(A) Project sites that do not meet criteria. For project sites that do not meet the criteria for a small, residential development in § 53.024 of this subchapter, a project site owner must develop and submit a set of construction plans. Storm water quality measures included in the plan must achieve the minimum project site requirements specified in §§ 53.025 and 53.027 of this subchapter. The construction plans must include the following components, content, requirements and provisions as hereinafter provided.
(B) Construction plan. The construction plan must include the following 8 major components:
(1) Project narrative and supporting documents; see division (C)(1) below;
(2) Vicinity map; see division (C)(2) below;
(3) Existing project site layout; see division (C)(3) below;
(4) Final project site layout; see division (C)(4) below;
(5) Grading plan or land disturbing activity plan; see division (C)(5) below;
(6) Storm water drainage plan; see division (C)(6) below;
(7) Construction phase storm water pollution prevention plan; see division (C)(7) below; and
(8) Post-construction storm water pollution prevention plan; see division (C)(8) below.
(C) Components must have sub-components. Each of the 8 major components of the construction plan must consist of the following sub-components and their subdivisions of content:
(1) Project narrative and supporting documents, including the following information:
(a) An index indicating the location, in the construction plan, of all information required by this section;
(b) Description of the nature and purpose of the project;
(c) Legal description of the project site. The description must be to the nearest quarter section, township, and range, and include the civil township;
(d) Soil properties, characteristics, limitations, and hazards associated with the project site, and the measures that will be integrated into the project to overcome or minimize adverse soil conditions;
(e) General construction sequence of how the project site will be built, including phases of construction;
(f) Hydrologic unit code (14 digit) available from the United States Geologic Survey (USGS) or the office of the Storm Water Coordinator to indicate within which watershed or watersheds the project site lies;
(g) A plat or project site map showing lot numbers, lot boundaries, road layout and names. The plat must be legible and submitted on a sheet or sheets no larger than 24 inches by 36 inches and drawn at a maximum scale of 1 inch equals 100 feet for all phases or sections of the project. The Engineer or Storm Water Coordinator will determine the appropriateness of the size and scale of the plat or map; and
(h) Identification of any other state or federal water quality permits that are required for construction activities associated with the owner's project site.
(2) Vicinity map depicting the project site's location in relationship to recognizable local landmarks, cities, towns, major roads, and railways. The applicable portion of a USGS topographical quadrangle map, or county or municipal road map with the project site limits linked in will suffice.
(3) An existing project site layout that must include the following information:
(a) Location and name of all wetlands, lakes, streams, waterways, and drains on, or adjacent to, the project site;
(b) Location of all existing structures on the project site;
(c) One hundred year flood plains, floodway fringes, and floodways; (Note if none exists)
(d) Soil map of the predominant soil types, as determined by the USDA, NRCS Soil Survey, or equivalent publication, or as determined by a soil scientist. The soil map must include a soil legend;
(e) Identification and delineation of the pre-development vegetative cover such as grass, weeds, brush, and trees on the project site;
(f) Land use of all adjacent properties;
(g) Existing topography extending at a minimum of 50 feet beyond the property lines to adequately indicate drainage patterns on and off the project site. The contour intervals shall be drawn in accordance to the following criteria:
1. Average ground slope between 0 and 2% use 1-foot contour intervals;
2. Average ground slope between 2 and 10% use 2-foot contour intervals; and
3. Average ground slope greater than 10% use 5-foot contour intervals.
(h) The Town of Chandler Engineer or Storm Water Department Manger reserves the right to determine the appropriateness of the contour intervals and request additional spot elevations to adequately indicate drainage patterns on and off the project site.
(4) Final project site layout, including the following information:
(a) Location of all proposed site improvements including; roads, utilities, lot delineations and identification, proposed structures, and common areas;
(b) One hundred-year flood plains, floodway fringes, and floodways; (Note if none exists)
(c) Proposed final topography extending at a minimum of 50 feet beyond the property lines to adequately indicate drainage patterns on and off the project site. The contour intervals shall be drawn in accordance to the following criteria:
1. Average ground slope between 0 and 2% use 1-foot contour intervals;
2. Average ground slope between 2 and 10% use 2-foot contour intervals; and
3. Average ground slope greater than 10% use 5-foot contour intervals.
(d) The Town of Chandler Engineer or Storm Water Department Manager reserves the right to determine the appropriateness of the contour intervals and request additional spot elevations to adequately indicate drainage patterns on and off the project site.
(5) A grading plan, including the following information:
(a) Delineation of all proposed land disturbing activities, including off-site activities that will provide services to the project site;
(b) Location of all soil stockpiles and borrow areas;
(c) Information regarding any off-site borrow, stockpile, or disposal areas that are associated with the project site and under the control of the project site owner; and
(d) Existing and proposed topographic information per divisions (C)(3)(g) and (C)(4)(c) above.
