[Adopted as Ch. 50 of the Village Code]
A.
The purpose of this article is to set forth stormwater requirements
and criteria which will prevent and control water pollution and diminish
the threats to public health, safety, welfare, and aquatic life due
to runoff of stormwater from development or redevelopment.
B.
The Village of Allouez recognizes that the preferred method of addressing stormwater management problems and needs is through the preparation of comprehensive stormwater management plans for logical subwatershed areas which are designed to meet the purpose and intent of this article. Accordingly, the standards for on-site stormwater management set forth in § 385-7 do not apply in areas where such plans have been prepared and approved by the Village of Allouez. In those areas for which approved stormwater management plans have been prepared, all land development activities will include best management practices set forth in those approved stormwater management plans. It is the general intent of the Village of Allouez to achieve its purpose through managing long-term construction site erosion and post-construction stormwater discharges from land development activities and providing options for developing stormwater management requirements, including application of generic requirements in this article on a site-by-site basis in areas for which no approved stormwater management plan exists and implementation of best management practices set forth in detailed stormwater management plans approved by the Village.
A.
The Village of Allouez under the authority granted by § 61.354, Wis. Stats., adopts this article. Combined, Chapter 387 of this Code and this article supersede all conflicting and contradictory stormwater management regulations previously enacted under § 61.35, Wis. Stats. Except as specifically provided for in § 61.354, Wis. Stats., § 61.35, Wis. Stats., applies to this article and to any amendments to this article.
B.
The provisions of this article are deemed not to limit any other
lawful regulatory powers of the same governing body.
C.
The Village of Allouez hereby designates the Public Works Director
to administer and enforce the provisions of this article.
D.
The requirements of this article do not preempt more stringent stormwater
management requirements that may be imposed by WPDES stormwater permits
issued by the Department of Natural Resources under § 283.33,
Wis. Stats.
The Village of Allouez finds that uncontrolled stormwater runoff
from land development activity has a significant impact upon water
resources and the health, safety, and general welfare of the community
and diminishes the public enjoyment and use of natural resources.
Specifically, uncontrolled stormwater runoff can:
A.
Degrade physical stream habitat by increasing stream bank erosion,
increasing streambed scour, diminishing groundwater recharge, and
diminishing stream base flows;
B.
Diminish the capacity of lakes and streams to support fish, aquatic
life, and recreational and water supply uses by increasing the export
of nutrients and other urban pollutants;
C.
Alter wetland communities by changing wetland hydrology and by increasing
pollutant loads;
D.
Reduce the quality of groundwater by increasing pollutant loading;
E.
Threaten public health, safety, property, and general welfare by
overtaxing storm sewers, drainageways, and other minor drainage facilities;
F.
Threaten public health, safety, property, and general welfare by
increasing major flood peaks and volumes; and
G.
Undermine floodplain management efforts by increasing the incidence
and levels of flooding.
As used in this article, the following terms shall have the
meanings indicated:
Structural or nonstructural measures, practices, techniques
or devices employed to avoid or minimize soil, sediment or pollutants
carried in runoff to the municipal separate storm sewer system (MS4)
or waters of the state.
A day the Village Hall is routinely and customarily open
for business.
A court-issued order to halt land disturbing construction
activity that is being conducted without the required permit.
A development or sale where multiple separate and distinct
land disturbing construction activities may be taking place at different
times on different schedules but under one plan. A common plan of
development or sale includes, but is not limited to, subdivision plats,
certified survey maps, and other developments.
An area upon which one or more land disturbing construction
activities occur, including areas that are part of a larger common
plan of development or sale.
That storm that produces the highest peak rate of runoff.
To determine the critical duration storm a series of rainfall depths
and durations are run in an iterative process until the highest peak
is found.
A hypothetical discrete rainstorm characterized by a specific
duration, temporal distribution, rainfall intensity, return frequency,
and total depth of rainfall. The TR-55, Type II, twenty-four-hour
design storms for the Village of Allouez are: one-year, 2.2 inches;
two-year, 2.5 inches; five-year, 3.2 inches; ten-year, 3.7 inches;
twenty-five-year, 4.3 inches; fifty-year, 4.8 inches; and one-hundred-year,
5.1 inches.
