(a) Storm Water Management. The design and construction of Storm Water Management Facilities shall require the review and approval of the Village Road Commissioner and shall be in accordance with the Trumbull County Standard Drainage Criteria Manual. The Planning Commission shall consider but not be limited to consideration of the recommendation of the Road Commissioner on matters pertaining to storm water management.
The developer shall construct all necessary storm water management facilities including underground pipe, inlets, or catch basins, as determined by the Road Commissioner, to provide for the adequate disposal of subsurface and surface water, and maintenance of natural drainage courses. Storm water management facilities shall also include but not be limited to underground storage facilities, as necessary to control the amount and timing of storm water released to land within and adjacent to the proposed subdivision, to minimize off-site storm water runoff, increase on-site filtration, encourage natural filtration functions, preserve natural drainage systems, and minimize off-site discharge of pollutants to ground and surface water. In all cases, the developer shall provide for a storm water management system in a proposed subdivision to ensure that post- development storm water runoff rates do not exceed pre-development storm water runoff rates. Construction of storm water management facilities shall be in accordance with the Erosion and Sediment Control Plan as required in Section 1107.03
and shall follow the standards and specifications for soil erosion and sediment control as established in Rainwater and Land Development: Ohio’s Standards for Storm Water Management, Land Development and Urban Stream Protection, (Ohio Department of Natural Resources, Division of Soil and Water Conservation).
(b) Storm Water Management Plan. It is the intent of these Regulations to mitigate the detrimental effects of accelerated storm water runoff due to construction activity and development. Where a proposed subdivision involves the removal or disturbance of natural topsoil, trees, and/or vegetation, or where a proposed subdivision involves a change in the natural surface contour of land in the proposed subdivision, the developer shall prepare and submit a Storm Water Management Plan to the Road Commissioner for review and approval. The Storm Water Management Plan shall be included in the improvement plans for the proposed subdivision. The Storm Water Management Plan shall conform to the requirements of the Village Road Commissioner and the Trumbull County Standard Drainage Criteria Manual, and at a minimum include the following information:
(1) Identification. The Plan shall include sufficient contours and grading details to indicate proposed lot grading and drainage to ensure runoff will enter the drainage system as designed. Existing soils and surface water locations shall be identified, including springs, wetlands, streams, lakes, etc. on and within two hundred (200) feet of the proposed subdivision.
(2) Controls. The Plan shall indicate all storm water improvement and facilities which are used to control storm water runoff and shall address such issues as volume, timing, and rate of runoff. Inclusive of major items in the Plan design are: size, type, special features, typical sections, and easement widths - including charts, plans, and profiles. In no case shall storm water runoff be permitted to be released into a central sanitary sewage collection system.
(3) Maintenance. The Plan shall provide a description of maintenance procedures needed to assure continued performance of control practices, and shall be designed to minimize maintenance requirements. All control practices, whether temporary or permanent, shall be maintained and repaired, during construction and the maintenance guarantee period, by the developer, as determined to be necessary by the Road Commissioner, to assure continued performance of their intended function.
(4) Inspection. The Plan shall provide that all storm water management controls on the site are inspected after any storm event with greater than one-half (½) inch of rain in a twenty-four (24) hour period. The developer shall maintain and keep on site an inspection log, which shall note the name of inspector, date and time of inspection, area(s) requiring maintenance, description of actual maintenance performed, and date and time actual maintenance was performed.
In addition, the following data and support calculations shall be provided. All calculations and design specifications shall be prepared by a Professional Engineer registered in the State of Ohio.
A. Hydrologic Calculations.
1. Tributary drainage areas delineated on a map with contributing acreage shown.
2. Design flow.
3. Design year frequency.
4. Supporting calculations for the above, giving times of concentration, intensity, and runoff coefficients
B. Hydraulic Calculations.
1. Sufficient documentation to indicate the results of the investigation into the downstream drainage system’s ability to accept the anticipated runoff from the proposed development. The results will determine the maximum allowable release rate for the proposed development (not to be more than the ten year pre-development discharge) and in turn, the amount of storm water storage that will be required.
2. The plan and profile of all drainage ways shall be provided, superimposed upon which shall be the design energy and hydraulic grade lines.
3. The plan and profile of the entire storm sewer system shall be provided along with calculations supporting sizes and types of drainage improvements.
4. The plan and profile of all culverts (including driveway culverts) shall be provided along with calculations indicating culvert headwater and channel capacities (upstream and downstream). This information is required to insure against adverse affects resulting from excess overflow, erosion, and backwater within the proposed subdivision. Such calculations shall be substantiated by any additional information that is required to determine profile and cross- section of the upstream and downstream channel reaches under consideration.
(c) Drainage Systems.
