(a) The requirements and standards of this section shall apply to all new developments and redevelopment projects. 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 developments and redevelopment projects within the designated City watershed shall include stormwater management plans and comprehensive drainage plans as described in this section. These plans shall be subject to the review of the Director, City Engineer, or designated representative and approval of the Director.
(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 or site.
(1) Agricultural Land Management.
(2) Activities that result in impervious surface area of less than 5,000 square feet and do not result in a ground disturbance greater than one (1) acre, regardless of the ratio of impervious surface area to total site area. However, a phased construction project shall be measured by the size of all planned or contemplated phases. Each phase may be required to meet the requirements of this article.
(d) All new development and redevelopment projects which are subject to the provisions of this article shall be required to obtain a stormwater permit unless exempted under the provisions of this Article. The Director shall issue a stormwater management permit for plans that meet the requirements of this section and any other requirements of this article. No City building permit shall be issued without the submission of a stormwater permit issued under the provisions of this article.
(e) 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.
(f) For construction that results in impervious area of 5,000 square feet and greater or a ground disturbance greater than one (1) acre, a Stormwater management and Erosion Control Plan will be required in order to qualify for a City 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.
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, etc.
3. Property boundary lines.
4. Existing streets, buildings, and utilities.
5. 100 year flood plain.
6. Off-Site drainage entering site.
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, paved areas.
2. Existing and proposed stormwater management system and components including sizes, lengths, pertinent elevations, etc.
3. Where and how the proposed stormwater 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 West Virginia Department of Transportation Erosion and Sedimentation Control Handbook and the West Virginia Department of Environmental Protection Sediment and Erosion Control Best Management Practices Design Manual for acceptable means and methods.
7. Existing and proposed ground cover.
8. Total impervious area.
9. Control release facilities showing cross-sections and profiles.
D. Final as-built drawings:
1. Show location, length, sizes, and pertinent elevations of the stormwater management system.
2. All impervious areas shall be accurately depicted.
3. Failure to provide final as-built drawings within three months of substantial project completion may 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.
(2) Design standards:
A. Flow rates shall be calculated by use of the Rational Method unless sufficient justification for use of another method is approved by the Director.
B. The minimum "Time of Concentration" to be used in the calculations shall be six minutes.
C. Detention structures shall be designed in such a manner that the postconstruction peak runoff rate of flow shall be equal to or less than the preconstruction 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 areas of the City watershed. In redevelopment projects, a peak runoff reduction of ten percent (10%) from the preexisting 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.
D. Development and/or redevelopment projects with a ground disturbance of one (1) acre or greater, including projects less than one (1) acre that are a part of a larger common plan of development or sale shall manage on site the first one (1) inch of rainfall from a 24-hr storm preceded by 48 hours of no measurable precipitation.
1. A reduction of 0.2 inches from the one (1) inch runoff reduction standard may be applied for redevelopment, brownfield redevelopment, high density(> 7 units per acre), Vertical Density (Floor to area ratio (FAR of 2 or> 18 units per acre), and mixed use and transit oriented development (within 1/2 mile of transit) projects. Reductions are additive up to a maximum of 0.75 inches for a project that meets four or more criteria.
2. A project that is a potential hot spot with reasonable potential for pollutant loading(s) must provide water quality treatment for associated pollutants prior to managing the first one inch of rainfall.
3. A project that is a potential hot spot with reasonable potential for pollutant loading(s) that cannot implement adequate preventive or water quality standards must properly convey storm water via a license water hauler to a permitted treatment and disposal facility or to a NPDES-permitted wastewater facility.
4. A project that discharges or proposes to discharge to any surface water or ground water that is used as a source of drinking water must comply with all applicable requirements relating to source water protection.
(3) Design backup:
A. Calculations of volumetric runoff and peak runoff rate of flow for both predevelopment and post-development.
B. Calculations for stormwater detention/retention facility and other system elements including description and rationale supporting the design methodology.
C. Operation and Maintenance Manual for private stormwater control facilities.
(4) Sedimentation and Erosion Control measures are required. Refer to the most current edition of the West Virginia Department of Environmental Protection Sediment and Erosion Control Manual 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 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 of a 0.5-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 Stormwater Management:
(1) Every applicant shall provide for storm water management as required by this section, unless a waiver of these requirements is granted by the Director. A written request for waiver must be submitted to the Director in a form that he or she prescribes.
(2) A written request for waiver must be submitted to the Director in form that provides the following information:
A. Name of Developer;
B. Mailing address;
C. Phone number;
D. Location of development;
E. Describe the circumstances for requesting a waiver;
F. Proposed alternative to meet compliance with Stormwater Ordinance related to environmental impact of construction.
(3) 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 predevelopment 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 subsection (i) of this section.
(4) Any requirement beyond those described in subsection (i) of this section may be waived by the Director, if the Director finds that meeting the minimum on-site stormwater 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 these regulations. 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.
(5) Where compliance with the full requirements for on-site stormwater management is waived, the Applicant shall satisfy stormwater 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 onsite management of stormwater discharges that have been established in a stormwater management plan that has been approved by the Director.
B. The creation of appropriately designed and constructed stormwater management facility or drainage improvements on other properties, public or private that currently lack stormwater management facilities. This alternative facility must provide a level of stormwater 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 ofthe 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.
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.
(6) Fee in lieu of stormwater management practices. Where the Director waives all or part of the minimum stormwater management requirements, and the applicant does not complete an approved mitigation project, the applicant shall be required to pay a fee in lieu of stormwater management practices, in an amount as determined by the Director. This amount shall be approximately equal to the cost of stormwater management and based on the cubic feet of storage required to stormwater management of the development in question. All of the monetary contributions shall be credited to an appropriate stormwater capital improvements program project, and shall be made by the applicant prior to the issuance of any stormwater permit for the development. (Ord. 2011-11. Passed 11-21-11.)