CHAPTER 16-6: 2007 CITY OF PRESCOTT POST CONSTRUCTION STORMWATER RUNOFF CODE
16-6-1: ADOPTION OF THE 2007 CITY OF PRESCOTT POST CONSTRUCTION STORMWATER RUNOFF CODE:
16-6-1 ADOPTION OF THE 2007 CITY OF PRESCOTT POST CONSTRUCTION STORMWATER RUNOFF CODE:
That certain document entitled the 2007 City of Prescott Post Construction Stormwater Runoff Code, together with all referenced standards therein and together with appendices, which document was made a public record by Resolution No. 3873-0841 is hereby adopted by this reference. (This document is show below as a courtesy to users.)
Section 1 – General Provisions
1.1 The purpose of this ordinance 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 ordinance seeks to meet that purpose through the following objectives:
1. Minimize increases in stormwater runoff from any development in order to reduce flooding, siltation and stream-bank erosion and maintain the integrity of stream channels;
2. Minimize increases in non-point source pollution caused by stormwater 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 non-point 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.
1.2 This ordinance shall be applicable to all subdivision or site plan applications, unless eligible for an exemption or granted a waiver by the City of Prescott under the specifications of Section 4 of this ordinance. The ordinance 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.
1.3 This ordinance is not intended to interfere with, abrogate, or annul any other ordinance, rule or regulation, stature, or other provision of law. The requirements of this ordinance should be considered minimum requirements, and where any provision of this ordinance 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.
1.4 This Ordinance is written to be compatible with, and used in conjunction to the City’s Construction Site Erosion and Sediment Control Ordinance; and any repetitive sections or requirements are intended as required under the federal Clean Water Act and the National Pollution Discharge Elimination System (NPDES) regulations.
1.5 If the provisions of any article, section, subsection, paragraph, subdivision or clause of this ordinance 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 ordinance.
1.6 The City of Prescott may furnish additional policy, criteria and information including specifications and standards, for the proper implementation of the requirements of this ordinance and may provide such information by amending the City of Prescott Drainage Criteria Manual. 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. 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.
Section 2 – Definitions
Accelerated Erosion – 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.
Enforcement Agency – Any employees or designees of the Director of Public Works designated to enforce this regulation.
Applicant – Any property owner or agent of a property owner who has filed an application for a stormwater management permit.
Arizona Department of Environmental Quality (ADEQ) – is the state agency charged with enforcement of environmental laws and regulations.
Building – 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.
Channel – Any natural or artificial watercourse with a definite bed and banks that conducts continuously or periodically flowing water.
Dedication – The deliberate appropriation of property by its owner for general public use.
Detention – 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.
Detention Facility – A 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.
Developer – Any person who undertakes land disturbance activities.
Drainage Easement – A legal right granted by a landowner to a grantee allowing the use of private land for stormwater management purposes.
Drainage Way – Any man-made or natural channel or device that conveys concentrated or sheet-flow surface runoff through, across or over a site.
Fee in Lieu – A payment of money in place of meeting all or part of the storm water performance standards required by this ordinance.
Hotspot – An area where land use or activities generate highly contaminated runoff, with concentrations of pollutants in excess of those typically found in stormwater.
Impervious Cover – Surfaces that cannot effectively infiltrate rainfall (e.g., building rooftops, pavement, sidewalks, driveways, etc.).
Industrial Stormwater Permit – The 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.
Infiltration – The process of percolating or absorption of stormwater into surface and subsurface soils or other filtration mediums.
Infiltration Facility – Any structure or device designed to accommodate or promote infiltration of captured site runoff for pollutant removal. These facilities may be above grade or below grade.
Jurisdictional Wetland – 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.
Land Disturbance Activity – 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.
Landowner – 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.
Maintenance Agreement – Any legally recorded document that acts as a property deed restriction, and which provides for long-term maintenance of storm water management practices.
Non-point Source Pollution – Pollution from any source other than from any discernible, confined, and discrete conveyances, and shall include, but not be limited to, pollutants from agricultural, mining, construction, subsurface disposal and urban runoff sources.
Offset Fee – A monetary compensation paid to a local government for failure to meet pollutant load reduction targets.
Off-Site Facility – A stormwater management measure located outside the subject property boundary described in the permit application for land development activity.
On-Site Facility – A stormwater management measure located within the subject property boundary described in the permit application for land development activity.
Site – A parcel of land or a contiguous combination thereof, where grading work is performed as a single unified operation.
Stabilization – The use of practices that prevent exposed soil from eroding.
Start of Construction – The first land-disturbing activity associated with a development, including land preparation such as clearing, grading, and filling or any other site related activity.
Stop Work Order – An order issued which requires that all construction activity on a site be stopped.
Stormwater Management – 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.
Stormwater Runoff – Flow on the surface of the ground, resulting from precipitation.
Stormwater Treatment Practices (STP) – Measures, either structural or nonstructural, that are determined to be the most effective, practical means of preventing or reducing point source or non-point source pollution inputs to stormwater runoff and water bodies.
Water Quality Volume (WQV) – 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.
Watercourse – Any body of water, including but not limited to lakes, ponds, seasonal and perennial creeks, and wetlands delineated by the City of Prescott.
Waterway – Any channel or device that directs surface runoff to a watercourse or to a public storm drain.
Section 3 – Permit Requirements
All applicable aspects of this code shall be reviewed and approved as part of the City of Prescott Site Disturbance and Grading Permit as required under City of Prescott development and permitting regulations.
Section 4 – Waivers to Stormwater Management Requirements
4.1 Requests to waive the stormwater management plan requirements shall be submitted to the City of Prescott for review. The minimum requirements for stormwater management may be waived in whole or in part upon written request of the applicant, provided that at least one of the following conditions applies:
1. Alternative minimum requirements for on-site management of stormwater discharges have been established in a stormwater management plan that has been approved by the City of Prescott.
