CHAPTER 25 - POST CONSTRUCTION STORMWATER CONTROL
Part of the Code of Ordinances of Exeter, RI.
The text
Sec. 25-1. - Purpose.#
Unmitigated stormwater from areas altered by development may pose public health and safety threats. Potential contaminants in stormwater runoff may include suspended solids, nitrogen, phosphorus, hydrocarbons, heavy metals, pathogenic organisms (bacteria and viruses), and road salts.
This chapter establishes the administrative mechanisms necessary for the town to ensure proper stormwater management. This chapter is written to work in conjunction with current state regulations.
(Ord. of 3-7-22, § 3)
Sec. 25-2. - Applicability.#
This chapter shall apply to any major or minor subdivision, land development project, or other development occurring within the town involving a parcel of one acre or more or a combination of parcels which equal one acre or more. No person shall engage in such development activities without receiving approval of a stormwater management plan for the development.
(Ord. of 3-7-22, § 3)
Sec. 25-3. - Technical standards.#
All applicants required to obtain approval of a stormwater management plan must develop and submit a proposed stormwater management plan, which must address stormwater management for the development that meets all the requirements of this chapter. All such stormwater management shall be consistent with the Rhode Island Stormwater Design and Installation Standards Manual and the Rhode Island Soil Erosion and Sediment Control Handbook, as amended. (1)
Performance standards. Stormwater management plans shall incorporate best management practices for water quality control, which in combination are demonstrated to reduce the average annual total suspended solids in post-development runoff by 80 percent. Development in groundwater overlay districts or watersheds where impaired waters as defined by the state's 303(d) list exist may be held to higher standards.
(2)
Disallowed stormwater best management practices. The placement of detention basins and other stormwater structures within a floodplain shall be avoided. If there is no alternative, the applicant must show what effects, if any, the tailwaters created by the floodplain will have on the outflow and effective storage capacity of the detention facility.
(3)
Facilitation of maintenance. Facilities that require maintenance shall be designed to minimize the need for regular maintenance, facilitate required maintenance, and ensure accessibility of components that require maintenance. At a minimum, all stormwater management plans must incorporate best management practices with appropriate maintenance design in accordance with the Rhode Island Stormwater Design and Installation Standards Manual, as amended; or the Rhode Island Soil Erosion and Sediment Control Handbook, as amended.
(Ord. of 3-7-22, § 3)
Sec. 25-4. - Maintenance requirements for best management practices.#
(a)
Routine maintenance and repair procedures. Preventative maintenance procedures are required to maintain the intended operation and safe condition of the stormwater management facility by greatly reducing the occurrence of problems and malfunctions. To be effective, preventative maintenance shall be performed on a regular basis and include such routine procedures as training of staff, periodic inspections, grass cutting elimination of mosquito breeding habitats, and pond maintenance. Disposal of sediment and debris must occur on a regular basis (unless otherwise specified within an approved plan), at suitable disposal sites or recycling sites and comply with applicable local, state and federal regulations.
Corrective maintenance procedures are required to correct a problem or malfunction at a stormwater management facility and to restore the facility's intended operation and safe condition. Based upon the severity of the problem, corrective maintenance must be performed on an as-needed or emergency basis and include such procedures as structural repairs, removal of debris, sediment and trash removal which threaten discharge capacity, erosion repair, snow and ice removal, fence repair, mosquito extermination, and restoration of vegetated and non-vegetated linings.
(b)
General maintenance standards for stormwater best management practices. Maintenance design and maintenance procedures for all stormwater best management practices shall be in accordance Rhode Island Stormwater Design and Installation Standards Manual, as amended, or the Rhode Island Soil Erosion and Sediment Control Handbook, as amended. Stormwater management plans shall demonstrate appropriate maintenance design and procedures for each proposed best management practice.
A maintenance schedule for each type of BMP must be included in the stormwater management plan. These schedules shall list the frequency and type of maintenance operations necessary along with the legally responsible party's name, address, and telephone number. If the stormwater drainage system is to be deeded to another party, the applicant must obtain a letter from said party acknowledging maintenance responsibility and intent of ownership.
(Ord. of 3-7-22, § 3)
Sec. 25-5. - Stormwater management plans.#
(a)
Calculations. Stormwater management plans must be in compliance with current subdivision and land development regulations and must include the following, where applicable:
(1)
The area of each subbasin as identified on final site plans.
(2)
The area of impervious surfaces (including all roads, driveways, rooftops, sidewalks, etc.) for each subbasin as identified in the Rhode Island Stormwater Design and Installation Standards Manual, as amended.
(3)
Weighted curve numbers, (CN) as determined by the SCS TR-55 method, for each subbasin as identified in the Rhode Island Stormwater Design and Installation Standards Manual, as amended.
(4)
Invert elevations for all applicable BMPs. In addition, the elevations for permanent and/or flood pool stages, including peak discharge rates for each stage, within all basins are required.
(5)
The total volume capacity for water quality BMPs (e.g., infiltration basin, detention basins, wet ponds, etc.). Volumes must be segregated into permanent and flood pool stage volumes where applicable. Furthermore, the volumes of all sediment storage (basins, forebays, etc.) areas must also be shown.
(6)
The water quality volume must also be calculated for each sub-watershed. All relevant variables such as curve numbers and time of concentration, along with the supporting computations and worksheets must be included.
(b)
Narrative description. As part of the stormwater management plan, the applicant shall include a discussion of the protection of environmental resource functions and values. The following outline is provided as guidance for preparing a narrative description for the stormwater management plan. Depending on the size and scope of the proposed project, the amount of information required by the permitting agency may vary; therefore, it is advised to consult the appropriate permitting agency for specific requirements.
