(A) A preliminary plat shall be based on a legal description of the property as shown by the land records in the County Recorder’s office. A preliminary plat shall meet the design standards set forth in these regulations.
(B) Plats shall be drawn to a scale of not less than one inch equals 100 feet (1" = 100'), on a sheet size of 24 inches by 36 inches in size; shall list a professional land surveyor licensed in the state; and shall illustrate the following information:
(1) Name of subdivision;
(2) Name and addresses of owner, developer, engineer and licensed professional land surveyor;
(3) Date of preparation, scale with a graphical bar scale and north arrow;
(4) A vicinity map shall be presented accompanying or included on the preliminary plat showing the geographic relationship to the proposed subdivision to the surrounding area. Features to be noted include major street patterns, land uses, public areas and others affecting the project; vicinity maps shall be prepared at a scale of no smaller than one inch equals 1,000 feet;
(5) Title including the language “preliminary plat” and complete official legal description of the boundary of the property to be subdivided including acreage;
(6) If phasing of subdivision is proposed, note and indicate on plat;
(7) Location of section and quarter-section lines in relation to plat. Location of existing monuments and complete description of preliminary control points to which all dimensions, angles, bearings and similar data on the plat shall refer;
(8) Accurate bearings and distances of subdivision boundary lines, blocks, lot lines and right- of-way lines. Each lot shall be identified by a number and the area in square feet of each lot shall be designated. Dimensions of streets, alleys, easements and other proposed dedicated areas shall conform to the current Zoning Ordinance or the developer’s proposed zoning plan;
(9) Where applicable, boundaries of the (FP) flood plain overlay zone;
(10) All lands and/or subdivisions shall be shown for a distance of 200 feet from all sides of land in question illustrating location, names and width of streets, alleys, roads, highways, railroad right-of- ways, driveways, intersections, curb cut, buildings, utility rights-of-way or easements, section lines, names of adjoining subdivisions and name of the owners of adjoining parcels and the like;
(11) Proposed street names in conformance with the city street grid map on file with the Planning and Zoning Department;
(12) The following notes shall be included on the plat:
(a) Central Iowa is a region underlain by clayey soils which allow for a shallow perched groundwater table. During wet periods of weather, the groundwater level may be less than six feet below the surface. This can result in groundwater seeping and flowing into below grade living and storage areas that are not equipped with sump pumps or other dewatering mechanisms.
(b) Structures, buildings and utilities shall be designed and constructed to prevent groundwater and storm runoff from entering into the sanitary sewer system.
(13) Other data including but not necessarily limited to the following:
(a) A tabulation of total acreage of the subdivision, number of lots for each zoning classifications and acreages designated to other uses;
(b) Delineation and acreage of areas to be dedicated or reserved for public use such as schools, parks, playgrounds, churches, open space and public streets;
(c) Building setback lines or restrictions with dimensions;
(d) Drainage channels, wooded areas and other significant natural features. Designate areas to be preserved;
(14) Preliminary plat engineering plans for Planning and Zoning Commission action shall be designed with adequate water mains, fire hydrants, sanitary sewer lines and stormwater detention per the criteria in the most recent version of the Statewide Urban Design and Specifications (SUDAS) and the city Supplemental Specifications to SUDAS; and in accordance with the ordinances and regulations of the city, so as to protect the public health and welfare, and so not to overload any existing public utility. The preliminary plat engineering plans shall include but not necessarily limited to the following:
(a) Cover sheet including project name, legend, general notes for the project, sheet index,
list of contact information for owner, engineer, developer and utility companies, and project benchmark information including vertical datum, basis of bearings and horizontal control;
(b) Existing conditions plan showing existing topography with contour lines at intervals
of two feet maximum and names and widths of existing streets, alleys, highways, railroad right-of-ways, driveways and curb cuts located within 200 feet of the proposed subdivision boundary. The plan shall also show all existing buildings, sanitary sewer, water mains, storm sewer, culverts or other underground structures on and within 200 feet of the proposed subdivision boundary. If water mains and sewers are not on or adjacent to the tract, direction and distance to nearest ones shall be shown, including preliminary invert elevations of sewers, based on U.S.G.S. datum;
(c) Master layout/phasing plan showing the alignment and names of all proposed roadways and sidewalks and phase lines, if applicable. Horizontal curve information of street centerline shall include the radius, length of curve, central or deflection angle. stationing of point of curvature and point of tangent;
(d) Grading plan showing existing and proposed contour lines for the proposed subdivision with maximum intervals of two feet and the centerline grade for proposed streets shown in percentage of grade. Street flowline grade shall be shown for all horizontal curves. The vertical datum for elevations and contours shall be based on U.S.G.S. datum;
(e) Drainage plan showing disturbed areas, proposed drainage patterns, boundaries of the (FP) flood plain overlay zone (where applicable), and stormwater detention facilities. In addition to the drainage plan, a drainage report shall be prepared with all pertinent preliminary stormwater runoff, conveyance and detention calculations. The drainage plan and drainage report shall be prepared by an engineer;
(f) Master utility plan showing the location, size and type of material of proposed utilities and facilities, including water, storm sewer and sanitary sewer. Location of existing and proposed fire hydrants, existing and proposed easements, all existing utilities both on and within 100 feet of the area to be platted, alignment of all dry utilities including gas, electric, telecommunications, and cable television, and utility extensions necessary to properly develop subdivision and adjoining area shall be shown;
(g) Signage, striping and lighting plan showing all signs, street lights, and pavement markings within the proposed subdivision. A sign table shall be included listing all signs, their MUTCD designation and the number required;
(h) Landscape plan showing existing and proposed landscaping, including name and size
of plant material and sight distance triangles at all applicable locations. The landscape plan shall show all utilities, easements and stormwater detention ponds;
(i) Geotechnical engineering exploration and report will be required to determine suitability of soils and groundwater levels for the proposed construction of pavements and buildings. The report shall provide a pavement thickness design; and
(j) Traffic study, unless waived by the Public Works Director.
