The following supplemental information shall be required unless the Board of Commissioners approves a variance request submitted by the subdivider to waive specific requirements. The submissions identified below are to include the number of paper copies indicated (inclusive of one original) plus one electronic copy (submitted by disk, email, or other electronic media approved by the Planning Official).
(A) Soil erosion and sediment control plan: two paper copies. Each copy shall contain the following:
(1) A scaled topographic survey map of the proposed subdivision site showing proposed lot lines and two-foot contour intervals;
(2) A soil erosion control plan showing locations and areas of anticipated soil disturbance and the proposed erosion control structures and practices that will be used to control the anticipated erosion;
(3) A sediment control plan detailing the structures and practices that will be applied to control sediment generated by on-site erosion;
(4) A seeding and planting plan for any screening strips or other landscaped areas required by the Board of Commissioners;
(5) Evidence of acceptance of the subdivider’s application onto the State National Pollution Discharge Elimination System (NPDES) permit by DENR; and
(6)
A soils engineering report and/or an engineering geology report may be requested by the Board of Commissioners when unstable soils or steep slopes are present within or adjacent to the subdivision.
(7) Subdivision improvements required by type.
(a) High Density subdivisions shall be required to have the following (10,000 + sq. ft): Geotechnical soil borings must be completed by a geotechnical engineer with one soil boring hole at a depth of at least 15 feet deep per every 12 lots unless otherwise recommended that additional depth or additional soil borings based on soil conditions are needed by the geotechnical engineer.
(b) Modified High Density subdivisions shall be required to have the following (one to three acres): Geotechnical soil borings must be completed by a geotechnical engineer with one soil boring hole at a depth of at least 15 feet deep per every six lots unless otherwise recommended that additional depth or additional soil borings based on soil conditions are needed by the geotechnical engineer.
(c) Medium Density subdivisions shall be required to have the following (three to nine acres): Geotechnical soil borings must be completed by a geotechnical engineer with one soil boring hole at a depth of at least 15 feet deep per every four lots unless otherwise recommended that additional depth or additional soil borings based on soil conditions are needed by the geotechnical engineer.
(d) Commercial subdivisions shall be required to have the following: Geotechnical soil borings must be completed by a geotechnical engineer with one soil boring hole at a depth of at least 25 feet deep per every lot unless otherwise recommended that additional depth or additional soil borings based on soil conditions are needed by the geotechnical engineer.
(e) Multi-residential subdivisions shall be required to have the following (one + acres): Geotechnical soil borings must be completed by a geotechnical engineer with one soil boring hole at a depth of at least 25 feet deep per every four lots unless otherwise recommended that additional depth or additional soil borings based on soil conditions are needed by the geotechnical engineer.
(B) Water distribution plan: four paper copies.
(1) Two of the copies are meant to be used for review by the Planning Department, the Public Works Official, and the City Engineer. Two of the copies are to be submitted to DENR by the subdivider’s engineer for review and comment after review by city staff.
(2) Each copy shall contain the following:
(a) A scaled plan and profile drawing showing the location and size of the water distribution system including such features as pipes, valves, fittings, hydrants, high pressure pumping equipment, pressure reduction valves, and the locations and methods proposed for connection to the community water system; and
(b) A scaled drawing showing the location and size of the service tap for each lot.
(C) Sanitary sewer plan: four paper copies.
(1) Two of the copies are meant to be used for review by the Planning Department, the Public Works Official, and the City Engineer. Two of the copies are to be submitted to DENR by the subdivider’s engineer for review and comment after review by city staff.
(2) Each copy shall contain the following information:
(a) A scaled plan and profile drawing of the proposed subdivision’s sanitary sewer system showing the location and size of all existing and proposed sewer facilities in and adjacent to the subdivision; and
(b) The direction of flow of each sewer main; the location and type of each manhole and other sewerage system appurtenance, including lift stations, treatment plants, and connection locations to the city’s sanitary sewer system; and the service tap location and method for each lot.
(D) Stormwater management plan: two paper copies.
(1) The plan shall provide stormwater management for the entire subdivision and each block within the subdivision.
(2) Each copy shall contain the following information:
(a) A scaled plan and profile drawing of the location of existing and proposed drainage ways, detention structures, streams, and water features in and adjacent to the subdivision with a notation of the direction of water flow through the subdivision;
(b) The location of easements and rights-of-way for drainage ways and maintenance access thereof;
(c) The location, size, and invert elevations of proposed drainage structures, such as culverts, bridges, pipes, drop inlets, and headwalls;
(d) A report on both pre- and post-development runoff within and through the subdivision;
(e) The area of land contributing runoff to each drainage structure;
(f) A report on the capacity of downstream drainage structures and channels and the effects of the proposed subdivision’s development on downstream capacities; and
(g) All stormwater management structures and conveyances shall be designed to accommodate a 100-year, 24-hour design storm.
(E) Utility distribution plan: two paper copies.
(1) This shall include gas, electric, cable, and telephone utilities.
(2) Each copy shall contain the following information:
(a) A scaled plan and profile drawing showing the location of gas mains, street lights, electric lines, telephone lines, cable television lines, and facilities as necessary to serve each lot within the subdivision and, where necessary, adjacent property; and
(b) A scaled map showing required easements, including anchor easements for guy wires.
(F) Street plan: two paper copies.
(1) This shall be used for review by the Planning Department, the Public Works Official, and the City Engineer. Additional copies may be required for review by the County Highway Superintendent(s) or the South Dakota Department of Transportation (SDDOT) Rapid City Region Engineer.
(2) Each copy shall contain the following information:
(a) A plan and profile drawing of the location and names of all streets in and adjacent to the proposed subdivision, the widths and areas of existing and proposed rights-of-way, the locations, dimensions, and areas of all parks and dedications, and the location of all required sidewalks, curbs and gutters, drop inlets, gang mailboxes, street name and traffic control signage, bike or walking paths, crosswalks, and curb cuts;
(b) A notation of any major street that is identified in the major street plan; and
(c) The topography of the subdivision at two-foot contour intervals, unless a smaller contour interval is requested by the City Engineer, showing the location of streets and rights-of-way.
(3) The Board of Commissioners may require that a traffic impact study be prepared for a large subdivision.
(G) Street maintenance plan: two paper copies.
(1) This shall be submitted for all plats within the extraterritorial platting jurisdiction of the city to provide evidence that a legal entity will provide the mechanism for street maintenance and snow removal on all proposed subdivision streets.
(2) Each copy shall include one or more of the following documents:
(a) An agreement with the county indicating that the proposed street will be accepted by the county for road maintenance and snow removal;
(b) Evidence that a Road District has been established in accordance with SDCL Ch. 31-12A;
(c) An agreement to be approved by the Board of Commissioners which guarantees sufficient financial commitment to provide these services; and
(d) A written request to be approved by the Board of Commissioners for a waiver based upon one or more of the following:
1. The proposed subdivision includes four or fewer lots and resubdivision is unlikely under existing zoning or covenants;
2. Unusual topographic restraints which would prevent acceptance of the street for public maintenance; or
3. Other unique circumstances proposed to the Board of Commissioners.
(Ord. #115, passed 2-16-2017; Ord. 2022-07, passed 7-7-2022)