Residential, commercial, industrial, institutional, or other
land uses and associated roads.
The creation from one or more parcels or building sites of
additional parcels or building sites where such creation occurs at
one time or through the successive partition within a five-year period.
A legal agreement to allow water to flow across a piece of
property. The easement establishes specific requirements for activities
that can and cannot take place in the easement zone.
The process by which the land's surface is worn away
by the action of wind, water, ice or gravity.
A payment of money to the Village of Allouez in place of meeting all or part of the stormwater performance standards required by Chapter 387 of this Code or this article.
A performance bond, maintenance bond, surety bond, irrevocable
letter of credit, or similar guarantees submitted to the Public Works
Director by the responsible party to assure that requirements of this
article are carried out in compliance with the stormwater management
plan.
An area that releases as runoff all or a large portion of
the precipitation that falls on it, except for frozen soil. Rooftops,
sidewalks, driveways, parking lots and streets are examples of areas
that typically are impervious. Gravel surfaces are considered impervious,
unless specifically designed to encourage infiltration.
The entry of precipitation or runoff into or through the
soil.
An agreement with a bank or other institution to pay money
or extend credit to honor the terms of the permit with the Village
of Allouez.
Any man-made alteration of the land surface resulting in
a change in the topography or existing vegetative or nonvegetative
soil cover that may result in runoff and lead to an increase in soil
erosion and movement of sediment into the MS4 or waters of the state.
"Land disturbing construction activity" includes clearing and grubbing,
demolition, excavating, pit trench dewatering, filling and grading
activities, and soil stockpiling.
A town, county, village, or city.
A small channel located within a waterway used to concentrate
flow during small storms. The purpose of a low flow channel is to
maintain adequate water depth for aquatic organisms and needed scour
velocities to prevent sediment buildup.
A legal document that is filed with the Brown County Register
of Deeds as a property deed restriction and which provides for long-term
maintenance of stormwater management and best management practices.
A bond which guarantees that the permit holder will perform
needed maintenance outlined in the permit. The bond protects the Village
against loss due to the inability or refusal of the permit holder
to perform to the conditions of the permit.
A drainage system of open channels and overland flow paths
that carry stormwater during large rainfall events, typically with
greater than a ten-year recurrence interval.
A level of implementing best management practices in order
to achieve a performance standard specified in this article which
takes into account the best available technology, cost-effectiveness
and other competing issues such as human safety and welfare, endangered
and threatened resources, historic properties and geographic features.
MEP allows flexibility in the way to meet the performance standards
and may vary based on the performance standard and site conditions.
Those components of the drainage system designed to carry
small rainstorms. The minor drainage system is typically made up of
roadside ditches and storm sewers.
A practice, technique, or measure to reduce the volume, peak
flow rate, or pollutants in stormwater that does not require the design
or installation of fixed stormwater management facilities.
Located outside the property boundary described in the permit
application.
Located within the property boundary described in the permit
application.
A bond which guarantees that the permit holder will perform
to the terms of the agreement. The bond protects the Village against
loss due to the inability or refusal of the permit holder to perform
to the conditions of the permit.
A performance bond, maintenance bond, surety bond, irrevocable
letter of credit, or similar guarantees submitted to the Public Works
Director by the permit holder to assure that requirements of this
article are carried out in compliance with the stormwater management
plan.
A narrative or measurable number specifying the minimum acceptable
outcome for a facility or practice.
A written authorization made by the Public Works Director
to the applicant to conduct land disturbing construction activity
or to discharge post-construction runoff to the MS4 or waters of the
state.
An area that releases as runoff a small portion of the precipitation
that falls on it. Lawns, gardens, parks, forests or other similar
vegetated areas are examples of surfaces that typically are pervious.
