[Ord. 229, 2005]
The Village of Darien under the authority granted by Section
61.354, for Villages, Wis. Stats., adopts the ordinance codified in
this chapter. This chapter supersedes all provisions of an ordinance
previously enacted under Section. 61.35, Wis. Stats. that relate to
storm water management regulations. Except as otherwise specified
in Section 61.354, Wis. Stats. Section 61.35, Wis. Stats., applies
to this chapter and to any amendments to this chapter.
A.
The provisions of this chapter are deemed not to limit any other
lawful regulatory powers of the same governing body.
B.
The Village Board designates the Village of Darien to administer
and enforce the provisions of this chapter.
C.
The requirements of this chapter do not preempt more stringent storm
water management requirements that may be imposed by any of the following:
1.
Wisconsin Department of Natural Resources administrative rules, permits
or approvals including those authorized under Sections 281.16 and
283.33, Wis. Stats.;
2.
Targeted nonagricultural performance standards promulgated in rules
by the Wisconsin Department of Natural Resources under Section NR
151.004, Wis. Adm. Code;
3.
Village of Darien approved or adopted storm water management plans
for specific areas or watersheds.
[Ord. 229, 2005]
The Village Board finds that uncontrolled, post-construction
runoff 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
post-construction runoff can:
A.
Degrade physical stream habitat by increasing stream bank erosion,
increasing streambed scour, diminishing groundwater recharge, diminishing
stream base flows and increasing stream temperature;
B.
Diminish the capacity of lakes and streams to support fish, aquatic
life, recreational and water supply uses by increasing pollutant loading
of sediment, suspended solids, nutrients, heavy metals, bacteria,
pathogens 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, drainage ways, and other minor drainage facilities;
F.
Threaten public health, safety, property and general welfare by increasing
major flood peaks and volumes;
G.
Undermine floodplain management efforts by increasing the incidence
and levels of flooding.
[Ord. 229, 2005]
A.
Purpose. The general purpose of this chapter is to establish long-term,
post-construction runoff management requirements that will diminish
the threats to public health, safety, welfare, and the aquatic environment.
Specific purposes are to:
1.
Further the maintenance of safe and healthful conditions;
2.
Prevent and control the adverse effects of storm water; prevent and
control soil erosion; prevent and control water pollution; protect
spawning grounds, fish and aquatic life; control building sites, placement
of structures and land uses; preserve ground cover and scenic beauty;
and promote sound economic growth;
3.
Control exceedance of the safe capacity of existing drainage facilities
and receiving water bodies; prevent undue channel erosion; control
increases in the scouring and transportation of particulate matter;
and prevent conditions that endanger downstream property.
B.
Intent. It is the intent of the Village Board that this chapter regulates
post-construction storm water discharges to waters of the state. This
chapter may be applied on a site-by-site basis. The Village Board
recognizes, however, that the preferred method of achieving the storm
water performance standards set forth in this chapter is through the
preparation and implementation of comprehensive, systems-level storm
water management plans that cover hydrologic units, such as watersheds,
on a municipal and regional scale. Such plans may prescribe regional
storm water devices, practices or systems, any of which may be designed
to treat runoff from more than one site prior to discharge to waters
of the state. Where such plans are in conformance with the performance
standards developed under Section 281.16, Wis. Stats., for regional
storm water management measures and have been approved by the Village
Board, it is the intent of this chapter that the approved plan be
used to identify post-construction management measures acceptable
for the community.
[Ord. 229, 2005]
A.
Applicability.
1.
Where not otherwise limited by law, this chapter applies after final stabilization to a site of land disturbing construction activity meeting any of the criteria in this section, unless the site is otherwise exempt under Subsection (A)(2) of this section.
a.
A post-development construction site that has one or more acres
of land disturbing construction activity.
2.
A site that meets any of the criteria in this section is exempt from
the requirements of this chapter.
a.
A redevelopment post-construction site with no increase in exposed
impervious surface area.
b.
A post-construction site with less than 10% connected imperviousness
based on complete development of the post-construction site, provided
the cumulative area of all parking lots and rooftops is less than
one acre.
c.
Nonpoint discharges from agricultural facilities and practices.
d.
Nonpoint discharges from silviculture activities.
e.
Routine maintenance for project sites under five acres of land
disturbance if performed to maintain the original line and grade,
hydraulic capacity or original purpose of the facility.
f.
Underground utility construction such as water, sewer and fiber
optic lines. This exemption does not apply to the construction of
any above ground structures associated with utility construction.
3.
Notwithstanding the applicability requirements in Subsection (A)(1)(a)
of this section, this section applies to post-construction sites of
any size that, in the opinion of the Village of Darien, is likely
to result in runoff that exceeds the safe capacity of the existing
drainage facilities or receiving body of water, that causes undue
channel erosion, that increases water pollution by scouring or the
transportation of particulate matter or that endangers property or
public safety.
B.
Jurisdiction. This chapter applies to post-construction sites within
the boundaries and jurisdiction of the Village of Darien.
C.
Exclusions. This chapter is not applicable to activities conducted
by a state agency, as defined under Section 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 Section 281.33(2), Wis. Stats.
[Ord. 229, 2005]
As used in this chapter:
A governmental employee, or a regional planning commission
empowered under Section 61.354, Wis. Stats, that is designated by
the Village Board to administer this ordinance.
Has the meaning given in Section 281.16, Wis. Stats.
A calendar year of precipitation, excluding snow, which is
considered typical.
Structural or nonstructural measures, practices, techniques
or devices employed to avoid or minimize sediment or pollutants carried
in runoff to waters of the state.
