(A) When required; submission generally.
(1) Whenever the owner of any tract or parcel of land within the corporate limits of the city or within one mile of its corporate limits wishes to make a subdivision of the property, he or she shall cause to be prepared a preliminary plat of the subdivision and shall submit six copies of the preliminary plat along with other information prescribed in this chapter to the clerical staff of the Engineering Department who upon receipt shall place the request on the next scheduled Plan Commission agenda for its preliminary study and action.
(2) The Commission may waive in full or in part the requirements that a preliminary plat be filed under any of the following conditions:
(a) A plat consisting of one lot;
(b) A plat where the subdivider’s entire tract is included within a final plat filed with the Commission; and
(c) A replat.
(B) Application for preliminary approval; submission; contents; fee. A subdivider desiring preliminary approval of a plat of a subdivision of any land lying within the city, shall submit a written application therefor to the Commission. The application form provided by the city shall be accompanied by six copies of the following information and plans:
(1) A location map which need not be a special drawing; the date may be shown on available city maps. The location map shall show:
(a) The subdivision name and its location;
(b) Major thoroughfares related to the subdivision;
(c) Title, scale, north point and date.
(2) A site map showing:
(a) Contours at intervals of two feet, if the general slope of the site is less than 10%, and at vertical intervals of five feet if the general slope is greater than 10%; and
(b) Terrain features, wooded areas, buildings and other natural or artificial features which would affect the plan of the subdivision;
(c) Tract boundary lines, showing dimensions, bearings, angles and references to section, township and range lines or corners;
(d) Streets and right-of-way on or adjoining the site, including dedicated widths, roadway widths, approximate gradients, types and width of pavements, curbs, driveways, location of streetlights, sidewalks, tree planting and other pertinent data;
(e) Easements, including locations, widths and purposes;
(f) Utilities, including sanitary and storm sewers, other drainage facilities; water lines; gas mains; electric utilities and other facilities. The size or capacity of each should be shown and the locations of distance to each existing utility indicated;
(g) The location of street light standards;
(h) The zoning of the site and adjoining property;
(i) Existing or proposed platting of adjacent land within 200 feet of the subdivision;
(j) Other features or conditions which would affect the subdivision favorable or adversely;
(k) Title, scale, north point and date; and
(l) Location and elevation of all benchmarks. All vertical datum shall be based on the 1912 Geodetic Survey. Benchmarks are available at the City Engineer’s office. The 1929 Geodetic Survey shall be used to establish elevation certificates.
(3) A preliminary plat of the subdivision, drawn to scale of 50 feet to one inch or 100 feet to one inch; however, if the resulting drawing would be over 36 inches in shortest dimension, a scale as recommended by the City Engineer or the Commission may be used. The preliminary plan shall show:
(a) The proposed name of the subdivision;
(b) The names and addresses of owner, the subdivider and the city planner, land planning consultant, engineer or surveyor, who prepared the plan;
(c) A street pattern showing the names, which shall not duplicate names of other streets in the community except in cases of extensions of existing streets, and the widths of rights-of-way of streets, and widths of crosswalks, easements or alleys;
(d) The layout of the lots, showing dimensions and numbers. The square foot area of each lot with irregular sides and are not rectangular; the block number, if required and distances, radii and chords;
(e) The parcels of land proposed to be dedicated or reserved for schools, parks, playgrounds or other public, semipublic or community purposes;
(f) The building setback or front yard lines;
(g) The key plan legend and notes; and
(h) The scale, north point and date.
(4) The information called for in divisions (B)(2) and (3) of this section may be submitted as one or two maps or plans;
(5) Preliminary exterior elevations showing design and specifying exterior materials;
(6) Preliminary engineering plans showing:
(a) Profiles, typical cross sections and specifications for proposed street improvements;
(b) Profiles, locations and other explanatory data concerning the installation of storm sewer systems, and public, quasi-public or private sanitary sewerage and/or water distribution systems; and
(c) All private sanitary sewer systems shall have the prior approval of the City Engineer that the system will be compatible for connection to a public sanitary sewer outlet when available;
(7) A description of the protective covenants or private restrictions to be incorporated in the plat of the subdivision;
(8) Information as to any agreements which have been entered into with the owners of other property within the neighborhood in which the proposed subdivision is located, as to general plans for the entire neighborhood. Reference should be made to the comprehensive plan for suggestions as to the general street pattern and design of the neighborhood. Wherever possible all of the property owners within the neighborhood should endeavor to agree upon a general plan for its development, in order that the subdivision may be designed as an integral part of a well-considered overall plan; and
(9) The application shall be accompanied by a filing fee (certified check or money order) payable to the city in the amount of $250. A review fee shall also be charged to compensate the city for actual time and material costs incurred to review and approve the preliminary plat. No part of these fees shall be returnable to the applicant. The City Administrator shall have the ability to waive the filing fee for any 501(c)(3), non-profit entity.
