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HomeMy WebLinkAboutOrdinance 502.18 Surface Storme Water ORDINANCE 502 – ZONING ORDINANCE Section 502.18: SURFACE (STORM) WATER MANAGEMENT Subd. 1: Findings. The City of St. Joseph hereby finds that uncontrolled and inadequately planned use of wetlands, woodlands, natural habitat areas, areas subject to soil erosion and areas containing restrictive soils adversely affects the public health, safety and general welfare by impacting water quality and contributing to other environmental problems, creating nuisances, impairing other beneficial uses of environmental resources and hindering the ability of the City to provide adequate water, sewer, flood control and other community services. In addition, extraordinary public expenditures may be required for the protection of persons and property in such areas and in areas which may be affected by unplanned land usage. Subd. 2: Purpose. The purpose of this Chapter is to promote, preserve and enhance the natural resources within the City of St. Joseph and protect them from adverse effects occasioned by poorly sited development or incompatible activities by regulating land disturbing or development activities that would have an adverse and potentially irreversible impact on water quality and unique and fragile environmentally sensitive land; by minimizing conflicts and encouraging compatibility between land disturbing and development activities and water quality and environmentally sensitive lands; and by requiring detailed review standards and procedures for land disturbing or development activities proposed for such areas, thereby achieving a balance between urban growth and development and protection of water quality and natural areas. Subd. 3: Scope and Effect. a) Applicability. Every applicant for Subdivision approval, PUD approval, or commercial, multiple family residential or industrial permit to allow land disturbing activities must submit a surface (storm) water management plan to the City. No Subdivision approval or permit to all land disturbing activities, including but not limited to, mining, excavation, filling and grading shall be issued until approval of the surface (storm) water management plan or a waiver of the approval requirement has been obtained in conformance with the provisions of this Ordinance. The provisions of this subdivision apply to all land, public or private, located within the City. b) Exemptions. The provisions of this Chapter do not apply to: 1. Any part of a Subdivision if a plat for the Subdivision has been approved by the City on or before the effective date of this Ordinance. 2. Any land disturbing activity for which plans have been approved by the watershed management organization within six months prior to the effective date of this Ordinance. 502.18-1 ORDINANCE 502 – ZONING ORDINANCE 3. A lot for which a zoning permit has been approved on or before the effective date of this Ordinance. 4. Installation of a fence, sign, telephone and electric poles and other kinds of posts or poles. 5. Emergency work to protect life, limb or property. c) The City upon recommendation of the Planning Commission, may waive any requirement of this subdivision upon making a finding that compliance with the requirement will involve an unnecessary hardship and the waiver of such requirement will not adversely affect the standards and requirements set forth in this subdivision. The City may require as a condition of the waiver, such dedication or construction, or agreement to dedicate or construct physical improvements, facilities, property and/or easements as may be necessary to adequately meet said standards and requirements. Subd. 4: Surface (Storm) Water Management Plan Approval Procedures. a) Application. 1. A written application for surface (storm) water management plan approval, along with the proposed surface (storm) water management plan, shall be filed with the City Administrator/Clerk and shall include a statement indicating the grounds upon which the approval is requested, that the proposed use is permitted by right or as an exception in the underlying zoning district, and adequate evidence showing that the proposed use will conform to the standards set forth in this subdivision. Prior to applying for approval of a surface (storm) water management plan, an applicant may have the surface (storm) water management plans reviewed by the City. 2. Two sets of clearly legible blue or black lined copies of drawings and required information shall be submitted to the City and shall be accompanied by a receipt evidencing payment of fees (if applicable) for processing and approval as set forth in Subdivision 5 (E), and a bond when required by Subdivision 5 (D) in the amount to be calculated in accordance with that Subdivision. Drawings shall be prepared to scale appropriate to the site of the project and suitable for the review to be performed. 