In order to control potential storm water damage and sediment pollution of water resources, wetlands, riparian areas, other natural areas, and public and private lands, the owner of each development area shall be responsible for developing a comprehensive Storm Water Management and Erosion and Sediment Control Plan. This plan will address storm water management (volume and peak rate of runoff), soil erosion, sediment and other wastes control. Such plan also must contain a description of controls appropriate for each construction operation covered by this Chapter; and the operator must implement the planned controls in a timely manner. The plans and BMPs used to satisfy the conditions of this Chapter shall meet the standards and specifications in the current edition of the Ohio "Rain Water and Land Development" manual issued and made available by the Ohio Department of Natural Resources, or standards of the Ohio EPA, whichever are most stringent. The plans must make use of the practices that preserve the existing natural condition to the maximum extent practicable. The Plan shall identify the subcontractors engaged in activities that could impact storm water runoff. The Plan shall contain signatures from all of the identified subcontractors indicating that they have been informed and understand their roles and responsibilities in complying with the Storm Water Management and Erosion and Sediment Control Plan.
(a) Development Sites ½ (One-half) Acre In Size or Larger. All developments that have a common plan of development or sale equal to or larger than one-half (½) acre in size of disturbed area are subject to this chapter and shall follow all of the requirements set forth in this chapter.
(1) Description of the plan of construction. The following information shall be included in the Storm Water Management and Erosion and Sediment Control Plan and submitted to the City prior to final Planning Commission approval:
A. Site Description:
1. A description of the prior land uses of the site.
2. A description of the nature and type of construction activity (for example, low density residential, shopping mall, highway, etc.).
3. A description of the total area of the site and the area of the site that is expected to be disturbed (namely, grubbing, clearing, excavating, filling or grading, including off-site borrow, fill or spoil areas and off-site utility installation areas).
4. An estimate of the impervious area and percent of imperviousness created by the construction activity.
5. The types of soils within, or affected by, the development area, and the location of all highly erodible or unstable soils as determined by the most current edition of the soil survey of the County, by the Natural Resources Conservation Service (NRCS).
6. An onsite, detailed soils engineering report if required by the City Engineer.
7. The name and/or location of the immediate receiving stream or surface water(s) and the first subsequent named receiving water and the major river watersheds in which it is located.
B. A vicinity sketch locating:
1. The larger common plan of development or sale;
2. The development area;
3. All pertinent surrounding natural features within 200 feet of the development site including, but not limited to:
a. Water resources such as wetlands, springs, lakes, ponds, rivers and streams (including intermittent streams with a defined bed and bank);
b. Conservation easements;
c. Other sensitive natural resources;
d. The sensitive areas receiving runoff from the development.
4. All off-site borrow or spoil areas;
5. All off-site utility installation areas that are related to the planned project.
C. The existing and proposed topography shown in the appropriate contour intervals as approved by the City Engineer (generally one-foot contours are used).
D. The location and description of existing and proposed drainage patterns and facilities, including any allied drainage facilities beyond the development area and the larger common plan of development or sale.
E. Existing and proposed watershed boundary lines, direction of flow and watershed acreage.
F. The person or entity responsible for continued maintenance of all vegetative and/or mechanical BMPs for both the construction and post-construction phases of the development.
G. Long-term maintenance requirements and schedules of all BMPs for both the construction and post-construction phases of the development will be provided as a stand alone document to the Post Construction operator and the City of Strongsville.
H. This plan will identify the person or entity that will serve as the Post-Construction operator who will be financially responsible for maintaining the perpetual inspection and maintenance of permanent storm water conveyance and storage structures and other conservation practices.
I. Maintenance plans must ensure that pollutants collected within structural Post-Construction practices be disposed of in accordance with local, state, and federal regulations.
J. Long-term maintenance inspection schedules and method of implementation.
K. The method of ensuring that funding will be available to conduct the long-term maintenance and inspections of all permanent storm water, soil erosion and sediment control, and water quality practices.
L. The location of any existing or planned riparian and/or wetland setback areas on the property.
M. The plan must clearly describe, for each major construction activity, the appropriate BMPs and the general timing (or sequence) during the construction process of when the measures will be implemented; and, who (which contractor) will be responsible for implementation (for example, Contractor A will clear, grub and install perimeter controls and Contractor B will maintain perimeter controls until final stabilization; Contractor C will conduct and document the scheduled inspections.)
N. Location and description of any storm water discharges associated with dedicated asphalt and concrete plants covered by this regulation and the Best Management Practices to address pollutants in these storm water discharges.