2. Provisions are made to manage stormwater by an off-site facility approved by the City of Prescott. The off-site facility is required to be in place, to be designed and adequately sized to provide a level of stormwater control that is equal to or greater than that which would be afforded by on-site practices and there is a legally obligated entity responsible for long-term operation and maintenance of the stormwater practice.
4.2 Where compliance with minimum requirements for stormwater management is waived, the applicant will satisfy the minimum requirements by meeting one of the mitigation measures selected by the City of Prescott. Mitigation measures may include, but are not limited to, the following:
1. The purchase and donation of privately owned lands, or the grant of an easement to be dedicated for preservation and/or reforestation. These lands should be located adjacent to the stream corridor in order to provide permanent buffer areas to protect water quality and aquatic habitat.
2. The creation of a stormwater management facility or other drainage improvements on previously developed properties, public or private, that currently lack stormwater management facilities designed and constructed in accordance with the purposes and standards of this ordinance.
3. Monetary contributions (Fee-in-Lieu) to fund stormwater management activities such as research and studies (e.g., regional wetland delineation studies, stream monitoring studies for water quality and macro-invertebrates, stream flow monitoring, threatened and endangered species studies, hydrologic studies, and monitoring of stormwater management practices.
4.3 When an applicant obtains a waiver of the required stormwater management, the monetary contribution required shall be in accordance with a fee schedule or by an agreed valuation established by the City of Prescott. All of the monetary contributions shall be credited to an appropriate capital improvements program project, and shall be made by the developer prior to the issuance of any building permit for the development.
4.4 In lieu of a monetary contribution an applicant may, if agreed to by the City of Prescott, obtain a waiver of the required stormwater management by entering into an agreement with the City of Prescott, for the granting of an easement or the dedication of land by the applicant, to be used for the construction of an off-site stormwater management facility. The agreement shall be entered into by the applicant and the City of Prescott prior to the recording of plats or, if no record plat is required, prior to the issuance of the building permit.
Section 5 – General Performance Criteria for Stormwater Management
5.1 All site designs shall establish stormwater management practices to control the peak flow rates of stormwater discharge associated with specified design storms and reduce the generation of stormwater.
5.2 All stormwater runoff generated from new development shall not discharge untreated stormwater directly into a jurisdictional wetland, local water body, or storm sewer system without adequate treatment.
5.3 For new development, structural Stormwater Treatment Practices (STP) shall be designed to remove post development total suspended solids (TSS) by capture of the "first flush" event. It is presumed that a STP complies with this performance standard if it is:
1. Sized to capture the prescribed water quality volume (WQV).
2. Designed according to the specific performance criteria outlined in the City of Prescott Drainage Criteria Manual, ADEQ, or ADOT design manual.
3. Constructed properly.
4. Maintained regularly.
5.4 Specific channel protection shall be provided as prescribed in the current City of Prescott Drainage Criteria Manual to protect stream channels from degradation.
5.5 Stormwater discharges to critical areas with sensitive resources (i.e., swimming beaches or public recreation areas, water supply reservoirs, etc.) may be subject to additional performance criteria, or may need to utilize or restrict certain stormwater management practices.
5.6 Stormwater discharges from land uses or activities with higher potential pollutant loadings, known as "hotspots", may require the use of specific structural STPs and pollution prevention practices.
5.7 Prior to design, applicants are required to consult with the City of Prescott to determine if they are subject to additional stormwater design requirements.
5.8 The calculations for determining peak flows as found in the City of Prescott Drainage Criteria Manual shall be used for sizing all stormwater management practices.
Section 6 – Enforcement and Penalties
6.1 Any development activity that is conducted contrary to this Ordinance may be restrained by injunction or otherwise abated in a manner provided by law.
6.2 When or if the City of Prescott determines that an activity is not being carried out in accordance with the requirements of this Ordinance, it shall issue a written notice of violation to the owner of the property.
6.3 Persons receiving a notice of violation will be required to halt all construction activities. This "stop work order" will be in effect until the City of Prescott confirms that the development activity is in compliance and the violation has been satisfactorily addressed. Failure to address a notice of violation in a timely manner can result in civil, criminal, or monetary penalties in accordance with the enforcement measures authorized in this ordinance.
6.4 Civil and Criminal Penalties. In addition to or as an alternative to any penalty provided herein or by law, any person who violates the provisions of this Ordinance shall be punished by a fine of not less than Twenty-Five Hundred Dollars ($2,500.00) or by imprisonment for a period not to exceed (30) days, or both such fine and imprisonment. Such person shall be guilty of a separate offense for each day during which the violation occurs or continues.
6.5 Occupation permits may be withheld until any and all corrections to all stormwater practices have been made and accepted by the City of Prescott.
(Ord. 4983-1521, 6-7-2016)
16-6-2 PENALTY – CRIMINAL:
Any person who violates any provisions of this chapter or any provision of the codes adopted by reference pursuant to this chapter shall be guilty of a misdemeanor, and upon conviction thereof shall be punished as provided in Section 1-3-1, by a fine not exceeding two thousand five hundred dollars ($2,500.00) or by imprisonment for not more than six (6) months, or by both such fine and imprisonment, in the discretion of the City Judge. Each and every day any such violation continues shall be deemed and considered a separate offense. (Ord. 4983-1521, 6-7-2016)
16-6-3 PENALTY – CIVIL:
Any person who violates any provisions of this chapter shall be guilty of a civil violation and shall be subject to the provisions of Section 1-3-2 for each day that the violation continues. (Ord. 4637-0839, 12-11-07; eff. 01-10-08; Ord. 4983-1521, 6-7-2016)