502.18-2 ORDINANCE 502 – ZONING ORDINANCE Subd. 5: Surface (Storm) Water Management Standards. a) When possible existing natural drainageways, wetlands, and vegetated soil surfaces must be used to convey, store, filter, and retain stormwater runoff before discharge to public waters. b) Development must be planned and conducted in a manner that will minimize the extent of disturbed areas, runoff velocities, erosion potential, and reduce and delay runoff volumes. Disturbed areas must be stabilized and protected as soon as possible and facilities or methods used to retain sediment on the site. c) When development density, topographic features, and soil and vegetation conditions are not sufficient to adequately handle stormwater runoff using natural features and vegetation, various types of constructed facilities such as diversions, settling basins, skimming devices, dikes, waterways and ponds may be used. Preference should be given to designs using surface drainage, vegetation, and infiltration rather than buried pipes and man-made materials and facilities. d) When constructed facilities are used for stormwater management, documentation must be provided by a qualified individual that they are designed and installed consistent with applicable local, state and federal standards. e) New constructed stormwater outfalls to public waters must provide for filtering or settling of suspended solids and skimming of surface debris before discharge. Subd. 6: Surface (Storm) Water Management Plan Required. a) At a minimum, the surface (storm) water management plan shall contain the following information: 1. Existing Site Map. A map of existing site conditions showing the site and immediately adjacent areas, including: A. The name and address of the applicant; a legal description of the property directly associated with the request; north point; date; scale of drawing; and number of sheets; B. Location of the tract by an insert map at a scale sufficient to clearly identify the location of the property and giving such information as the names and numbers of adjoining roads, railroads, utilities, Subdivisions, towns, and districts or other landmarks; C. Existing topography with a contour interval appropriate to the topography of the land but in no case having a contour interval greater than two (2) feet; 502.18-3 ORDINANCE 502 – ZONING ORDINANCE D. A delineation of all streams, rivers, public waters and wetlands located on and immediately adjacent to the site, including depth of water, a description of vegetation which may be found in the water, a statement of general water quality, and any classification given to the water body or wetland by the Minnesota Department of Natural Resources, the Minnesota Pollution Control Agency, and/or the United States Army Corps of Engineers; E. Location and dimensions of existing surface (storm) water drainage systems and natural drainage patterns on and immediately adjacent to the site delineating in which direction and at what rate surface (storm) water is conveyed from the site, identifying the receiving stream, river, public water, or wetland, and setting forth those areas of the unaltered site where surface (storm) water collects; F. A description of the soils of the site, including a map indicating soil types of areas to be disturbed as well as a soil report containing information on the suitability of the soils for the type of development proposed and for the type of sewage disposal proposed and describing any remedial steps to be taken by the Developer to render the soils suitable; and G. Vegetative cover and clearly delineating any vegetation proposed for removal. 2. Site Construction Plan. A site construction plan including: A. Locations and dimensions of all proposed land disturbing activities and any phasing of those activities; B. Locations and estimated dimensions of all temporary soil or dirt stockpiles; C. Locations and dimensions of all construction site erosion control measures necessary to meet the requirements of this Subdivision; D. Schedule of anticipated starting and completion date of each land disturbing activity including the installation of construction site erosion control measures needed to meet the requirements of this subdivision; and, E. Provisions for maintenance of the construction site erosion control measures during construction. 502.18-4 ORDINANCE 502 – ZONING ORDINANCE 3. Plan of Final Site Conditions. A plan of final site conditions on the same scale as the existing site map showing the site changes including: A. Finished grading shown at contours at the same interval as provided above or as required to clearly indicate the relationship of proposed changes to existing topography and remaining features; B. A drainage plan of the developed site delineating in which direction and at what rate surface (storm) water will be conveyed from the site and settling forth the areas of the site where surface (storm) water will be allowed to collect; C. The proposed size, alignment and intended use of any structures to be erected on the site; D. A clear delineation and tabulation of all areas which shall be paved or surfaced, including a description of the surfacing material to be used; and E. Any other information pertinent to the particular project which in the opinion of the applicant is necessary for the review of the project. Subd. 7: Plan Review Procedure. a) Process. Surface (storm) water management plans meeting the requirements of Subdivision 4 shall be submitted by the City Administrator/Clerk who shall consult with the City Engineer or Designee for review in accordance with the standards of Subdivision 6. The Planning Commission shall recommend approval, recommend approval with conditions, or recommend denial of the surface (storm) water management plan to the City Council. Following Planning Commission action, the surface (storm) water management plan shall be submitted to the City Council at its next available meeting. City Council action on the surface (storm) water management plan must be accomplished within sixty (60) days following the date the completed application for approval is filed