In order to control 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 Construction Site Conservation Plan. This plan will address storm water management (volume and peak rate of runoff), soil erosion, sediment and other wastes control. This plan must contain a description of controls appropriate for each construction operation covered by these regulations, and the operator must implement the planned controls in a timely manner. The plan and BMPs used to satisfy the conditions of these regulations shall meet the standards and specifications in the current edition of the Ohio Rain Water and Land Development manual. The plan 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 Construction Site Conservation 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 Construction Site Conservation Plan.
(a) Development Sites Under One (1) Acre in Size: Individual development sites that are larger than 8,000 square feet and smaller than one (1) acre (43,560 square feet) in total size of disturbed area, can submit abbreviated soil erosion and sediment control plans with the topography plan for the requested permit(s). The abbreviated plan must cover the following items, in addition to any other items from this chapter that are required by the City Engineer.
(1) Storm Water Issues: A statement as to how the increased storm water runoff that will be caused by the planned development project will be handled. The statement must identify the Best Management Practices (BMP'S) the new construction project will include in order to address storm water runoff.
(2) Redevelopment: Owners of development sites that were created by demolishing an older existing structure can request, in writing, that the City Engineer exempt them from the storm water issues if the total soil surface area being made impermeable is the same or less than the total soil surface area that was impermeable due to the structure(s) being torn down and removed. For a previously developed area, one or a combination of the following two conditions shall be met; (1) a twenty percent (20%) net reduction of the site's volumetric runoff coefficient through impervious area reduction with soil restoration or replacing impervious roof are with green roof area, or (2) treatment of twenty percent (20%) of the WQv (Water Quality Volume) for the previously developed area using a practice meeting table 4a/4b (1315.12(e)) requirements.
Where there is a combination of redeveloped areas and new development, a weighted approached shall be used with the following equation:
WQv = P * A * [(Rv1*0.2) + (Rv2 - Rv1)] / 12 (Equation 3)
where
P = 0.90 inches
A = area draining into the BMP in acres
Rv1 = volumetric runoff coefficient for existing conditions (current site impervious area)
Rv2 = volumetric runoff coefficient for proposed conditions (post- construction site impervious area)
Post-construction practices shall be located to treat impervious areas most likely to generate the highest pollutant load, such as parking lots or roadways, rather than areas predicted to be cleaner such as rooftops.
(3) Riparian and Wetland Setbacks: All riparian and wetland setback areas will be identified in the plan and in the field before construction starts.
(4) Soil Erosion and Sediment Issues: A sketch of the entire development site must be submitted that identifies the location of:
A. All existing and planned impervious areas, storm water inlets, drainage swales, wetlands, streams, conservation easements and other natural features to be saved and protected on the property.
B. All existing and planned temporary and permanent conservation practices for the site. Residential lots shall include at a minimum the following:
1. Soil erosion and sediment control BMPs, and;
2. Construction Entrance, and;
3. Temporary Grass Seeding with two (2) tons per acre of straw mulch, and;
4. Storm Drain Inlet Protection around every storm yard inlet on the site or accepting drainage from the site, and;
5. Silt Fence protection for any stream located on or close to the site and lacking an adequate vegetative buffer, and;
6. Silt Fence to prevent sediment discharge into street storm sewer inlets where no centralized sediment control exists for the drainage area that includes the lot, and;
7. Construction fence to protect any conservation easements, riparian setbacks and wetland setbacks from encroachment by construction activities.
(b) Development Sites One (1) Acre In Size or Larger: All developments that have a larger common plan of development or sale equal to or larger than one (1) acre in size of disturbed area are subject to this ordinance and shall follow all of the requirements set forth in this ordinance.
(1) Description of the Plan of Construction: The following information shall be included in the Construction Site Conservation Plan:
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 (e.g., 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 (i.e., 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 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 Community 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 Community 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.
H. Long-term maintenance inspection schedules.
I. The person or entity financially responsible for conducting the inspections of, and the maintenance of, permanent storm water conveyance and storage structures and all other conservation practices.
J. 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.
K. The location of any existing or planned riparian and/or wetland setback areas on the property.
L. 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 (e.g., 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.)
M. 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) Construction Site Conservation Plan Elements: the Construction Site Conservation Plan shall include, at a minimum, the following information:
A. The Construction Site Conservation 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 (e.g. 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. 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 US Army Corps of Engineers and/or Ohio EPA.
B. The Construction Site Conservation Plan shall include a list of soil erosion and sediment control BMPs being used and the standards and specifications, including detailed drawings, for each BMPs. 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 fourteen (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 Community Engineer.
8. For developments where the overall plan does not call for centralized sediment control capable of controlling multiple individual lots, a detail 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. 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 Construction Site Conservation Plan shall include the scheduling, phasing, and coordination of construction operations and erosion and sediment control BMPs, including vegetative plantings and mulch.
(3) The Construction Site Conservation 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. Design calculations for all permanent SWM conveyance, detention and retention structures, and other SWM control structures.
D. A minimum of one green infrastructure/infiltration stormwater control measure (SCM) to be included on the Construction Site Conservation Plan or any combination of green infrastructure and infiltration practices to be installed on site when feasible. This includes, but is not limited to, bioretention areas/cells, infiltration basins, infiltration trenches, and permeable pavement. Any site exemption to this requirement is to be determined by the Community Engineer pending a review of valid site restrictions provided by the developer. For permeability requirements, refer to Section 1315.12(e) Table 4b - Infiltration Post-Construction Practices with Maximum Drain Times or 1317.09 Table 2.
E. For redevelopment projects/previously developed area requirements, refer to Section 1315.08(a)(2) of this chapter
F. Any other SWM related items required by the Community Engineer.
(Ord. 2022-17. Passed 3-22-22.)