(C) Submission of preliminary plat. Whenever the owner of any tract or parcel of land within the corporate limits of the city or within one mile of its corporate limits wishes to make a subdivision of the property, he or she shall cause a preliminary plat of the subdivision to be prepared and shall submit six copies of the preliminary plat along with the other information prescribed in this chapter to the clerical staff of the Engineering Department who upon receipt shall place the request on the next scheduled Planning Commission agenda for its preliminary study and actions.
(D) Time limit on preliminary approval. Approval of the preliminary plat shall be effective for a period of 18 months unless, upon request of the applicant, the Council grants and extension. The final plat shall be submitted to the Clerk and, if it is not received within 18 months, all previous actions by the Council with respect to the plat shall be deemed to be null and void.
(E) Conformance required. The preliminary plat of the subdivision shall conform to the principles and standards of design established in this chapter, including plats located within one mile of the city corporate limits.
(F) Comprehensive plan. The subdivision plan shall conform to the principles and standards which are generally exhibited in the comprehensive plan.
(G) Street and alleys.
(1) Proposed streets should be adjusted to the contour of the land so as to produce usable lots and streets of reasonable gradient.
(2) The street and alley layout shall conform to the street plan for the development of the neighborhood in which the proposed subdivision is located and shall provide access to all lots and parcels of land within the subdivision. Where streets cross other streets, jogs shall not be created. The minimum distance between centerlines of parallel, or approximately parallel, streets intersecting a cross street should be 125 feet.
(3) Certain proposed streets, where appropriate, shall be extended to the boundary line of the tract to be subdivided so as to provide for normal circulation of traffic within the vicinity.
(4) Wherever there exists a dedicated or platted portion of a street or alley adjacent to the proposed subdivision, the remainder of the street or alley to the prescribed width shall be platted within the proposed subdivision.
(5) (a) The widths of streets shall conform to the widths specified in this chapter according to type of use. The minimum right-of-way widths of arterial and collector streets being 80 feet. The paved width for arterial and collector streets shall be determined by the City Engineer. Residential streets, which have a paved width of 31 feet or more approved by the Council, shall have a minimum right-of-way width of 50 feet. Any exceptions will need the approval from the Planning Commission and the City Council. Cul-de-sacs shall have a minimum right-of-way radius of 60 feet and shall be paved a minimum of 50 feet measured back of curb to center point of the turnaround.
(b) In areas zoned exclusively for single-family residences, cul-de-sacs not more than 1,000 feet in length and loop streets or circle drives not more than 1,000 feet in length may be paved a minimum of 31 feet in width, measured back of the curb to back of curb, if there is adequate off-street parking and the Council approves. All measurements shall be made along the centerline of the cul-de-sac, circle drive or loop street right-of-way. Length shall be determined by measuring from the centerline of an intersecting street to the centerline of the intersecting street for a loop street or circle drive, or from the centerline of the intersecting street to the center of the cul-de-sac.
(6) Alleys shall be discouraged in residential districts, but should be included in commercial and industrial areas where needed for loading, unloading or access purposes. Where platted, alley right-of-way widths shall be at least 25 feet.
(7) The centerlines of streets should intersect as nearly at right angles as is possible.
(8) Where an alley intersects a street property line, corners shall be rounded by arcs of at least 20 feet radii or by chords of the arcs.
(9) At intersections of streets, the property line corners shall be rounded by arcs with radii of not less than 15 feet, or by chords of the arcs. Back of curb radii shall be not less than 25 feet.
(10) If the smaller angle of intersection of two streets is less than 60 degrees, the radius of the arc at the intersection of property lines and back of curb shall be increased as deemed advisable by the Commission.
(11) Intersections of more than two streets at one point shall be avoided.
(12) Whenever the proposed subdivision contains or is adjacent to a highway designated as a controlled access highway by the appropriate highway authorities, provisions shall be made for a marginal access street, a parallel street at a distance acceptable for the appropriate use of the land between the highway and the parallel street, to the limiting of access, where possible and practical, to the street by restrictive covenant. Whenever the proposed subdivision contains or is adjacent to a street designated as a secondary street or as a primary street in the street plan, provisions may be made of limiting access, where possible and practical, to the street by restrictive covenant.
(13) The minimum length of vertical curves, expressed in feet, to permit adequate stopping sight distance on all streets shall be established along the centerline of the streets as follows:
(14) Curvature measured along the centerline shall have a minimum radius as follows:
(15) An option is open to use superelevation with reduced curve radii on curves, subject to the review and approval of the City Engineer.
(16) Between reversed curves on arterial streets a tangent of not less than 200 feet shall be provided and on feeder and residential streets a tangent shall be not less than 100 feet.
(17) Maximum or minimum grades.
(a) Arterial streets, not greater than 4%;
(b) Feeder and residential streets, not greater than 8%;
(c) The minimum grade of any street gutter and alley inverted crown shall not be less than 0.5%, unless a lesser grade is specifically authorized in writing by the City Engineer;
(d) In approaching intersections, there shall be a suitable leveling of the street at the grade, generally not exceeding 4% and for a distance of generally not less than 100 feet from the nearest line of the intersecting street. The grade within the intersection shall be as level as possible permitting proper drainage;
(18) The design of the intersection shall be such that a clear sight distance will be maintained in accordance with the Iowa Department of Transportation Design Manual, Chapter 6A-4, Horizontal Sight Distance at Intersections.