with the City Administrator/Clerk. b) Duration. Approval of a plan submitted under the provisions of this Chapter shall expire one year after the date of approval unless construction has commenced in accordance with the plan. However, if prior to the expiration of the approval the applicant makes a written request to the City Administrator/Clerk for an extension of time to commence construction setting forth the reasons for the requested extension, the City may grant one extension of not greater than one single year. Receipt of any request for an extension shall be acknowledged by the City 502.18-5 ORDINANCE 502 – ZONING ORDINANCE Administrator/Clerk within fifteen (15) days. The City Administrator/Clerk, after consulting with the City Engineer shall make a decision on the extension within thirty (30) days of receipt. Any plan may be revised in the same manner as originally approved. c) A surface (storm) water management plan may be approved subject to compliance with conditions reasonable and necessary to insure that the requirements contained in this Subdivision are met. Such conditions may, among other matters, limit the size, kind or character of the proposed development; require the construction of structures, drainage facilities, storage basins, and other facilities; require replacement of vegetation; establish required monitoring procedures; stage the work over time; require alternation of the site design to insure buffering; and require the conveyance to the City or other public entity of certain lands or interests therein. d) Performance Bond. Prior to approval of any surface (storm) water management plan, the applicant shall submit an agreement to construct such required physical improvements, to dedicate property or easement, or to comply with such conditions as may have been agreed to. Such agreement shall be accompanied by a bond to cover the amount of the established cost of complying with the agreement. The agreement and bond shall guarantee completion and compliance with conditions within a specific time, which time may be extended. The adequacy, conditions and acceptability of any agreement and bond shall be determined by the City Council or any official of the City as may be designated by resolution of the City Council. e) Fees. All applications for surface (storm) water management plan approval shall be accompanied by a processing and approval fee, if applicable, and as specified by the City Council through resolution. Subd. 8: Site Dewatering. Water pumped from the site shall be treated by temporary sedimentation basins, grit chambers, sand filters, upflow chambers, hydro-cyclones, swirl concentrators or other appropriate controls as appropriate. Water may not be discharged in a manner that causes erosion or flooding of the site or receiving channels or a wetland. Subd. 9: Waste and Material Disposal. All waste and unused building materials, including but not limited to, garbage, cleaning wastes, debris, wastewater, toxic materials or hazardous materials, shall be properly disposed of off-site and not allowed to be carried by runoff into a receiving channel or surface (storm) sewer system. Subd.10: Tracking. Each site shall have graveled roads, access drives and parking areas of sufficient width and length to prevent sediment from being tracked onto public or private roadways. Any sediment reaching a public or private road shall be removed by street cleaning (not flushing) before the end of each workday. 502.18-6 ORDINANCE 502 – ZONING ORDINANCE Subd. 11: Drain Inlet Protection. All surface (storm) drain inlets shall be protected during construction until control measures are in place with a straw bale, silt fence or equivalent barrier meeting accepted design criteria, standards, and specifications contained in the Minnesota Pollution Control Agency publication entitled “Protecting Water Quality in Urban Areas”. Subd. 12: Site Erosion Control. a) The following criteria (1 through 4) apply to construction activities that result in runoff on and/or leaving the site. 1. Channeled runoff from adjacent areas passing through the site shall be diverted around disturbed areas, if practical. Otherwise, the channel shall be protected as described below. Sheetflow runoff from adjacent areas greater than ten thousand (10,000) square feet in area shall also be diverted around disturbed areas, if practical. Diverted runoff shall be conveyed in a manner that will not erode the conveyance and receiving channels. 2. All activities on the site shall be conducted in a logical sequence to minimize the area of bare soil exposed at any one time. 3. Runoff from the entire disturbed area on the site shall be controlled by meeting either Subsection (a) and (b) or (a) and (c): A. All disturbed ground left inactive for fourteen (14) or more days shall be stabilized by seeding or sodding (only available prior to September 15) or by mulching or covering or other equivalent control measure. B. For sites with more than twenty (20) acres disturbed at one time, or if a channel originates in the disturbed area, one or more temporary or permanent sedimentation basins shall be constructed. Each sedimentation basin shall have a surface area of at least one percent (1%) of the area draining to the basin and at least three (3) feet of depth and constructed in accordance with accepted design specifications. Sediment shall be removed to maintain a depth of three (3) feet. The basin discharge rate shall also be sufficiently low as to not cause erosion along the discharge channel or the receiving water. C. For sites with less than twenty (20) acres disturbed at one time, silt fences, straw bales or equivalent control measures shall be laced along all sideslope and downslope sides of the site. If a channel or 502.18-7 ORDINANCE 502 – ZONING ORDINANCE area of concentrated runoff passes through the site, silt fences shall be placed along the channel edges to reduce sediment reaching the channel. The use of silt fences, straw bales or equivalent control measures must include a maintenance and inspection schedule. 