(6) A drainage plan, including the following information:
(a) An estimate of the peak discharge, based on the 10-year storm event; of the project site for both pre-construction conditions and estimates of the peak discharge based on the 10-year, 25-year, and 50-year storm events of the project site for post construction conditions. The calculations to determine these discharges shall be included in the drainage plan;
(b) Location, size and dimensions of all components of the storm water drainage systems such as inlets, culverts, storm sewers, and conveyance channels;
(c) Locations where storm water potentially will be directly discharged into ground water, such as abandoned wells or sinkholes; (Note if none exists)
(d) Location of every specific point where storm water discharge will leave the project site;
(e) Name of all receiving waters. If a discharge is to a separate municipal storm sewer, identify the name of the municipal operator and the name of the ultimate receiving water; and
(f) Location, size, and dimensions of features such as permanent retention or detention facilities, including existing or manmade wetlands, used for the purpose of storm water management.
(a) Location, dimensions, detailed specifications, and construction details of all temporary and permanent storm water quality measures, ECMs, and BMPs;
(b) Temporary stabilization plans and sequence of implementation;
(c) Permanent stabilization plans and sequence of implementation;
(d) Final stabilization plans;
(e) All stabilization plans shall include the following:
1. Specification and application rates for soil amendments and seed mixtures;
2. The type and application rate for soil amendments and seed mixtures; and
3. Other applicable data as may be required by the Town of Chandler Engineer or Storm Water Department Manager.
(f) Construction sequence describing the relationship between implementation of storm water quality measures, ECMs, and BMPs, and the stages of construction activities;
(g) The project site owner's self-monitoring program including plan implementation and procedures;
(h) A description of potential pollutant sources associated with construction activities, which may reasonably be expected to add a significant amount of pollutants to storm water discharges; and
(i) Material handling and storage associated with construction activities that shall meet the spill prevention and spill response requirements in 327 I.A.C. 2-6.1.
(8) The post-construction Storm Water Pollution Prevention Plan (SWP3). The post-construction SWP3 must include the following information:
(a) A description of potential pollutant sources from the project site's proposed land use, which sources may reasonably be expected to add a significant amount of pollutants to storm water discharges from the post-construction project site;
(b) Location, dimensions, detailed specifications, and construction details of all post-construction storm water quality measures and BMPs adequate to address division (C)(7)(a) above;
(c) A description of control measures and BMPs that will be installed to control pollutants in storm water discharges that will occur after construction activities have been completed. The measures and practices include infiltration of storm water runoff; flow reduction by use of open vegetated swales and natural depressions; installation of filter strips, buffer strips, parking lot tree islands, and riparian zones; minimization of land disturbance and surface imperviousness; maximum of open space; and storm water retention and detention ponds;
(d) A sequence describing when each post-construction storm water quality measure and BMP will be installed;
(e) Storm water quality measures and BMPs that will remove or minimize pollution from storm water runoff within or from the project site;
(f) Storm water quality measures and BMPs that will be implemented to prevent or minimize adverse impacts to stream and riparian habitat;
(g) A narrative description of the maintenance guidelines for all post-construction storm water quality measures and BMPs to facilitate their proper long-term function; and
(h) A verifiable procedure, such as recorded plat notices and covenants, by which the narrative description of water quality measure and BMP maintenance guidelines will be made available to future parties who will assume responsibility for the operation and maintenance of the post-construction storm water quality measures and BMPs.
(D) Illustrations. Plan and profile sheets, project site layouts, plats, and vicinity maps, must be drawn to a standard engineering scale as indicated on each sheet, plat, or map, and be oriented north as indicated by a north arrow on each sheet, plat, or map. All dimensions must be accurately scaled, drawn, and labeled with dimensions given in feet and tenths of a foot.
(E) Revision of approved construction plans. The requirements for construction plan content enumerated in this section are qualified by the following statements:
(1) The Town of Chandler Engineer or Storm Water Department Manager may require, upon finding reasonable cause, the revision of a construction plan if it is determined that a modification or modifications are necessary to accomplish adequate control the quantity or quality of storm water runoff, in accordance with this subchapter or with applicable federal, state, and local rules, from a project site due to site conditions or project specification changes identified, effected, or extant during or after plan review an approval.
(2) If the Town of Chandler Engineer, Storm Water Management Board or Storm Water Department Manager requests a revised construction plan under this division, the project site owner must submit the revised plan to the appropriate entity or entities within 21 calendar days of a request for plan revision.
(Ord. 2006-6, passed - -; Am. Ord. 2008-10, passed 11-17-2008)