(19) Street names. Streets that are obviously in alignment with others already existing and named shall bear the name of existing streets. The names of new streets shall be shown on the final plat and the names shall not duplicate or sound similar to existing street names. The City Engineer shall determine house numbers.
(20) Roundabouts may be used at intersections to control traffic as well as to calm traffic. Roundabouts should be considered during design of any new street intersection as part of a subdivision. If expected future traffic loads are large enough to warrant a roundabout, it may be required as part of the subdivision improvements. Operational and safety characteristics of roundabouts should be compared with those of signalized and un-signalized intersections on all projects and be used if deemed appropriate. Proposed designs should be based on Federal Highway Administration Publication Number FHWA-RD-00-067, Roundabouts: An Informational Guide. Minimum dimensions for a roundabout are as follows:
(a) One hundred-foot inscribed circle diameter;
(b) Sixteen-foot wide entry lanes;
(c) Twenty-foot circulatory lane width.
(H) Blocks.
(1) Blocks shall not be less than 500 feet or longer than 1,000 feet in length.
(2) Blocks shall be of sufficient width to permit two tiers of lots of appropriate depth, except where and interior street parallels a limited access highway or arterial street.
(I) Lots.
(1) All lots shall abut on a street or place.
(2) Side lines of lots shall be at approximately right angles to straight streets and on radial lines on curved streets. Some variation from this rule is permissible, but pointed or very irregular lots should be avoided.
(3) Double frontage lots should not be platted, except that where desired along arterial, limited access highways or streets, lots may face on an interior street and back on the thoroughfares. In that event a planting strip is used for a screen, at least 20 feet in width shall be provided along the back of the lot.
(4) Prior to the approval of a preliminary plat of an area where a public sanitary sewer outlet and/or a public water supply are not available, the Commission shall receive certification from a professional engineer, registered in accordance with the applicable provisions of the Iowa Code, that lot size, soil conditions, area and topography within the subdivision are suitable for the installation of private or quasi-public sewage treatment and disposal systems and/or water well systems in accordance with the applicable state and county Board of Health laws, rules and regulations governing the installation of the systems. The certification shall provide proof that the county Board of Health has reviewed and approved the methods and determination of the certification. Where a public sanitary sewer outlet and a public water supply are available to the entire subdivision, the widths and areas of lots shall be not less than provided in the zoning regulations of the city for the district in which the subdivision is located.
(5) The depth-to-width ratio of the usable area of a lot shall be at a maximum of three to one.
(6) Corner residential lots shall be wider than normal in order to permit appropriate setbacks from both streets.
(7) No strip of land shall be reserved by the subdivider unless the tract is of sufficient size and shape to be of some practical use or service as determined by the Commission and Council.
(8) The land contour of all lots shall contain a building site with an elevation of sufficient height to permit construction of the lowest habitable floor of a building one foot above a 100-year flood level.
(J) Easements.
(1) Easements for utilities. Where alleys are not provided, easements for utilities shall be provided. The easements shall have minimum widths of 15 feet, and where located along lot lines, one-half the width shall be taken from each. Before determining the location of easements, the plan shall be approved by the local public utility companies to assure the proper placement of the easements for the installation of the services.
(2) Easements along streams and watercourses. Whenever any stream or surface watercourse is located in an area that is being subdivided, the subdivider shall, at his or her own expense, make adequate provisions for the proper drainage of surface water and shall also provide and dedicate to the city an easement along the streams and watercourses meeting the approval of the Plan Commission.
(K) Building setback lines. Building setback lines shall be established as required by the zoning regulations of the city.
(L) Land for public purposes. Where sites for parks, schools, playgrounds or other public uses are located within the subdivision area as shown on the comprehensive plan, or where the sites appear to be desirable, the Commission may request their dedication for the purposes, or their reservation for a period of one year following the date of the approval of the plat.
(M) Areas subject to 100-year flood frequency. All subdivisions located or partially located below the 100-year flood frequency elevation which contain three acres or two lots, whichever is less, shall note the location of the 100-year flood frequency area and the elevation.
(N) Watercourses. Flood-carrying capacity within an altered or relocated portion of any watercourses shall be maintained. The applicant will notify adjacent communities and the state coordinating office prior to any alteration or relocation of a watercourse.
(O) Maintenance of improvements outside corporate limits. Where a subdivision outside the corporate limits contains sewers, sewage treatment plants, water supply systems, park areas, street trees or other physical facilities necessary or desirable for the welfare of the area and which are of common use or benefit and which the city does not desire to or cannot maintain, provision shall be made by trust agreements, made a part of the deed restrictions acceptable to the Council for the proper and continuous maintenance and supervision of the facilities by the lot owners in the subdivision.
(Ord. 2389, passed 10-28-2008; Ord. 2489, passed 3-26-2013; Ord. 2536, passed 4-12-2016) Penalty, see § 10.99