4. Any soil or dirt storage piles containing more than twenty (20) cubic yards of material should not be located with a downslope drainage length of less than twenty-five (25) feet from the toe of the pile to a roadway or drainage channel. If remaining for more than fourteen (14) days, they shall be stabilized by mulching, vegetative cover, tarps, or other means. Erosion from piles which will be in existence for less than fourteen (14) days shall be controlled by placing straw bales or silt fence barriers around the pile. In-street utility repair or construction soil or dirt storage piles located closer than twenty-five (25) feet of a roadway or drainage channel must be covered with tarps or suitable alternative control, if exposed for more than seven days, and the surface (storm) drain inlets must be protected with straw bale or other appropriate filtering barriers. Subd. 13: Surface (Storm) Water Management Criteria for Permanent Facilities. a) An applicant shall install or construct, on or for the proposed land disturbing or development activity, all surface (storm) water management facilities deemed necessary by the City and/or City Engineer to manage increased runoff so that the two-year, ten-year, and 100-year storm peak discharge rates existing before the proposed development shall not be increased, and accelerated channel erosion will not occur as a result of the proposed land disturbing or development activity. An applicant may also make an in-kind or monetary contribution to the development and maintenance of community surface (storm) water management facilities designed to serve multiple land disturbing and development activities undertaken by one (1) or more persons, including the applicant. b) The applicant shall give consideration to reducing the need for surface (storm) water management facilities by incorporating the use of natural topography and land cover such as wetlands, ponds, natural swales and depressions as they exist before development to the degree that they can accommodate the additional flow of water without compromising the integrity or quality of the wetland or pond. c) The following surface (storm) water management practices shall be investigated in developing a surface (storm) water management plan: 1. Natural infiltration of precipitation on-site, if located outside of areas considered sensitive to groundwater contamination; 2. Flow rate reduction by use of open vegetated swales and natural depressions; 502.18-8 ORDINANCE 502 – ZONING ORDINANCE 3. Surface (storm) water retention facilities; and 4. Surface (storm) water detention facilities. d) A combination of successive practices may be used to achieve the applicable minimum control requirements specified in Subsection (1) above. The applicant shall provide justification for the method selected. Subd. 14: Design Standards for Detention Facilities. Surface (storm) water detention facilities constructed in the City of St. Joseph shall be designed according to standards approved by the City Engineer. Subd. 15: Models/Methodologies. Hydrologic models and design methodologies used for the determination of runoff and analysis of surface (storm) water management structures shall be approved by the City Engineer. Plan, specification, and computations for surface (storm) water management facilities submitted for review shall be sealed and signed by a registered professional engineer. All computations shall appear on the plans submitted for review, unless otherwise approved by the City Engineer. Subd. 16: Watershed Management and Groundwater Management Plans. Surface (storm) water management plans shall be consistent with adopted watershed management plans and groundwater management plans prepared in accordance with Minnesota Statutes Chapter 123B.231 and 103B.255 respectively, and as approved by the local watershed authority as required by state law. Subd. 17: Easements. If a surface (storm) water management plan involves direction of some or all runoff off of the site, it shall be the responsibility of the applicant to obtain from adjacent property owners any necessary easements or other property interests concerning flowage of water. Subd. 18: Surface (Storm) Water Development Fees. Following approval of a surface (storm) water management plan, applicants shall pay to the City a surface (storm) water development fee based upon the square footage of the project’s Net Developable Property. “Net Developable Property” is defined as the gross land area minus the streets and other land area dedicated to the public. The per square foot fee shall be set by the City Council and adjusted from time to time by resolution. The City, in its sole discretion, may allow the applicant to offset the storm water fee, the cost of construction or maintenance of community surface (storm) water management facilities designed to serve multiple land disturbing and development activities that the developer paid for. Updated 1/2005 Section 502, Subd. 18 502.18-9