(A) The requirements of these performance standards shall apply to all new and redeveloped sites with projects that fall under site plan review. These requirements shall apply to all public and private sites within the village, regardless of whether the storm water outlet(s) from the site discharge to a designated county drain, village storm sewer system, waters of the state or any other types of conveyance. These requirements shall also apply to sites under the control of public agencies, such as schools, federal and state government facilities, and other entities that might not otherwise be subject to site plan review procedures and requirements as set forth in other sections of the village's codified ordinances. The applicant, in his or her plan submittals for site plan approval, shall demonstrate compliance with these performance standards and shall be responsible for evaluating the elected best management practices.
(B) Storm water management areas and facilities, whether on-site or off-site, shall be designed, constructed and maintained to prevent flooding and protect water quality. In order to be approved, all storm water management plans must meet the following performance standards:
(1) Storm event basis. The design of retention storm water management systems shall be based upon a 25-year frequency, 24-hour duration storm event.
(2) Runoff. Runoff leaving the site shall be controlled to a non-erosive velocity, both during and after construction.
(3) Minimum treatment volume. A minimum treatment volume is established to provide pollutant removal (pre-treatment) for common precipitation events. The minimum treatment volume standard shall be one half-inch of runoff from the entire site.
(4) Channel protection criteria. Channel protection criteria are established to protect stream channel bed and banks from excessive flows. The channel protection criteria is to maintain post-development site runoff volume and peak flow rate at or below existing levels for all storms up to the 25-year, 24-hour event. EXISTING LEVELS means the runoff flow volume and rate for the last land use prior to the planned new development or redevelopment.
(5) Riparian buffers.
(a) A riparian buffer shall be considered for lands adjacent to streams, rivers and wetlands that are contagious to these natural features.
(b) Riparian buffers shall also be considered for noncontiguous wetlands if the full extent of the wetlands as a natural feature is five acres or greater.
(c) Where applicable, the following guidelines shall apply.
1. The riparian buffer shall serve as a natural conservation area, where the principal best management practice is vegetative filtering and the conservation of trees, shrubs and herbaceous vegetation.
2. The riparian buffer is a storm water management measure to control soil loss and reduce water quality degradation caused by nutrients, animal wastes, toxic chemicals, sediments and runoff.
3. The riparian buffer shall begin at the edge of the stream bank of the active channel or the wetland boundary.
4. The riparian buffer shall be composed of two distinct management zones in order to proscribe both permitted and restricted uses that provide progressive best management practices for storm water quality protection.
a. Zone 1 - Stream Side Protection. Zone 1 begins at the edge of the stream bank or wetland and extends 25 feet up gradient and perpendicular to the protected natural feature. Zone 1 shall contain undisturbed natural vegetation. Allowable uses within this zone are restricted to flood control structures, utility rights-of-way, foot paths, and road crossings where permitted. Highly restricted vegetative trimmings and removal of woody brush/trees is allowed to provide a limited view shed of the protected natural feature.
b. Zone 2 - Outer Zone. The Outer Zone (Zone 2) begins at the outer limit of the Stream Side Protection Zone (Zone 1) and extends 25 feet. Allowable uses within the Outer Zone are biking or hiking paths, approved storm water management facilities, approved recreational facilities, and removal of mature tree cover. Shrub and herbaceous ground cover are to be protected from disturbance.
(6) Riparian buffer permitted activities. The following activities are permitted within Zones 1 and 2, provided the activity is undertaken in accordance within recognized best management practices. Other regulatory restrictions may apply, such as actions that may require separate federal, state or local permit or permit-by-rule provisions.
(a) Stream restoration projects conducted with advice and guidance of the county conservation district.
(b) Removal of individual trees in danger of falling, causing damage to structures, or causing blockage of the stream.
(c) Timber-cutting techniques approved by state agencies, under advice and guidance, for purposes of forest management due to pest infestation, disease or threat from fire.
(d) Riparian buffers are intended to grow into their vegetative target state naturally. However, active methods to enhance successional process, reforestation or to ensure preservation and propagation of the buffer are allowed.
(7) Riparian buffer width. The width of each zone may need to be increased if steep slopes are within close proximity of the protected natural feature. Guidelines of the U.S. Geological Service may be used to determine the required equivalent length of vegetative filter capacity needed for slopes in excess of 15%.
(C) Storm water storage facilities that protect water quality and prevent adverse flooding on-site and off-site shall be required for all sites of one acre or more. In order to improve the quality of storm water runoff and reduce the discharge of sediment into wetlands, watercourses, roadways, structures and other property within and downstream of the village, the following techniques, (1) through (6), and standards, (7) through (9), shall be used:
(1) Infiltration of runoff, provided that soils and groundwater conditions are suitable.