Has the meaning given in § 283.01(13), Wis. Stats.
Has the meaning given in § 281.01(10), Wis. Stats.
A construction site following the completion of land disturbing
construction activity and final site stabilization.
The extent and distribution of land cover types present after
the completion of land disturbing construction activity and final
stabilization.
The extent and distribution of land cover types present before
the initiation of land disturbing construction activity, assuming
that all land uses prior to development activity are managed in an
environmentally sound manner.
Has the meaning given in § NR 140.05(17), Wis.
Adm. Code.
Any entity holding fee title to the property or other person
contracted or obligated by other agreement to implement and maintain
post-construction stormwater BMPs.
Stormwater or precipitation, including rain, snow or ice
melt or similar water, that moves on the land surface via sheet or
channelized flow.
The entire area included in the legal description of the
land on which the land disturbing construction activity occurred.
Any physical characteristic which limits the use of a best
management practice as prescribed in the latest edition of technical
standards identified, developed or disseminated by the Wisconsin Department
of Natural Resources under Subchapter V of Ch. NR 151, Wis. Adm. Code.
An order issued by the Public Works Director which requires
that all construction activity on the site be stopped.
A comprehensive plan designed to reduce the discharge of
pollutants from stormwater after the site has undergone final stabilization
following completion of the construction activity.
Source area practices, conveyance measures, and end-of-pipe
treatment that are designed to control stormwater runoff pollutant
loads, discharge volumes, and peak flow discharge rates.
A guaranty provided by a bonding company to pay the Village
for loss due to the inability or refusal of the permit holder to perform
to the conditions of the permit.
A document that specifies design, predicted performance and
operation and maintenance specifications for a material, device or
method.
The United States Department of Agriculture, Natural Resources
Conservation Service (previously Soil Conservation Service), Urban
Hydrology for Small Watersheds, Second Edition, Technical Release
55, June 1986.
A rainfall type curve as established in the United States
Department of Agriculture, Soil Conservation Service, Technical Paper
149, published 1973. The Type II curve is applicable to all of Wisconsin
and represents the most intense storm pattern.
Has the meaning given in § 281.01(18), Wis. Stats.
A permit issued by the Wisconsin Department of Natural Resources
under § 283.33, Wis. Stats., that authorizes the point source
discharge of stormwater to waters of the state.
A.
Applicability.
(1)
Where not otherwise limited by law, this article applies to all post-construction sites, unless the site is otherwise exempt under Subsection A(2).
(2)
A post-construction site that meets any of the criteria in this subsection
is exempt from the requirements of this article:
(a)
One- and two-family residential dwellings that are not part
of a larger common plan of development or sale and that result in
less than one acre of disturbance.
(3)
Notwithstanding the applicability requirements in Subsection A(1), this article applies to post-construction sites of any size that, in the opinion of the Public Works Director, are likely to result in runoff that exceeds the safe capacity of the existing drainage facilities or receiving body of water, that may cause excessive site erosion, that increases water pollution by scouring or the transportation of particulate matter, or that endangers property or public safety.
B.
Jurisdiction. This article applies to post-construction sites within
the boundaries and jurisdiction of the Village of Allouez.
C.
Exclusions. This article is not applicable to activities conducted
by a state agency, as defined under § 227.01(1), Wis. Stats.,
but also including the office of District Attorney, which is subject
to the state plan promulgated or a memorandum of understanding entered
into under § 281.33(2), Wis. Stats.
Unless the Public Works Director gives prior authorization, the following methods shall be used for designing best management practices and drainage systems to meet the requirements of Chapter 387 of this Code and this article:
A.
All hydrologic and hydraulic design calculations for stormwater storage
or detention facilities shall be based on the principles of the SCS
curve method document titled "Urban Hydrology for Small Watersheds"
(TR-55) or other methods acceptable to the Public Works Director.
Computer models that may be used include:
B.
For the design of stormwater drainage systems, including storm sewers
or open ditches, either the SCS curve method or the rational method
may be used. The rational method can only be used for watersheds less
than 200 acres in size.