(15) Preliminary plat construction plans for City Council action shall be designed with adequate water mains, fire hydrants, sanitary sewer lines and stormwater detention per the criteria in the most recent version of the Statewide Urban Design and Specifications (SUDAS) and the city Supplemental Specifications to SUDAS; and in accordance with the ordinances and regulations of the city, so as to protect the public health and welfare, and so not to overload any existing public utility. The preliminary plat construction plans shall include but not necessarily limited to the following:
(a) Cover sheet existing conditions plan, master layout/phasing plan, signage striping and lighting plan, and landscape plan as described in subsection (14) above;
(b) Grading plan showing existing and proposed contours for the proposed subdivision with maximum intervals of two feet and the center line grade for proposed streets shown in percentage of grade. Street flowline grade shall be shown for all horizontal curves and at all intersections. The vertical datum for bench mark elevations and contours shall be based on U.S.G.S. datum;
(c) Drainage and erosion control plan showing disturbed areas, temporary and permanent erosion control measures, proposed drainage patterns, boundaries of the (FP) flood plain overlay zone (where applicable) and stormwater detention facilities. In addition to the drainage erosion control plan, a drainage report shall be prepared with all pertinent stormwater runoff, conveyance and detention calculations. The drainage and erosion control plan and drainage report shall be prepared by an engineer;
(d) Master utility plan showing the location, size and type of material of proposed utilities and facilities, including water, storm sewer and sanitary sewer. Location of existing and proposed fire hydrants, existing and proposed easements, all existing utilities both on and within 100 feet of the area to be platted, alignment of all dry utilities including gas, electric, telecommunications, and cable television, conduits for dry utility sleeves beneath proposed roadways with size and use of conduit labeled, and utility extensions necessary to properly develop subdivision and adjoining area shall be shown;
(e) Street plan and profiles showing proposed street improvements including curb/gutter, storm inlets, sidewalks, bike paths, alleys, cross pan widths, flowline slope along horizontal curves. Profiles shall be of the street centerline and show the existing and proposed grade of the street centerline. Vertical curve data shall include the beginning and ending grades, length of curve, stationing for point of vertical curvature, point of vertical intersection and point of vertical tangent. Intersections and cul-de-sacs shall include flowline spot elevations and flowline and cross slopes. If the plan is too cluttered, separate intersection details shall be provided. Proposed contours and utilities are typically not shown in the plan view;
(f) Utility plan and profiles of water mains, sanitary mains and storm sewer pipe. Separate sheets shall be provided for each utility. All existing and proposed utilities shall be shown in plan view including valves, fire hydrants, manholes, storm inlets and service lines. Profiles shall show existing and proposed grades, all crossings with other existing and proposed utilities, and vertical distance between outside of pipe to outside of pipe. The pipe size, class and length between fittings or manholes shall be labeled. The profiles for water shall denote the minimum and maximum final cover over the top of pipe. The profiles for sanitary and storm sewer shall include the pipe slope between manholes, manhole rim elevation and manhole invert elevations. All service lines shall be listed in a table with stationing and direction. Water main pressure calculations may be required; and
(g) Detail sheets showing construction details and specifications for all the proposed improvements, including but not limited to utilities, typical street cross sections, sidewalks and handicap curb ramps, pavement section, curb and gutter, and landscaping. Details shall conform to the Statewide Urban Design and Specifications (SUDAS) and the city Supplemental Specifications to SUDAS.
(Ord. 2217, passed 11-4-2013)