(2) Retention basins with a fixed minimum water elevation between runoff events (e.g., wet ponds).
(3) Detention basins that drain completely after a storm event (e.g., dry basin), but that discharge storm water to wetlands, or constructed basins that trap sediment carried by storm water runoff.
(4) Detention basins that hold storm water for more than 24 hours before completely draining to become a dry basin (extended detention basins).
(5) Detention basins with a positive outlet shall be designed to hold runoff from a ten-year storm event, as a minimum. Retention basins without a positive outlet shall be designed to hold runoff from a 100-year storm event.
(6) Natural watercourses shall not be dredged, cleared of vegetation, deepened, widened, straightened, stabilized or otherwise altered without approval from the Michigan Department of Natural Resources and Calhoun County Drain Commissioner.
(7) Discharge of runoff from commercial and industrial sites that may contain oil, grease, toxic chemicals, or other polluting materials shall be prohibited, unless approval has been obtained from the Michigan Department of Natural Resources and Calhoun County Drain Commissioner.
(8) The use of storm water management areas and vegetated buffer areas as open space, recreation and conservation areas shall be encouraged.
(9) Right of entry, furnishing information. Representatives of the village, State of Michigan, DEQ, and Calhoun County Drain Commission shall have the right to entry for inspection, at any reasonable time, any property served by a storm water drainage facility. On request, the owner, lessees, or occupants of any property so served shall furnish to the inspection agency any pertinent information regarding the drainage system or systems on such property. The refusal of such information or refusal of access, when requested, shall be deemed evidence of the presence of unlawful discharge.
(D) Pipes, conduits, ditches, drains or other conveyance facilities shall not discharge directly to the following receiving waters without providing the minimum treatment volume and channel protection criteria:
(1) Any natural watercourses, including lakes, ponds, rivers and streams.
(2) Wetlands with unique or natural wildlife or habitat characteristics, as defined by a professional wetlands delineation specialist, biologist or ecologist.
(3) Wetlands within a 500-foot discharge of any natural lake or pond.
(4) Wetlands within a 100-foot distance of any river or stream.
(E) Discharge from storm water conveyance facilities shall be routed through swales, vegetated buffer strips, storm water basins, hydrologically isolated wetlands, and other facilities designed to decrease runoff below velocity and volume, allow for natural infiltration, allow suspended solids to settle, and remove pollutants.
(F) If wetlands are proposed for storm water detention, runoff must be diffused to non-erosive velocities before it reaches the wetlands.
(G) Monitoring and access of discharges. As a condition to having a direct connection to waters of the state or to the municipal storm sewer system, an industrial or commercial facility shall permit the village to enter and inspect, at reasonable times and in a reasonable manner, to determine compliance with this chapter. Such entry and inspection may include, but not be limited to, sampling, analysis, dye testing, smoke testing, remote video inspection (televising), and examination and/or copying of records required by this chapter to be maintained.
(H) The village may require a commercial or industrial facility that discharges into the storm water system to install devices as are reasonably necessary to monitor and/or sample the facility's storm water discharge. In the alternative, and at its option, the village may install such devices. All such devices shall be calibrated to ensure accuracy.
(I) (1) The village is hereby empowered to seek assistance from any court of competent jurisdiction in obtaining entry to a facility, if the village:
(a) Has been refused access to any part of the premises from which storm water originates and/or is discharged; and
(b) Is able to demonstrate probable cause to believe that there may be a violation of this chapter; or that there is a need to inspect and/or sample as part of a routine inspection and sampling program designed to verify compliance with this chapter, or any order issued hereunder; or to protect the overall public health, safety and welfare of the community.
(2) In addition, or in the alternative, the village, if denied entry, may terminate the facility's connection to the storm water system. Such termination must be preceded by written notice to the facility and/or responsible party of such intent.
(J) Requirement to prevent, control and reduce storm water pollutants by the use of best management practices.
(1) If the owner or operator of a facility does not provide reasonable protection from illicit discharge, the village may require best management practices (BMPs) and/or storm water pollution prevention plans (SWPPPs) for a facility that discharges, or is reasonably suspected of discharging, pollution into the storm water system, at the facility’s expense.
(2) A BMP shall be consistent with the guidelines set forth in the most current MDEQ Guidebook of Best Management Practices for Michigan Watersheds, or equivalent practices and design criteria that accomplish the purposes of this chapter, as approved by the Department. A BMP and/or a SWPPP, which may be imposed even if the facility is subject to a NPDES permit, shall be communicated in writing by the village to the facility.
(Ord. 2013-02, passed 9-3-2013)