(A) The requirements and standards of this section shall apply to all new developments and redevelopment projects, including the disturbance of land activities of any kind, on any lot, tract, parcel, or land or any portion thereof. The intent of these regulations is to minimize the discharge and transport of pollutants to storm drain systems and prevent the deterioration of water quality.
(B) All new construction of new developments or redevelopment projects within the city watershed shall include a notice of intent, storm water management plans, and comprehensive drainage plans as described in this section. These plans shall be subject to the review and approval of the City Engineer or designated representative and may receive approval from the Director, the Municipal Utility Commission, and City Council.
(C) The following activities shall be exempt from the requirements of this section, except that no activity shall be exempt from the management of the discharge of sediment or any other form of water pollution that may leave any parcel, site, or tract:
(1) Agricultural land management activities, as defined in this article;
(2) Additions or modifications to existing detached single-family dwellings of a size less than 1,000 square feet;
(3) Activities that result in impervious surface area of less than 3,000 square feet (excluding single-family dwellings) regardless of the ratio of impervious surface area to total site area; however, a phased contiguous construction project shall be measured by the size of all planned or contemplated phases. Each phase shall be required to meet the requirements of this article; and
(4) Any development activities that the “Board” determines are regulated under specific state laws and which provide for managing storm water runoff will be exempt from the provision of the article and the requirements of providing storm water management and erosion control.
(D) Technical, administrative, or procedural matters may be modified by the Director as needed to meet the objectives and policies defined in this article, so long as such modifications are not contrary to or beyond the intent of the objectives and policies included in this article.
(E) Uniform requirements shall be applied to each regulated project site. These requirements shall be based upon the criterion that post-development storm water peak runoff rates of flow must not exceed the pre-development peak runoff rates of flow. In redevelopment projects, a peak runoff rate of flow reduction of 10% from the pre-existing peak runoff rate of flow must be achieved. However, no reduction shall be required beyond the peak runoff rate of flow that would occur from the parcel in its natural, undeveloped state.
(F) For construction that results in impervious areas of 3,000 square feet and greater (with the exception of single-family residential housing) or, if the ratio of impervious surface area to total site area is greater than 50%, a Storm Water Management and Erosion Control Plan will be required in order to qualify for a storm water permit. The Plan shall include the following information:
(1) Descriptive information:
(a) Title block with:
1. Development name;
2. Owner;
3. Design firm;
4. Authorized registered professional engineer stamp, signature, and date;
5. Legend;
6. North arrow;
7. Vicinity map;
8. Scale;
9. Sheet numbers;
10. Date; and
11. Revision numbers and dates.
(b) Topographical features:
1. Original and proposed contours at intervals no greater than two vertical feet;
2. Existing drainage components, i.e., streams, ponds, pipes, and the like;
3. Property boundary lines;
4. Existing streets, buildings, and utilities;
5. One hundred-year floodplain;
6. Off-site drainage entering site; and
7. Original drawing no larger than 24-inches by 36-inches and at a scale from one- inch equals ten feet to one-inch equals 50 feet.
(c) Site plan:
1. Existing and proposed structures, roads, buildings, and paved areas;
2. Existing and proposed storm water management system and components including sizes, lengths, pertinent elevations, and the like;
3. Where and how proposed storm water management system will be connected to existing systems;
4. Location and grade of all swales including cross sections;
5. Location and design of all other best management structures/implementations;
6. Sedimentation and erosion control measures are required. Refer to the most current edition of the state’s Department of Transportation Erosion and Sedimentation Control Handbook for acceptable means and methods;
7. Existing and proposed ground cover;
8. Total impervious area; and
9. Control release facilities showing cross-sections and profiles.
(d) Final as-built drawings:
1. Submitted in AutoCAD, DXF, or DWG or another authorized file format;
2. Show all revised contours and appropriate “spot elevations”;
3. Show location, length, sizes, and pertinent elevations of the storm water management system;
4. All impervious areas shall be accurately depicted; and
5. Failure to provide final as-built drawings within three months of substantial project completion will cause the utility to prepare these drawings. The responsible party shall be charged for this service. The Director may extend this time as deemed necessary.
(e) Design standards:
1. Flow rates shall be calculated by use of the Rational Method or SCS TR-55 Method unless sufficient justification for use of another method is approved by the Director;
2. The minimum “time of concentration” to be used in the calculations shall be six minutes; and
3. Detention structures shall be designed in such a manner that the post-construction peak runoff rate of flow shall be equal to or less than the pre-construction peak runoff of flow rate for two-year/24-hour and ten-year/24-hour storms. Additional measures may be considered by the Director in critical area watersheds. In redevelopment projects, a peak runoff reduction of 10% from the pre- existing peak runoff rate of flow must be achieved; however, no reduction shall be required beyond the peak runoff rate of flow that would occur from the parcel in its natural, undeveloped state.
