The standards and details of design contained herein are intended only as minimum requirements so that the general arrangement and layout of a subdivision, survey or buildable parcel(s) may be adjusted to a wide variety of circumstances. However, in the design and development of buildable lots or parcels, the applicant should use standards consistent with the site conditions so as to assure an economical, pleasant and durable development. Approval of land divisions by specific quantity description or plat of survey for buildable parcels that do not meet the requirements of this section may be denied by the Zoning Administrator. Approval of plats of subdivision or minor plats of subdivision that do not meet the requirements of this section may be denied by the Zoning Commission or Board of Supervisors.
1. Streets. The general requirements for streets are as follows:
A. Comprehensive Plan. All proposed plats and subdivisions shall conform to the Comprehensive Plan of Marion County. If any overall plan or neighborhood plan has been made by the Commission for the area in which the proposed subdivision is located, the street system of the latter shall conform in general thereto.
B. No Landlocked Parcels. No parcels or remnant parcels shall be created via plat of survey or subdivision that do not have a means for access for future development purposes. Buildable lots or parcels created after the effective date of this ordinance shall have frontage to a public or private street. Lots or parcels designated for agricultural purposes only may have access from an adjoining parcel under the same ownership.
C. Continuation of Existing Streets. Proposed streets shall provide for continuation or completion of any existing streets (constructed or recorded) in adjoining property, at equal or greater width, but no street right-of-way shall be less than sixty-six (66) feet in width, and in similar alignment, unless variations are recommended by the Commission.
D. Circulation. The street pattern shall provide ease of circulation within the subdivision as well as convenient access to adjoining streets, thoroughfares, or unsubdivided land as may be required by the Commission. In a case where a street will eventually be extended beyond the plat, but is temporarily dead ended, an interim turnaround may be required.
E. Street Intersections. Street intersections shall be as nearly at right angles as possible.
F. Cul-de-sacs. Whenever a cul-de-sac is permitted, such street shall be provided at the closed end with a turnaround having a street property line diameter of at least one hundred fifty (150) feet in the case of the residential subdivision. The right-of-way width of the street leading to the turnaround shall be a minimum of sixty-six (66) feet for private streets and sixty-six (66) feet for public streets. The property line at the intersection of the turnaround and the lead-in portion of the street shall be rounded at a radius of not less than seventy five (75) feet. Where the cul-de-sac is a public street, said public street shall not be longer than 660 feet.
G. Street Names. All newly platted streets, whether public or private, shall be addressed in a manner consistent with the present street addressing system. A proposed street that is obviously in alignment with other existing streets, or with a street that may be logically extended, although the various portions be at a considerable distance from each other, shall bear the same name. Names of new streets shall be subject to the approval of the Commission in order to avoid duplication or close similarity of names.
H. Physical and Cultural Features. In general, streets shall be platted with appropriate regard for topography, creeks, wooded areas, and other natural features which would lend themselves to attractive treatment.
(1) Storm drainage facilities shall be designed and constructed in conformance with the Statewide Urban Design Standards and Specifications (SUDAS).
I. Half Streets. Dedication of half streets will be discouraged. Where there exists a dedicated or platted half street or alley adjacent to the tract to be subdivided, the other half shall be platted if deemed necessary by the Commission.
J. Alleys. Alleys may be required in business areas and industrial districts for adequate access to block interiors and for off-street loading and parking purposes. Except where justified by unusual conditions, alleys will not be approved in residential districts. Dead-end alleys shall be provided with a means of turning around at the dead end thereof.
K. Easements.
(1) Right-of-Way Easements.
(a) An easement for the benefit of Marion County shall be provided for all public streets before same will be accepted for County maintenance.
(b) Major public thoroughfares shall have a minimum right-of-way as specified by the County Engineer. Minor or residential public streets shall not be less than sixty-six (66) feet wide.
(c) Private residential streets shall have a minimum right-of-way easement width of sixty-six (66) feet. An easement shall be provided for the benefit of all property owners having access via a private street, with maintenance of the private street the responsibility of all such property owners by means of a recorded legal document. The private street right-of-way easement shall not be included in the “net” acres of any lot or parcel.
