(a) Findings of Fact. It is hereby determined that land development projects and associated increases in impervious cover alter the hydrologic response of local watersheds and increase storm water runoff rates and volumes, flooding, stream channel erosion, and sediment transport and deposition; this storm water runoff contributes to increased quantities of water-borne pollutants, and; stormwater runoff, soil erosion and nonpoint source pollution can be controlled and minimized through the regulation of stormwater runoff from development sites. Therefore, the City of Dunbar establishes this set of water quality and quantity policies applicable to all surface waters to provide reasonable guidance for the regulation of storm water runoff for the purpose of protecting local water resources from degradation. It is determined that the regulation of storm water runoff discharges from land development projects and other construction activities in order to control and minimize increases in storm water runoff rates and volumes, soil erosion, stream channel erosion, and nonpoint source pollution associated with stormwater runoff is in the public interest and will prevent threats to public health and safety.
(b) Purpose. The purpose of this article is to establish minimum stormwater management requirements and controls to protect and safeguard the general health, safety and welfare of the public residing in watersheds within this jurisdiction. This article seeks to meet
that purpose through the following objectives:
(1) Minimize increases in stormwater runoff from any development in order to reduce flooding, siltation, increases in stream temperature, and streambank erosion and maintain the integrity of stream channels.
(2) Minimize increases in nonpoint source pollution caused by storm water runoff from development which would otherwise degrade local water quality.
(3) Minimize the total annual volume of surface water runoff which flows from any specific site during and following development to not exceed the pre-development hydrologic regime to the maximum extent practicable.
(4) Reduce stormwater runoff rates and volumes, soil erosion and nonpoint source pollution, wherever possible, through stormwater management controls and to ensure that these management controls are properly maintained and pose no threat to public safety.
(c) Applicability. This article shall be applicable to all subdivision or site plan applications, unless eligible for an exemption or granted a waiver by the City of Dunbar under the specifications of Section 926.04
. The article also applies to land development activities that are smaller than the minimum applicability criteria if such activities are part of a larger common plan of development that meets the following applicability criteria, even though multiple separate and distinct land development activities may take place at different times on different schedules. In addition, all plans must also be reviewed by local environmental protection officials to ensure that established water quality standards will be maintained during and after development of the site and that post construction runoff levels are consistent with any local and regional watershed plans.
To prevent the adverse impacts of stormwater runoff, the City of Dunbar has developed a set of performance standards that must be met at new development sites. These standards apply to any construction activity disturbing 2500 or more square feet of land. The following activities may be exempt from these stormwater performance criteria:
(1) Any logging and agricultural activity which is consistent with an approved soil conservation plan or a timber management plan prepared or approved by the WVDEP as applicable.
(2) Additions or modifications to existing single family structures.
(3) Developments that do not disturb more than 2500 square feet of land, provided they are not part of a larger common development plan; and do not create more than 1000 square feet of impervious cover.
(4) Repairs to any stormwater treatment practice deemed necessary by the City of Dunbar. When a site development plan is submitted that qualifies as a redevelopment project as defined in Section 926.02
, decisions on permitting and on-site storm water requirements shall be governed by special stormwater sizing criteria found in the current storm water design manual. This criteria is dependent on the amount of impervious area created by the redevelopment and its impact on water quality. Final authorization of all redevelopment projects will be determined after a review by the City of Dunbar.
Construction activities that disturb less than 2500 square feet of land do not have to file a stormwater management plan, but must comply with established erosion and sediment control measures. Such standards will be issued with a City of Dunbar building permit.
(d) Compatibility with Other Permit and Ordinance Requirements. This article is not intended to interfere with, abrogate, or annul any other ordinance, rule or regulation, statute, or other provision of law. The requirements of this article should be considered minimum requirements, and where any provision of this article imposes restrictions different from those imposed by any other ordinance, rule or regulation, or other provision of law, whichever provisions are more restrictive or impose higher protective standards for human health or the environment shall be considered to take precedence.
(e) Severability. If the provisions of any section, subsection, paragraph, subdivision or clause of this article shall be judged invalid by a court of competent jurisdiction, such order of judgment shall not affect or invalidate the remainder of any article, section, subsection, paragraph, subdivision or clause of this article.
(f) Development of a Stormwater Design Manual.
(1) The City of Dunbar may furnish additional policy, criteria and information including specifications and standards, for the proper implementation of the requirements of this article and may provide such information in the form of a Stormwater Design Manual.
(2) This manual will include a list of acceptable stormwater treatment practices, including the specific design criteria and operation and maintenance requirements for each stormwater practice. The manual may be updated and expanded from time to time, at the discretion of the local review authority, based on improvements in engineering, science, monitoring and local maintenance experience. Stormwater treatment practices that are designed and constructed in accordance with these design and sizing criteria will be presumed to meet the minimum water quality performance standards.
(Ord. 654. Passed 7-6-10.)
(a) "Accelerated Erosion" means erosion caused by development activities that exceeds the natural processes by which the surface of the land is worn away by the action of water, wind, or chemical action.