(f) Design backup:
1. Calculations of volumetric runoff and peak runoff rate of flow for both pre- development and post-development;
2. Calculations for storm water detention/retention facility and other system elements including description and rationale supporting the design methodology; and
3. Operation and Maintenance Manual for private storm water control facilities.
(g) Sedimentation and erosion control measures are required. Refer to the most current edition of the state’s Department of Transportation Erosion and Sedimentation Control Handbook for acceptable means and methods.
(G) All development and/or redevelopment projects shall minimize the impact to the water environment by applying structural and/or nonstructural management practices selected to address site- specific conditions.
(H) No construction shall be performed in a manner that will negatively impact the water environment in the vicinity of construction or in other areas, regardless of whether this impact is manifested by flow restrictions, increased runoff, diminishing channel or floodplain storage capacity, harm to aquatic life, or any other manifestation of negative impact.
(I) New construction or reconstruction shall be permitted only after temporary or permanent erosion and sediment control management practices have been placed and are operational to the satisfaction of the Director. The Director may halt construction, void a permit, or take other enforcement actions consistent with this article upon a finding of inadequate erosion and sediment control management practices upon a site or property subject to the provisions of this article.
(J) All active construction sites shall be inspected by the owner no less than weekly and within 24 hours after a 0.25-inch rain event to ensure and verify effective erosion and sediment control. The owner shall maintain records of these inspections. The Director may halt construction on properties that do not provide satisfactory proof of compliance with this requirement.
(K) Waivers for providing storm water management include the following.
(1) Storm Water Management and Erosion Control Plan waivers shall be granted by the Director with approval of the Board only to those projects within areas where Watershed Management Plans have been developed and/or where the WVDEP, the county, and the city deem appropriate. A written request for waiver must be submitted to the Director in a form that is provided by the Municipal Utility Commission.
(2) If a comprehensive Watershed Management Plan has not been developed, then a waiver may be granted to specific projects on a case-by-case basis that do not increase the post-development peak discharge over that of the pre-development peak discharge for undisturbed land. The Director, with approval of the Board, may not waive the minimum for storm water management of water quality protection as described in division (I) above.
(3) Any requirements beyond those described in division (I) above may be waived by the Director, with approval of the Board, if the Director finds that meeting the minimum on-site storm water management requirements is not feasible due to the unique natural or existing physical characteristics of a site or that the property owner would suffer an undue hardship if required to meet the full requirements of this regulation. To be eligible for a waiver, the applicant must also demonstrate to the satisfaction of the Director and the Board that the waiver will not result in any of the following impacts to downstream waterways:
(a) Deterioration of existing culverts, bridges, dams, and other structures;
(b) Degradation of biological functions or habitat;
(c) Accelerated stream bank or streambed erosion; or
(d) Increased threat of flood damage to public health, life, and/or property.
(4) Where compliance with the full requirements for on-site storm water management is waived, the applicant shall satisfy storm water management requirements by accomplishing a mitigation measure approved by the Director. Mitigation measures may include, but are not limited to, the following:
(a) Alternative means for on-site management of storm water discharges that have been established in a storm water management plan that has been approved by the Director;
(b) The creation of appropriately designed and constructed storm water management facility or drainage improvements on other properties, public or private, that currently lack storm water management facilities. This alternative facility must provide a level of storm water control that is equal to or greater than that which would be afforded by the waived on-site practices and there must be a legally obligated entity responsible for the long-term operation and maintenance of the off-site practice. The Director shall, to the maximum extent practical, ensure that the benefits arising from the off-site practice shall be realized in the same basin/watershed as the waived management practice;
(c) The purchase and donation of privately owned lands to the city or the grant of an easement to the city, to be dedicated to preservation, reforestation, and/or the creation of green space, wetlands, or permanent buffer areas to protect water quality and aquatic habitat. Any mitigation measure shall provide a level of environmental protection and/or improvement that is, in the sole discretion of the Director, approximately equal to or greater than that which would have been provided by the waived practice; and
(d) Any mitigation measure shall provide a level of environmental protection and/or improvement that is, in the sole discretion of the Director, approximately equal to or greater than that which would have been provided by the waived practice.
(Prior Code, § 932.20)
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