(d) In no case shall a private right-of-way or roadway easement for a private street be located on a separate lot.
(2) Utility Easements. Easements for utilities shall be provided along rear or side lot lines or along alleys, if needed.
(3) Drainage Easements. Whenever any stream or important surface water course is located in an area that is being subdivided, the subdivider shall, at said owner’s own expense, make adequate provision for straightening or widening the channel so that it will properly carry the surface water, and shall provide and dedicate to Marion County an easement along each side of the stream, which easement shall be for the purpose of widening, improving, or protecting the stream. The width of such easement shall be not less than twenty (20) feet and the total width of the easement shall be adequate to provide for any necessary channel relocation or straightening. It shall not be the responsibility of Marion County to repair embankments, remove fallen trees, or replace vegetation as a result of erosion, construction, farm operations or similar causes.
(4) Property owner or tenant shall not erect any permanent structures in any right-of-way, drainage way or easement, or utility easement, but shall have the right to make any other use of the land subject to such easement which is not inconsistent with the rights of the grantee.
L. Unsubdivided Portion of Plat. Where the land division to be submitted includes only part of the tract owned by the subdivider, the Zoning Administrator or Commission may require topography and a sketch of a tentative future street system of the developed portion.
M. Major Thoroughfares. Where a new subdivision, except where justified by limiting conditions, involves frontage on a trafficway, limited access way, freeway, or parkway, the street layout shall provide motor access to such frontage by one of the following means:
(1) A parallel street supplying frontage for lots backing onto the trafficway.
(2) A series of cul-de-sacs or short loops entered from and planned at right angles to such a parallel street, with their terminal lots backing onto the highway.
(3) An access drive separated by a planting strip from the highway to which motor access from the drive is provided at points suitably spaced.
(4) A service drive or alley at the rear of the lots. Where any one of the above-mentioned arrangements is used, deed covenants or other means should prevent any private residential driveways from having direct access to the trafficway.
(5) Where improvements to existing public farm to market roads or federal aide routes are necessary, including turning lanes or pavement widening, the pavement surface shall be designed in accordance with IDOT or SUDAS Standards fitting the design traffic needs and shall be approved by the County Engineer.
(6) Where access to any public or private street within the subdivision or to any lot or parcel with the plat is from any highway or street under the jurisdiction of the Iowa Department of Transportation, (DOT) no plat of survey or plat of subdivision shall be finally approved until all necessary entrance permits have been obtained from the Iowa DOT.
N. New Subdivision Streets. Where a proposed subdivision requires or proposes a new street within the development, the following shall apply:
(1) All roads and related infrastructure including but not limited to pavement, curb, storm sewers and culverts shall remain private until such time as the County Engineer recommends acceptance and the Marion County Board of Supervisors accepts such facilities and right-of-way in accordance with Section 56.11 herein.
(2) Completion of the subdivision shall not compel the County to maintain any portion of the infrastructure.
(3) No subdivision shall be approved unless access to all lots is available from an improved public or private road.
(4) No individual road within a subdivision, including all phases of the subdivision, shall be eligible to be a County-maintained public road until the entire subdivision including all phases is completed to the standards in place at the time of the completion of each phase of the final improvements to the subdivision.
(5) Pavement width, thickness and materials for private residential roads shall be in accordance with Marion County’s current policy on “Hard Surface Improvement of Roads” as adopted by the Board of Supervisors, unless said pavement width and materials has been waived in accordance with Subsection 56.07(1)(P) of this chapter.
O. Sidewalks. Sidewalks may be required by the Board of Supervisors at the time of final platting along any public or private street in the subdivision in accordance with standards and specifications of Marion County. Where streets include curb and gutter, sidewalks shall be located within the right-of-way if sidewalks are required. Where streets do not include curb and gutter, sidewalks shall be located within an easement adjacent to the right-of-way if sidewalks are required. When sidewalks are required, they shall be constructed in conjunction with the principal structure on the adjoining lot.
P. Consent and Waiver. In subdivisions where a majority of lots are not less than one hundred (100) feet in width, along streets designated for single-family use, the Zoning Commission may waive the following requirements, upon recommendation of the County Engineer, at the time of consideration of the preliminary plat. If such subdivision is within the jurisdictional limits of a city, the applicable city must also waive said requirements.