(b) "Applicant" means a property owner or agent of a property owner who has filed an application for a stormwater management permit.
(c) "Building" means any structure, either temporary or permanent, having walls and a roof, designed for the shelter of any person, animal, or property, and occupying more than 100 square feet of area.
(d) "Channel" means a natural or artificial watercourse with a definite bed and banks that conducts continuously or periodically flowing water.
(e) "Dedication" means the deliberate appropriation of property by its owner for general public use.
(f) "Detention" means the temporary storage of storm runoff in a stormwater management practice with the goals of controlling peak discharge rates and providing gravity settling of pollutants.
(g) "Detention Facility" means a detention basin or alternative structure designed for the purpose of temporary storage of stream flow or surface runoff and gradual release of stored water at controlled rates.
(h) "Developer" means a person who undertakes land disturbance activities.
(i) "Drainage Easement" means a legal right granted by a landowner to a grantee allowing the use of private land for stormwater management purposes.
(j) "Erosion and Sediment Control Plan" means a plan that is designed to minimize the accelerated erosion and sediment runoff at a site during construction activities.
(k) "Fee in Lieu" means a payment of money in place of meeting all or part of the storm water performance standards required by this article.
(l) "Hotspot" means an area where land use or activities generate highly contaminated runoff, with concentrations of pollutants in excess of those typically found in stormwater.
(m) "Hydrologic Soil Group (HSG)" means a Natural Resource Conservation Service classification system in which soils are categorized into four runoff potential groups. The groups range from A soils, with high permeability and little runoff production, to D soils, which have low permeability rates and produce much more runoff.
(n) "Impervious Cover" means those surfaces that cannot effectively infiltrate rainfall (e.g., building rooftops, pavement, sidewalks, driveways, etc).
(o) "Industrial Stormwater Permit" means an National Pollutant Discharge Elimination System permit issued to a commercial industry or group of industries which regulates the pollutant levels associated with industrial stormwater discharges or specifies on-site pollution control strategies.
(p) "Infiltration" means the process of percolating stormwater into the subsoil.
(q) "Infiltration Facility" means any structure or device designed to infiltrate retained water to the subsurface. These facilities may be above grade or below grade.
(r) "Jurisdictional Wetland" means an area that is inundated or saturated by surface water or groundwater at a frequency and duration sufficient to support a prevalence of vegetation typically adapted for life in saturated soil conditions, commonly known as hydrophytic vegetation.
(s) "Land Disturbance Activity" means any activity which changes the volume or peak flow discharge rate of rainfall runoff from the land surface. This may include the grading, digging, cutting, scraping, or excavating of soil, placement of fill materials, paving, construction, substantial removal of vegetation, or any activity which bares soil or rock or involves the diversion or piping of any natural or man-made watercourse.
(t) "Landowner" means the legal or beneficial owner of land, including those holding the right to purchase or lease the land, or any other person holding proprietary rights in the land.
(u) "Maintenance Agreement" means a legally recorded document that acts as a property deed restriction, and which provides for long-term maintenance of storm water management practices.
(v) "Nonpoint Source Pollution" means pollution from any source other than from any discernible, confined, and discrete conveyances, and shall include, but not be limited to, pollutants from agricultural, silvicultural, mining, construction, subsurface disposal and urban runoff sources.
(w) "Offset Fee" means a monetary compensation paid to a local government for failure to meet pollutant load reduction targets.
(x) "Off-Site Facility" means a stormwater management measure located outside the subject property boundary described in the permit application for land development activity.
(y) "On-Site Facility" means a stormwater management measure located within the subject property boundary described in the permit application for land development activity.
(z) "Recharge" means the replenishment of underground water reserves.
(aa) "Redevelopment" means any construction, alteration or improvement exceeding square feet in areas where existing land use is high density commercial, industrial, institutional or multi-family residential.
(bb) "Stop Work Order" means an order issued which requires that all construction activity on a site be stopped.
(cc) "Storm Water Management" means the use of structural or non-structural practices that are designed to reduce storm water runoff pollutant loads, discharge volumes, peak flow discharge rates and detrimental changes in stream temperature that affect water quality and habitat.
(dd) "Storm Water Retrofit" means a stormwater management practice designed for an existing development site that previously had either no stormwater management practice in place or a practice inadequate to meet the storm water management requirements of the site.
(ee) "Stormwater Runoff' means flow on the surface of the ground, resulting from precipitation.
(ff) "Stormwater Treatment Practices (STPs)" means measures, either structural or nonstructural, that are determined to be the most effective, practical means of preventing or reducing point source or nonpoint source pollution inputs to storm water runoff and water bodies.
(gg) "Water Quality Volume (WQv)" means the storage needed to capture and treat 90% of the average annual stormwater runoff volume. Numerically (WQv) will vary as a function of long term rainfall statistical data.
(hh) "Watercourse" means a permanent or intermittent stream or other body of water, either natural or man-made, which gathers or carries surface water.
(ii) "WVDEP" means the West Virginia Department of Environmental Protection.
(Ord. 654. Passed 7-6-10.)