A.
Drainage system requirements. All land development activities subject
to this article shall satisfy the following drainage system requirements:
(1)
A drainage system shall be designed and constructed by the permittee
to provide for proper drainage of the development site and the drainage
area of which it is a part.
(2)
Lots shall be laid out so as to provide positive drainage away from
all buildings, and individual lot drainage shall be coordinated with
the general storm drainage pattern for the area.
(3)
Any stormwater drainage system will be separate and independent of
any sanitary sewer system. Storm sewers, where utilized, shall be
designed in accordance with all governmental regulations, and a copy
of design computations for engineering capacities shall accompany
plans submitted by the petitioner's engineer for the final plat.
(4)
Stormwater drainage systems shall be designed to utilize the natural
drainage and storage capabilities of the site to the fullest extent
practicable. Stormwater drainage systems shall be designed to provide
an economical gravity flow drainage system.
(5)
Stormwater drainage systems shall be designed to utilize the collector
and land access streets as open runoff channels during major storm
events without flooding adjoining building sites. The streets will
be supplementary to the minor stormwater drainage system.
(6)
Bridges and culverts.
(a)
All new and replacement culverts and bridges over waterways
shall be designed so as to accommodate, according to the categories
listed below, the designated flood event without overtopping the related
roadway or railway track:
[1]
Minor and collector streets used or intended to be used primarily
for access to abutting properties: a ten-year recurrence interval
flood discharge.
[2]
Arterial streets and highways, other than freeways and expressways,
used or intended to be used primarily to carry heavy volumes of traffic:
a fifty-year recurrence interval flood discharge.
[3]
Freeway and expressway: a one-hundred-year recurrence interval
flood discharge.
[4]
Railways: a one-hundred-year recurrence interval flood discharge.
(b)
The depth of flow over the top of minor, collector, and arterial
streets and highways shall not exceed six inches during the one-hundred-year
recurrence interval flood discharge.
(c)
Bridges and culverts shall be designed to facilitate fish passage
through elimination of hydraulic drops, maintenance of low flow channels,
and minimization of excess stream enclosures.
(7)
Street drainage. All streets shall be provided with an adequate storm
drainage system. The street storm drainage system shall serve as the
minor drainage system and shall be designed to carry street, adjacent
land and building stormwater drainage. Stormwater shall not be permitted
to be run into the sanitary sewer system within the proposed subdivision.
In order to provide an acceptable level of access to property and
traffic service, the drainage system shall be designed to provide
two clear lanes of moving traffic on arterial streets and one ten-foot
lane for moving traffic on collector and land access streets during
the ten-year critical duration storm. Temporary accumulations of storm
runoff from ponding or flowing water, in or near minor system components,
shall be permitted during events beyond the ten-year, provided that
such accumulations do not encroach on any traffic lane of any collector
or arterial street and are not more than six inches deep as measured
at the center line of any local street.
(8)
Off-street drainage. The design of the off-street major drainage system shall include the entire watershed affecting the land division and shall be extended to a watercourse or ditch adequate to receive the storm drainage. When the drainage system is outside of the street right-of-way, the developer shall make provisions for providing an easement pursuant to Subsection B of this section to provide for the future maintenance of said system.
(9)
Drainage piping systems. Unless otherwise approved by the Public
Works Director, all drainage piping of 12 inches diameter and greater
in street rights-of-way shall be constructed according to the Village
engineering specifications. Piping materials outside of rights-of-way
shall be subject to approval of the Village.
(10)
Agricultural drains. Agricultural drain tiles which are disturbed
during construction shall be restored, reconnected or connected to
public storm drainage facilities.
(11)
Open channel systems.
(a)
Where open channels are utilized in either the minor or major
drainage system, they shall be designed so as to minimize maintenance
requirements. Drainage easements, in lieu of dedications, shall be
utilized to accommodate open channels provided with adequate access
by the Village for maintenance of drainage capacity. Side slopes shall
not be steeper than a three-to-one slope unless approved by the Public
Works Director.
