Village of Vicksburg, MI Performance and Design Standards

Stormwater 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 stormwater management plans must meet the following performance standards:

(1)

Runoff leaving the site shall be controlled to a nonerosive velocity, both during and after construction.

(2)

Minimum treatment volume.

(a)

A minimum treatment volume is established to provide pollutant removal (pretreatment) for prevalent precipitation events. The minimum treatment volume standard shall be one inch of runoff from the entire site. Use of the United States Geological Service (USGS) runoff curve number method is the preferred means to calculate site runoff.

(b)

Treatment methods shall be designed on a site-specific basis to achieve a minimum of 80% removal of total suspended solids (TSS), as compared with uncontrolled runoff, or discharge concentrations of TSS not to exceed 80 milligrams per liter (mg/l).

(c)

A minimum treatment volume standard is not required where site conditions are such that TSS concentrations in stormwater discharges will not exceed 80 mg/l.

(3)

Channel protection criteria.

(a)

Channel protection criteria is 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 two-year, twenty-four-hour event. "Existing levels" means the runoff flow volume and rate for the last land use prior to the planned new development or redevelopment.

(b)

An acceptable source of rainfall data for calculating runoff volume and peak flow rate is: Rainfall Frequency Atlas of the Midwest, Huff and Angel, NOAA Midwest Climate Center and Illinois State Water Survey, 1992. Methods for estimating predevelopment and post-development runoff shall follow the USGS runoff curve number method.

(c)

Curve number evaluation is described in a document titled "Computing Food Discharges for Small Ungauged Watersheds," July 2003, which can be found at www.michigan.gov/deqstormwater under "Municipal Program/MS4 Permit Guidance" (go to "Stormwater Control Resources" and select "Guidance for Calculating Runoff Volume and Peak Flow Rate").

(4)

Flood control. A flood control performance standard is required to ensure stormwater entering the Village MS4 is less than or equal to the existing (predevelopment) conditions, and on-site retainage is properly designed to protect neighboring properties. The Village Engineer or designee will review each site plan for approval on a case-by-case basis to determine if the proposed strategy meets industry standards and is appropriate for the specific site.

(5)

Riparian buffers.

(a)

A riparian buffer shall be provided for lands adjacent to streams and rivers and wetlands which are contiguous to these natural features. Riparian buffers shall also be required for noncontiguous wetlands if the full extent of the wetland as a natural feature is five acres or greater.

(b)

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. The riparian buffer is a stormwater management measure to control soil loss and reduce water quality degradation caused by nutrients, animal wastes, toxins, sediment and runoff.

(c)

The riparian buffer shall begin at the edge of the stream bank of the active channel or the wetland boundary. 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 stormwater quality protection.

[1]

Zone 1 — Stream Side Protection. Zone 1 begins at the edge of the stream bank or wetland and extends 25 feet upgradient 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 viewshed of the protected natural feature.

[2]

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 stormwater management facilities, approved recreational facilities, and removal of mature tree cover. Shrub and herbaceous ground cover are to be protected from disturbance.

[3]

Permitted activities. The following actions are permitted within Zones 1 and 2, provided the activity is undertaken in accordance with 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 Michigan Department of Environmental Quality.

[b]

Removal of individual trees that are 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.

[4]

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 United States Geological Service may be used to determine the required equivalent length of vegetative filter capacity needed for slopes in excess of 15%.

[5]

Encouragement of voluntary measures. Lands adjacent to the outer edge of the Outer Zone (Zone 2) are hereby defined as riparian lands. Riparian property owners have a unique and critical role in protecting water quality, preserving critical natural features and accommodating wildlife whose survival depends upon water features and conservation corridors. For example, some studies suggest that riparian buffers of 150 feet may be required for certain Michigan threatened species to successfully move between larger conservation areas and maintain healthy breeding populations. Therefore, it is a policy of the Village to educate, outreach and otherwise assist riparian landowners in the implantation of additional voluntary stormwater best management practices.

Stormwater storage facilities which protect water quality and prevent adverse flooding on-site and off-site shall be required for all sites. In order to improve the quality of stormwater runoff and reduce the discharge of sediment into wetlands, watercourses, roadways, structures and other property within, and downstream of the Village of Vicksburg, the following techniques in Subsection B(1) through (6) and standards in Subsection B(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 which drain completely after a storm event (e.g., dry basins) but which discharge stormwater to wetlands or constructed basins which trap sediment carried by stormwater runoff.

(4)

Detention basins which hold stormwater 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, at a minimum. Retention basins without a positive outlet shall be designed to hold runoff from a one-hundred-year storm event.

(6)

The banks of detention basins shall not exceed a 1:5 slope unless a fence is constructed.

(7)

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 Kalamazoo County Drain Commissioner.

(8)

Discharge of runoff from commercial and industrial sites which 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 Kalamazoo County Drain Commissioner.

(9)

The use of stormwater management areas and vegetated buffer areas as open space, recreation, and conservation areas shall be encouraged.

(10)

Right of entry; furnishing information. Representatives of the Village, State of Michigan DNR or DEQ, Michigan Department of Transportation, and Kalamazoo County Drain Commission shall have the right to enter at any reasonable time any property served by a stormwater drainage facility for inspections, investigations, or monitoring. 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.

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 which are within a 500-foot distance of any natural lake or pond.

(4)

Wetlands which are within a 100-foot distance of any river or stream.

Discharges from stormwater conveyance facilities shall be routed through swales, vegetated buffer strips, stormwater basins, hydrologically isolated wetlands, and other facilities designed to decrease runoff velocity and volume, allow for natural infiltration, allow suspended solids to settle, and remove pollutants.

If wetlands are proposed for stormwater detention, runoff must be diffused to nonerosive velocities before it reaches the wetlands.

Operation and maintenance. All structural and vegetative best management practices installed as a performance standard for stormwater management shall include a plan for maintaining maximum performance through long-term operation and maintenance (O&M). The plan shall include a schedule for O&M procedures and recordkeeping provisions such as periodic inspections.

Records retention. Inspections and other records pertaining to the O&M of best management practices for stormwater water quality protection shall be maintained by the property owner and retained for a minimum of five years.

No stormwater management plan shall be approved if the Village of Vicksburg Planning Commission finds that the action will or is likely to pollute, impair or destroy air, water or other natural resources or the public trust therein, provided that there is a feasible and prudent alternative consistent with the reasonable requirements of the public health, safety and welfare.