(1) Pavement Surface. In said subdivisions, the Commission may waive the requirement for concrete paving for private streets, in which case the type and strength of street surfacing to be installed shall be noted on the preliminary plat and final plat.
(2) Curb and Gutter. In said subdivisions and where conditions are such as to discourage street parking, the Commission may waive the requirement for curb and gutter in which case a typical section of the roadside ditches shall be added to the preliminary plat.
(3) Sidewalks. Where the buildable parcels have frontage on public or private streets not having curb and gutter, the Commission or Zoning Administrator may waive the requirement for sidewalks.
(4) Streetlights. In subdivisions not having streets with curb and gutter, the Commission may waive the requirement for streetlights.
(5) In the event facilities are proposed by the subdivider that do not meet the minimum standards described by this chapter and/or are not in conformance with the Secondary Road Department Subdivision Policy, each lot or tract within said subdivision shall have a consent and waiver approved by the Commission with the preliminary plat and approved by the Board and recorded with the final plat stating that the cost for any improvements to bring the private street up to minimum standards shall be the responsibility of the property owner(s).
Q. Access. Any new land division fronting on a public trafficway shall have no more than four (4) accesses onto each side of such trafficway in each 1,320 feet; provided however that approved field drives shall not be considered. All accesses shall be placed only at the direction of the Marion County Engineer. No access drive shall be permitted to a County public road in a subdivision where access is available to a private road within a subdivision.
R. Street Grades. Public streets shall be completed to grades which have been officially determined or approved by the County Engineer. All public and private streets shall be graded to the full width of the right-of-way and adjacent side slopes graded to blend with the natural ground level. The maximum grade for all streets shall be designed in accordance with the Statewide Urban Design Standards and Specifications (SUDAS). All changes in grades on major roads or highways shall be connected by vertical curves in accordance with SUDAS.
The grade alignment and resultant visibility, especially at intersections, shall be worked out in detail to meet the approval of the County Engineer.
S. Railroads. If a railroad is involved, the subdivision plan should:
(1) Be so arranged as to permit, where necessary, future grade separations at highway crossings of the railroad.
(2) Border the railroad with a parallel street at a sufficient distance from it to permit deep lots to back onto the railroad; or form a buffer strip for park, commercial, or industrial use.
(3) Provide cul-de-sacs at right angles to the railroad so as to permit lots to back thereunto.
T. Erosion Control. It shall be the responsibility of the property owner and/or the subdivider to obtain any necessary permits prior to commencing construction, including but not limited to a NPDES Storm Water Discharge Permit and preparation of a Storm Water Pollution Prevention Plan (SWPPP).
U. Street Trees. Trees or bushes shall not be planted within the public street or road right-of-way.
2. Utilities. All new water supply and distribution systems and all new sanitary sewer collection and treatment systems shall comply with the requirements of Marion County Environmental Health Department and the Iowa Department of Natural Resources, whether said systems are individual systems or common systems.
A. Common Systems. A common water and wastewater system shall be provided for any subdivisions or developments having lots less than 3.0 acres in size or for multiple-family dwellings, row houses, mobile home parks, commercial uses or industrial uses unless specifically waived by Marion County Environmental Health Department.
B. Easements. Easements shall be provided as required in paragraph 1(K) of this section.
3. Blocks. The general requirements for blocks shall be as follows:
A. No block shall be longer than 1,320 feet, except in areas zoned residential districts by the Zoning Ordinance.
B. At street intersections, block corners shall be rounded with a radius of not less than twenty-five (25) feet; where, at any one intersection, a curve radius has been previously established; such radius shall be used as standard.
4. Lots. The general requirements for lots shall be as follows:
A. Corner lots shall be of such width as to permit the maintenance of all yard requirements as may be required by the Zoning Ordinance.
B. Double frontage lots should be avoided except where essential to provide separation of development from major traffic arteries or to overcome specific disadvantages of topography.
C. Side lot lines shall be approximately at right angles to the street or radial to curved streets. On large size lots and except when indicated by topography, lot lines shall be straight.