(1) Central storm water collection system. Where a central storm water collection system exists within a reasonable distance of a proposed subdivision, the developer shall design and construct a system of mains, inlets, and other appurtenances as determined by the Road Commissioner to tie into said central storm water collection system, including a lateral connection for each proposed sublot or building site.
(2) Interim group storm water management. Where a central storm water collection system does not exist within a reasonable distance of a proposed subdivision, but where the proposed subdivision is located within a storm water management district established pursuant to applicable provisions of the Ohio Revised Code, the Planning Commission may do one of the following:
A. Refuse to permit the area to be developed if it finds a proposed use to be detrimental to the public health, safety, and/or welfare of the surrounding area, based upon receipt and consideration of a recommendation from the Village Engineer; or
B. Require the developer to design and construct a system of mains, inlets, and other appurtenances as determined to be necessary by the Village Engineer to tie into a central storm water collection system in the future, including a lateral connection for each proposed sublot or building site, and require the developer to design and construct, and provide for the operation and maintenance of an interim group storm water management facility to serve the proposed subdivision until it is tied into a central storm water collection system.
(3) Individual storm water management systems. Where a central storm water collection system does not exist within a reasonable distance of a proposed subdivision, and where the proposed subdivision is not located within a storm water management district, the developer may propose individual storm water management systems to serve the proposed subdivision and/or each proposed sublot. Such systems shall conform to the requirements of the Village Road Commissioner.
(d) Drainage Improvements. Closed sewers of an approved type and size shall be required as part of the construction. All drainage improvements shall be located in the road right of way or in drainage easements. If any storm drainage improvement is required to cross private property, easements shall be obtained by the sub-divider or developer for the construction and future maintenance. These easements shall be shown on the construction plans.
Storm water runoff control shall be accomplished by storm water detention and/or retention. Such detention and/or retention may be accomplished in oversized pipes or other methods acceptable to the Village Road Commissioner and easements shall be provided for such improvements. After the final acceptance of such improvements and the release of the maintenance guarantee, the Village of Lordstown shall assume maintenance responsibilities for such improvements.
No natural drainage course shall be altered in such a way as to change the amount or direction of flow and no fill, buildings, nor structures shall be placed in, on, or over it unless provision is made for the flow of water in a manner satisfactory to the Road Commissioner. An easement shall be provided on both sides of an existing surface drainage course for the purpose of maintaining, protecting, widening, deepening, enclosing, or otherwise improving such stream for drainage purposes.
Storm drainage from lots, including drain tile around basements, shall not be permitted to discharge into any sanitary sewer facility, but shall connect to an adequate drainage outlet.
Where curb or curb and gutter type pavement is used, provisions shall be made for adequate storm drainage lines and inlets to insure proper drainage of the pavement. All circular culverts shall be reinforced concrete pipe, or HDPE, with sealed joints having a diameter to be determined by the Road Commissioner, but in no case less than (12) inches. Where special drainage designs are necessary, such designs in detail must be submitted to the Village Road Commissioner for approval in advance of the completion of the construction plans.
The velocity of flow in an open ditch shall not exceed four (4) feet per second in soil ditches or six (6) feet per second in turf gutters. Paved gutters will be required if velocities of flow are greater than those specified or if it is otherwise likely that destructive erosion will result. Drainage ditches shall not be permitted to discharge into any sanitary sewer facility.
All trenches for storm drainage sewers within pavement or driveway areas, shall be backfilled with premium material to a point within a minimum of six (6) inches of the sub-grade and to a point of three (3) feet outside the pavement edge or three (3) feet back of curb.
(e) Property Line Swales. Subdivision planning and layout requires adequate surface drainage away from buildings. This is obtained by sloping the finished grade at approximately 1 percent in all directions away from the buildings. The layout often calls for a swale to be located along the back property line which then drains longitudinally through the lot. The final grading plan for the lot layout can readily be done, in such a manner as to cause up to 6 inches of depth of temporary ponding facilities along the property line. Temporary ponding facilities along the rear lot line may be percolated into the ground. In the latter case, 6 inches of water could be expected to percolate into the ground the same day on which the rainfall occurred. Prior to the planning of property line swale ponding, the planner should make sure that the neighborhood does not have clay or shale sub-soil condition affecting the building foundations. In such cases where significantly adverse sub-soil conditions exist, water should not be ponded or percolated into the ground.
(f) Reserved.
(g) Reserved.
(h) Ownership. The improvement plans and final plat for a proposed subdivision shall clearly delineate what entity shall own and maintain in perpetuity all storm water management improvements within and/or required for the proposed subdivision.
Commercial/Industrial retention ponds may be considered with the understanding that the owner will properly maintain the retention pond so that it is kept mowable at all times during the mowing season.
(Ord. 56-2005. Passed 10-3-05.)