(b)
Major drainageways should be designed with low flow channels
to maintain increased stream velocity to reduce sedimentation in the
stream channels and accompanying nuisance vegetation.
(12)
Protection of drainage systems. The permittee shall adequately
protect all ditches to the satisfaction of the Village Public Works
Director. Open channels shall be seeded, sodded or riprapped based
upon criteria and considerations contained within technical standards
identified, developed or disseminated by the Wisconsin Department
of Natural Resources under Subchapter V of Ch. NR 151, Wis. Adm. Code.
B.
Drainage easements. Where a land division is traversed by a watercourse,
drainageway, channel or stream:
(1)
There shall be provided a stormwater easement or drainage right-of-way
conforming substantially to the lines of such watercourse and such
further width or construction, or both, as will be adequate for the
purpose and as may be necessary to comply with this section; or
(2)
The watercourse, drainageway, channel or stream may be relocated
in such a manner that the maintenance of adequate drainage will be
assured. When channels are relocated, a stormwater easement or drainage
right-of-way conforming to the lines of the relocated watercourse
and such further width or construction, or both, as will be adequate
for the purpose and as may be necessary to comply with this section
will be provided. For state-designated navigable streams, such relocations
shall only be in accord with a permit issued by the Wisconsin Department
of Natural Resources; or[1]
(3)
Wherever possible, drainage shall be maintained in an easement by
an open channel with vegetated banks and adequate width for maximum
potential volume flow. In all cases, such easements shall be wide
enough to convey the ten-year critical duration storm for the minor
drainage system and the one-hundred-year critical duration storm for
the major drainage system. The drainage easement under all circumstances
shall not be less than 30 feet in width.
C.
Stormwater discharge quantity and quality. Unless otherwise provided for in this article, all land development activities subject to this article shall establish on-site best management practices in accordance with Chapter 200, Construction Site Erosion Control, and Chapter 387, Post-Construction Stormwater Management, of this Code.
D.
Exceptions. The requirements for on-site best management practices established in Subsection C are not applicable in areas which are determined by the Public Works Director to be covered by an approved erosion control plan and/or stormwater management plan which was developed and approved as an alternative planning approach to carrying out on-site measures consistent with the purpose and intent of this article. In such cases, the recommendations of the approved erosion control plan and/or stormwater management plan shall be applied either through the installation of best management practices recommended to be included on the development site being considered and/or through the payment of a fee as set forth in Subsection E. These minimum requirements may also be waived in whole or in part by the Village Board upon written request of the applicant, provided that at least one of the following conditions applies:
(1)
Provisions are made to manage stormwater by an off-site facility.
This requires that the off-site facility is in place and is designed
and adequately sized to provide a level of stormwater control that
is equal to or greater than that which would be afforded by application
of the standards of this article.
(2)
The Public Works Director finds that meeting the minimum on-site
management requirements is infeasible due to space or site restrictions.
E.
Fee in lieu of on-site best management practices. Where the Village waives all or part of the minimum on-site stormwater management requirements under Subsection C, or where the waiver is based on the provision of adequate stormwater facilities provided by the Village of Allouez downstream of the proposed development, the applicant shall be required to pay a fee in an amount determined in negotiation with the Village Board. In setting the fee for land development projects, the Village Board shall consider an equitable distribution of the cost of land, engineering design, construction, and maintenance as set forth in § 66.0617, Wis. Stats.
F.
General considerations for on-site and off-site best management practices.
The following considerations shall be observed in managing stormwater
runoff:
(1)
Natural topography and land cover features such as natural swales,
natural stream channels, floodplain, natural depressions, native soil
infiltrating capacity, and natural groundwater recharge areas shall
be preserved and used, to the extent possible, to meet the requirements
of this section.
(2)
Emergency overland flow for all stormwater facilities shall be considered
to prevent exceeding the capacity of downstream drainage facilities
and prevent endangerment of downstream property or public safety.
