subject to the specifications of the city of Riverton. However, in subdivisions containing lots less than 15,000 square feet in area and in business and industrial districts, underground or surface storm sewer systems shall be constructed throughout the subdivisions and be conducted to an approved out-fall.
b. 
If a connection to a public storm sewer will be provided eventually, as determined by the city and the planning commission, the developer shall make arrangements for future stormwater disposal by a public utility system at the time the plat receives final approval. Provisions for such connection shall be incorporated by inclusion in the performance agreement required for the subdivision plat.
3. 
Accommodation of Upstream Drainage Areas. A culvert or other drainage facility shall in each case be large enough to accommodate potential runoff from its entire upstream drainage area, whether inside or outside the subdivision. The city shall determine the necessary size of the facility, based on the provisions of the construction standards and specifications assuming conditions of maximum potential watershed development permitted by Title 17.
4. 
Effect on Downstream Drainage Areas. The city staff shall also study the effect of each subdivision on existing downstream drainage facilities outside the area of the subdivision. City drainage studies, together with such other studies as shall be appropriate, shall serve as a guide to needed improvements. Where it is anticipated that the additional runoff incident to the development of the subdivision will overload an existing downstream drainage facility, the planning commission may withhold approval of the subdivision until provision has been made for the improvement of such potential condition in such sum as the planning commission shall determine. No subdivision shall be approved unless adequate drainage will be provided to an adequate drainage watercourse or facility.
5. 
Areas of Poor Drainage. Whenever a plat is submitted for an area which is subject to flooding, the planning commission may approve such subdivision, provided that the applicant fills the affected area of such subdivision to an elevation sufficient to place the elevation of streets and lots at a minimum of 12 inches above the elevation of the maximum probable flood, as determined by the city. The plat of such subdivision shall provide for an overflow zone along the bank of any stream or watercourse in a width which shall be sufficient in times of high water to contain or move the water, and no fill shall be placed in the overflow zone nor shall any structure be erected or placed therein. The boundaries of the overflow zone shall be subject to approval by the city.
6. 
Floodplain Areas. The planning commission may, when it deems it necessary for the health, safety or welfare of the present and future population of the area and necessary to the conservation of water, drainage and sanitary facilities, prohibit the subdivision of any portion of the property which lies within the floodplain of any stream or drainage course. These floodplain areas shall be preserved from any and all destruction or damage resulting from clearing, grading or dumping of earth, waste material or stumps, except at the discretion of the planning commission.
C. 
Dedication of Drainage Easements.
1. 
General Requirements. Where a subdivision is traversed by a watercourse, drainageway, channel or stream, there shall be provided a stormwater easement or drainage right-of-way conforming substantially to the lines of such watercourse, and of such width and construction or both as will be adequate for the purpose. Wherever possible, it is desirable that the drainage be maintained by an open channel with landscaped banks and adequate width for maximum potential volume of flow.
2. 
Drainage Easements.
a. 
Where topography or other conditions are such as to make impractical the inclusion of drainage facilities within road right-of-way, perpetual unobstructed easements at least 15 feet in width for such drainage facilities shall be provided across property outside the road lines and with satisfactory access to the road. Easements shall be indicated on the plat. Drainage easements shall be carried from the road to a natural watercourse or to other drainage facilities.
b. 
When a proposed drainage system will carry water in excess of historic flows across private land outside the subdivision, appropriate drainage rights must be secured and indicated on the plat.
c. 
Low-lying lands along watercourses subject to flooding or overflowing during storm periods, whether or not included in areas for dedication, shall be preserved and retained in their natural state of drainageways. Such land or lands subject to periodic flooding shall not be computed in determining the number of lots to be utilized for average density procedure nor for computing the area requirement of any lot.
(Prior code § 24-26; Ord. 18-002 § 9, 2018)
A. 
The applicant shall install sanitary sewer facilities in a manner prescribed by the city construction standards and specifications. All plans shall be designed in accordance with the rules, regulations and standards of the city and department of environmental quality (DEQ).
B. 
All land uses within the city and planning jurisdiction involving a density of one unit per acre or more shall be required to develop a collection system and central sewage disposal facility or connect to the municipal system when located within one-half mile of such system. Where public sanitary sewerage systems are not reasonably accessible but will become available within a reasonable time, the applicant may choose one of the following alternatives:
1. 
Central sewerage system, the maintenance and operating costs to be assessed against each property benefited. Where plans for future public sanitary sewerage systems exist, the applicant shall install the sewer lines, laterals and mains to be in permanent conformance with such plans and ready for connection to such public sewer mains. Minimum line size shall be eight inches in diameter;
2. 
Individual disposal system.
(Prior code § 24-27)
A. 
General Requirements.
1. 
Necessary action shall be taken by the applicant to extend or create a water-supply district for the purpose of providing a water-supply system capable of providing domestic water use and fire protection.
2. 
Where a city water main is located within one-half mile of the subdivision, the subdivider shall install adequate water facilities (including fire hydrants) subject to the specifications of the state and city. All water mains shall be at least six inches in diameter.
3. 
Water main extensions shall be approved by the officially designated agency of the state and city.
4. 
To facilitate the above, the location of all fire hydrants, all water supply improvements and the boundary lines of proposed districts, indicating all improvements proposed to be served, shall be shown on the preliminary plat and the cost of installing the same shall be included in the performance agreement to be furnished by the developer.
B. 
Individual Wells and Central Water Systems.
1. 
In low-density developments, involving densities of one unit per two and one-half acres or less, in the discretion of the planning commission, if a public water system is not available within one-half mile of the subdivision individual wells may be used or a central water system provided in such a manner that an adequate supply of potable water will be available to every lot in the subdivision.
2. 
If the planning commission requires that a connection to a public water main shall be eventually provided as a condition to approval of an individual well or central water system, the applicant shall make arrangements for future water service at the time the plat received final approval. Performance or case bonds may be required to insure compliance.
C. 
Fire Hydrants. Fire hydrants shall be required for all subdivisions when adequate water systems have been required. Fire hydrants shall be located no more than 500 feet apart in rural areas, within 250 feet of any residential structure in urban areas and 300 feet apart in commercial and industrial areas, and shall be approved by the applicable protection unit. To eliminate future street openings, all underground utilities for fire hydrants, together with the fire hydrants themselves and all other supply improvements shall be installed before any final paving of a street shown on the subdivision plat.
(Prior code § 24-28)