(2) Storm Water Management and Erosion and Sediment Control Plan. The Storm Water Management and Erosion and Sediment Control Plan shall include, at a minimum, the following information:
A. The Storm Water Management and Erosion and Sediment Control Plan shall include a map showing the location of:
1. The limits of earth disturbing activity including excavations, filling, grading or clearing.
2. Drainage patterns during major phases of construction.
3. The location of each proposed soil erosion and sediment control BMP, including:
a. Permanent soil erosion control practices to be left in place after construction operations have been completed (for example, level spreaders, permanent erosion control matting, gabions, rock lined channels, etc.),
b. Areas likely to require temporary stabilization during the course of site development,
c. Designated construction entrances where vehicles will access the construction site,
d. In-stream activities including stream crossings,
e. Areas designated for the storage or disposal of solid, sanitary and toxic wastes,
f. Temporary dumpsters,
g. Cement truck washout,
h. Fuel tanks,
i. BMPs that divert runoff away from disturbed areas and steep slopes where practicable, including rock check dams, pipe slope drains, diversions to direct flow away from exposed soils, and protective grading practices,
j. Sediment settling ponds drawn to scale.
4. Existing and proposed locations of buildings, roads, parking facilities and utilities.
5. Boundaries of wetlands and stream channels the owner intends to fill or relocate for which the owner is seeking approval from the U.S. Army Corps of Engineers and/or Ohio EPA.
B. The Storm Water Management and Erosion and Sediment Control Plan shall include a list of soil erosion and sediment control BMPs being used and the standards and specifications, including detailed drawings, for each BMP. This list shall include:
1. Methods of controlling the flow of runoff from disturbed areas so as to prevent or minimize erosion.
2. Identification of the Structural Practices to be used to control erosion and trap sediment from a site remaining disturbed for more than 14 days. A description shall be included of how each selected control will store runoff so as to let sediments settle out and/or divert flows away from exposed soils or act to limit runoff from exposed areas.
3. Identification for each Structural Practice of its size, detail drawings, maintenance requirements and design calculations.
4. The type and amount of plant seed, live plants, fertilizer, agricultural ground limestone and mulch to be used. Specification of soil testing requirements for fertility and lime requirements will be included. Specification for the use of perennial grass seed will also be included.
5. Settling ponds will be identified with basic dimensions and the calculations for size and volume.
6. Detailed drawings and installation requirements of all other structural control BMPs.
7. Any other soil erosion and sediment control related BMPs and items that are required by the City Engineer.
8. For developments where the overall plan does not call for centralized sediment control capable of controlling multiple individual lots, a detailed drawing of a project specific typical individual lot showing standard individual lot soil erosion and sediment control practices and the sequence and timing of BMP installation for the individual lots shall be provided. This does not remove or eliminate the responsibility to designate and install specific soil erosion and sediment control practices for the storm water discharges.
C. The Storm Water Management and Erosion and Sediment Control Plan shall include the scheduling, phasing, and coordination of construction operations and erosion and sediment control BMPs, including vegetative plantings and mulch.
(3) The Storm Water Management and Erosion and Sediment Control Plan shall include a description of the Storm Water Management (SWM) practices to be used on the site. The SWM element of the Plan shall include, at a minimum, the following:
A. A map showing the location, drawn to scale, of permanent SWM conveyance, detention and retention structures, other SWM control structures and the SWM easements.
B. A general description of the SWM strategy proposed to meet this chapter.
C. Hydraulic and hydrologic calculations for all permanent SWM conveyance, detention and retention structures, and other SWM control structures.
1. The storm water conveyance system calculations shall establish the adequacy of the storm water conveyance system to carry the design frequency storm. The flow route and drainage way necessary to convey the 100-year storm (emergency flow way) through the development shall be shown. The storm water conveyance system shall be designed per the requirements set forth in the latest edition of "The Uniform Standards for Sewerage Improvements," and all applicable, standards, regulations, ordinances, and policies, of the City of Strongsville. Storm water management detention and retention structures shall be designed in accordance with Section 1058.06.
2. The hydraulic and hydrologic calculations shall establish the adequacy of the conveyance system to receive and convey storm water from the up-stream property.
3. The hydraulic and hydrologic calculations shall establish the adequacy of the downstream drainage facilities to receive and convey storm water exiting the proposed development.
4. Submittals for review shall include but not be limited to:
a. A soils map of appropriate scale showing; contours at 2' intervals, soils types, ground cover and woodlands; the total drainage area tributary to the project, both before and after the proposed development, legend noting the soils area in acres by soils group, copy of the U.S. Department of Agriculture SCS Soil Survey of Cuyahoga County, latest addition, showing the entire drainage area.
b. Drainage area map of appropriate scale showing: contours at 2' intervals, all existing drainage facilities, all natural waterways, all proposed drainage facilities, emergency flow way.
c. Type II rainfall distribution and City of Strongsville rainfall data.
d. Runoff curve summary showing pre and post development conditions.
e. Runoff calculations.
f. Travel time and time of concentration calculations.
g. Calculations on peak discharge and discharge volume.
h. Pre and post development hydrographs.
i. Storage volume requirements.
j. Routing through proposed drainage facility using storage indication method.
k. Soil Conservation District Technical Release No. 55 or other method approved by the City Engineer must be utilized to produce the above.
D. Any other SWM related items required by the City Engineer.
(Ord. 2022-051. Passed 3-21-22.)