(1)
Site description. General topography, soil types, current vegetative composition and relative abundance, existing infrastructure, and/or adjacent properties, identification of major resources (e.g., wetlands, groundwater, surface waters, etc.), name of receiving water(s), potential water quality and/or hydrologic impacts on resources.
(2)
Site input data. Watershed characteristics, area of all impervious surfaces, total area of site, annual mean rainfall, runoff coefficients, curve numbers for various land uses, peak discharge rates.
(3)
Land use planning and stormwater source control plan.
(4)
Best management practices. Identify the type of BMP(s) employed both during and post construction and justification for selection, including any deviation from the Rhode Island Stormwater Design and Installation Standards Manual, as amended, and the potential effect on pollutant removal efficiency.
(5)
Technical feasibility of BMPs including sizing, location, hydraulic and environmental impacts. Alternatives, which were considered but determined not to be feasible, should also be discussed.
(6)
Maintenance schedule of BMPs to be used, both during and post construction including frequency of inspection and maintenance.
(Ord. of 3-7-22, § 3)
Sec. 25-6. - Maintenance agreements.#
Maintenance agreements shall provide written, contractual documentation, which demonstrates compliance with this chapter and legal arrangements for the upkeep of stormwater facilities to assure their functionality and safety in accordance with this chapter.
Maintenance agreements, which describe all maintenance schedules and requirements, must be developed for each stormwater management facility unless the facility is dedicated to and accepted by the town. (1)
Recognition of municipal inspection requirements. Maintenance agreements shall allow the town to regularly conduct on-site inspection of the functionality and safety of stormwater management facilities. Inspection schedules shall be based on the complexity and frequency of maintenance needs and shall be determined by the town.
(2)
Record keeping for maintenance activities. Maintenance agreements shall include provisions for maintenance record keeping. All activities conducted in accordance with a maintenance agreement must be recorded in a work order and inspection log. Timely updates of the log shall be the responsibility of the stormwater management facility owner or other responsible party pursuant to this chapter. Review of the maintenance and inspection log shall be completed by the town to determine the effectiveness of operation, maintenance and safety activities. Reviews shall occur as part of each on-site inspection. Additional reviews may be made as deemed appropriate by the town.
(3)
Responsibility for maintenance to assure functionality and safety. Appropriate maintenance to assure functionality and safety of stormwater management facilities shall be the responsibility of the owner or may be assumed by another party via a written contractual arrangement in accordance with this chapter.
(4)
Alterations to maintenance agreements. Any alterations in maintenance responsibility or alterations to maintenance agreements must be reviewed and approved by the building official and the department of public works. If portions of the land serviced by a stormwater management facility are to be sold, written contractual arrangements shall be made to pass all responsibility of the maintenance agreement to the purchaser and shall be subject to review and approval of the building official. All alterations to maintenance agreements shall be recorded in accordance with this chapter.
(5)
Recordation of maintenance agreements. All maintenance agreements and alterations to maintenance agreements shall be recorded in the land evidence records of the town. Copies of all maintenance agreements and alterations to maintenance agreements shall be included in stormwater management plans. Recordation of maintenance agreements in accordance with this chapter shall be the responsibility of the owner.
(Ord. of 3-7-22, § 3)
Sec. 25-7. - Administrative fees.#
The town shall be empowered to collect fees from permit applicants, which are commensurate with the cost of administering this chapter.
(Ord. of 3-7-22, § 3)
Sec. 25-8. - Responsibility for administration.#
The building official (code enforcement officer) and the department of public works shall administer, implement, and enforce the provisions of this chapter. Any powers granted or duties imposed upon the building official or the department of public works may be delegated in writing by the director of these departments to persons or entities acting in the interest of or in the employ of the town.
(Ord. of 3-7-22, § 3)
Sec. 25-9. - Enforcement.#
(a)
Notification of violation. Whenever there is a failure to comply with the provisions of this chapter, the town shall have the right to notify the applicant/owner that he or she has five calendar days from the receipt of the notice to temporarily correct the violations and 30 calendar days from receipt of notice to permanently correct the violations.
In the event that the stormwater management facility becomes a danger to public safety or public health, or in need of maintenance or has not been maintained in accordance with the maintenance agreement, the town shall so notify the responsible person in writing by certified mail. Upon receipt of that notice, the responsible person shall have 14 calendar days to complete maintenance and repair of the facility in a manner that is approved by the municipality. If the responsible person fails or refuses to perform such maintenance and repair, the municipality may immediately proceed to do so and enforce penalties and/or liens as described herein.
(b)
Enforcement of penalties and liens. Should the applicant/owner fall to take the corrective actions, the town shall then have the right to take the available appropriate remedies it deems necessary to correct the violations including fining the owner pursuant to section 1-15 of the town Code of Ordinances and to assert a lien on the subject property in an amount equal to the costs of remedial actions. The lien shall be enforced in the manner provided or authorized by law for the enforcement of common law liens on personal property. The lien shall be recorded in the land evidence records of the town, and shall incur legal interest from the date of recording. The imposition of any penalty shall not exempt the offender from compliance with the provisions of this chapter, including assessment of a lien on the property.
Whenever a stormwater management facility is not implemented, operated, and/or maintained in accordance with the stormwater management plan that has been approved in accordance with this chapter, any penalty invoked shall be in accordance with section 1-15 of the town Code of Ordinances.
(Ord. of 3-7-22, § 3)