(a) Requirements for Subdivisions. Plans, profiles and supporting documentation to verify conformance with this chapter shall be submitted along with the usual plan submissions required in Chapter 1161 of the Planning and Zoning Code as follows:
(1) Preliminary plans. In addition to the requirements of Chapter 1161, a plan showing the total area contributing runoff to the subdivision or project area being considered shall be submitted with the preliminary plans. This plan shall contain, but is not limited to, the following information:
A. A contour plan showing the outline of all areas outside the project area that contribute runoff to it;
B. Estimated runoff (Q) before and after development for terminal points along natural streams, proposed open channels and other strategic points, such as existing storm sewers or culverts;
C. The location of proposed detention/retention areas; and
D. Any other information required by the City Engineer to clarify intent.
(2) Final plans. In addition to the requirements of Chapter 1161 of the Planning and Zoning Code, the final plan for the project area shall contain, but is not limited to, the following information:
A. Diameter, length, slope, type of pipe (ODOT designation for concrete pipe), and class (if other than Class II), of all storm sewers, culverts and subsurface drainage;
B. Invert elevations on profiles of all pipes at terminal points, such as manholes, inlets and catch basins and head walls;
C. Top of grate elevations of manholes and grate flow lines of catch basins and inlets located outside the public right of way. This information shall be submitted for structures within the right of way when required by the City Engineer.
D. The type of catch basin, inlet and manhole:
E. The head wall type;
F. Actual existing and proposed cross sections of open channels showing the width of the bottom, the depth of water, erosion control measures and limits and side slopes at each point of design, along with a profile indicating the longitudinal slope and bottom elevation at the terminal points of design;
G. High and low points indicating the direction of runoff flow along the profile of a roadway;
H. Structural details and design data for detention/retention facilities;
I. Details of construction for all structures not included in the City standard construction drawings, this chapter or other referenced standards;
J. Easements;
K. Other requirements of this chapter; and
L. Any other information required by the City Engineer to clarify intent or design features.
(3) Drainage and grading plans. In addition to the final plan, a drainage and grading plan shall be submitted. This plan may be the final plan required above or a similar plan at a scale of one inch equals 100 feet or larger, showing at least the following additional information:
A. Contours indicating the existing and final grade at vertical increments of no more than two feet;
B. Discharge (Q), coefficient of runoff (c) and drainage area (A), along with the outline of the drainage area for each inlet, catch basin, culvert and open channel point of design, and other locations designated by the City Engineer. Drainage areas that lie partially outside the limits of the drainage and grading plan may be delineated on any contour map acceptable to the City Engineer.
C. Discharge (Q) before and after development, in accordance with the Stormwater Management Design Manual requirements, at strategic points within and at the extremities of the project area;
D. Delineation of the boundaries and contour elevation, along with the track, of the major drainage system through downstream areas to an adequate outlet, though the outlet may be outside the project area;
E. Delineation of the horizontal limits of ponding areas at low points (sags) in the street profile and low points outside the street right of way, including, but not limited to, culverts, headwaters, natural stream water surfaces and sump-type inlets.
F. High and low water horizontal limits and contour elevations of detention/retention/sedimentation facilities, along with water surface and control weir elevations, outlet structures, etc.;
G. Areas outside the project area susceptible to sediment deposits or to erosion caused by accelerated runoff;
H. The location of soils that may be limited for the proposed use;
I. All requirements of this chapter;
J. The location of all public easements, both existing and those to be dedicated; and
K. Any other information required by the City Engineer to clarify intent or specify design requirements or design features.
(4) Supporting data. All data and design information used for the design of drainage facilities and for determining downstream flood information shall be submitted with the drainage and grading plan. To facilitate review and to avoid confusion, legends, descriptions and structure numbering, used on design forms or other calculations, shall be identical to those used on the final plans and the drainage and grading plan. This data shall include, but are not limited to:
A. Weighted runoff coefficient calculations for each contributing area;
B. Pavement drainage calculations;
C. Storm sewer computations;
D. Culvert design computations;
E. Open channel computations;
F. Detention/retention facilities computations;
G. Major drainage system computations, unless specifically not required by the City Engineer; and
H. Any other information required by the City Engineer to clarify intent or design features.
(5) As-built plans. Amended final plans specifying the locations, dimensions, elevations and capacities of all facilities, as constructed, shall be submitted to the City on completion of construction of the project. These shall include all required design features except those waived by the City Engineer.
(b) Submission Requirements for Land Developments Other Than Subdivisions. Submission requirements for land developments other than subdivisions shall be the same as the requirements for subdivisions, but may be altered by the City Engineer for specific project areas.
(c) Covenants Describing Maintenance Responsibilities. Covenants describing maintenance responsibilities pursuant to Section 919.07 shall be detailed on the plat drawing of the subdivision.
(Ord. A-1947. Passed 3-14-94.)