A day the offices of 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 system for conveying both sanitary sewage and storm water
runoff.
An impervious surface that is directly connected to a separate
storm sewer or water of the state via an impervious flow path.
A hypothetical discrete rainstorm characterized by a specific
duration, temporal distribution, rainfall intensity, return frequency,
and total depth of rainfall.
Residential, commercial, industrial, or institutional land
uses and associated roads.
The creation from one parcel of two or more parcels or building
sites of one or fewer acres each in area where such creation occurs
at one time or through the successive partition within a five-year
period.
The area of the infiltration system that is used to infiltrate
runoff and does not include the area used for site access, berms or
pretreatment.
The process by which the land's surface is worn away
by the action of the wind, water, ice or gravity.
Waters listed in Section NR 102.11, Wis. Adm. Code.
The unincorporated area within three miles of the corporate
limits of a first, second or third class city, or within 1 1/2
miles of a fourth class city or Village.
That all land disturbing construction activities at the construction
site have been completed and that a uniform, perennial, vegetative
cover has been established, with a density of at least 70% of the
cover, for the unpaved areas and areas not covered by permanent structures,
or employment of equivalent permanent stabilization measures.
A performance bond, maintenance bond, surety bond, irrevocable
letter of credit, or similar guarantees submitted to the Village of
Darien by the responsible party to assure that requirements of this
chapter are carried out in compliance with the storm water management
plan.
Village, county board of trustees, city council, Village
Board or Village council.
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.
An undeveloped area of land located within existing development.
The entry of precipitation or runoff into or through the
soil.
A device or practice such as a basin, trench, rain garden
or swale designed specifically to encourage infiltration, but does
not include natural infiltration in pervious surfaces such as lawns,
redirecting of rooftop downspouts onto lawns or minimal infiltration
from practices, such as swales or road side channels designed for
conveyance and pollutant removal only.
An area or surficial geologic feature subject to bedrock
dissolution so that it is likely to provide a conduit to groundwater,
and may include caves, enlarged fractures, mine features, exposed
bedrock surfaces, sinkholes, springs, seeps or swallets.
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 waters of the state. Land disturbing
construction activity includes clearing and grubbing, demolition,
excavating, pit trench dewatering, filling and grading activities.
A legal document that provides for long-term maintenance
of storm water management practices.
A level of implementing best management practices in order
to achieve a performance standard specified in this chapter 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.
Development resulting from the conversion of previously undeveloped
land or agricultural land uses.
Located outside the property boundary described in the permit
application.
Located within the property boundary described in the permit
application.
Has the meaning given in Section NR 115.03(6), Wis. Adm.
Code.
Waters listed in Section NR 102.10, Wis. Adm. Code.
The percentage of a given sample of soil, which passes through
a number 200 sieve.
A narrative or measurable number specifying the minimum acceptable
outcome for a facility or practice.
A written authorization made by the Village of Darien to
the applicant to conduct land disturbing construction activity or
to discharge post-construction runoff to waters of the state.
A sum of money paid to the Village of Darien by the permit
applicant for the purpose of recouping the expenses incurred by the
authority in administering the permit.
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 Section 283.01(13), Wis. Stats.
Has the meaning given in Section 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 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 Section NR 140.05(17), Wis. Adm.
Code.
Areas where development is replacing older development.
Any entity holding fee title to the property or other person
contracted or obligated by other agreement to implement and maintain
post-construction storm water BMPs.
Storm water or precipitation including rain, snow or ice
melt or similar water that moves on the land surface via sheet or
channelized flow.
A conveyance or system of conveyances including roads with
drainage systems, streets, catch basins, curbs, gutter, ditches, constructed
channels or storm drains, which meets all of the following criteria:
The entire area included in the legal description of the
land on which the land disturbing construction activity occurred.
An order issued by the Village of Darien which requires that
all construction activity on the site be stopped.
A comprehensive plan designed to reduce the flow rate, runoff
volume, and discharge of pollutants from storm water after the site
has under gone final stabilization following completion of the construction
activity.
A comprehensive plan designed to reduce the discharge of
runoff and pollutants from hydrologic units on a regional or municipal
scale.
A document that specifies design, predicted performance and
operation and maintenance specifications for a material, device or
method.
An edge, or point on the landscape, landward from the ordinary
high-water mark of a surface water of the state, where the slope of
the land begins to be less than 12% continually for at least 50 feet.
If the slope of the land is 12% or less continually for the initial
50 feet, landward from the ordinary high-water mark, the top of the
channel is the ordinary high-water mark.
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." Rainfall depths shall be consistent with Technical
Report 40, "Rainfall Frequency in the Southeastern Wisconsin Region,"
SEWRPC, April, 2000.
Has the meaning given in Section 281.01(18), Wis. Stats.
[Ord. 229, 2005]
The following methods shall be used in designing and meeting
the performance standards for the storm water management plan:
A.
Technical standards identified, developed or disseminated by the
Wisconsin Department of Natural Resources under subchapter V of Chapter
NR 151, Wis. Adm. Code;
B.
Where technical standards have not been identified or developed by
the Wisconsin Department of Natural Resources, other technical standards
may be used provided that the methods have been approved by the Village
of Darien;
C.
Technical engineering standards administered and/or approved by the
Village of Darien;
D.
Technical standards described in "The Wisconsin Storm Water Manual,"
WDNR for Wet Detention Basins;
E.
In this chapter, the following year and location has been selected
as average annual rainfall: Milwaukee 1969 (Mar. 28-Dec. 6).
[Ord. 229, 2005]
A.
Responsible Party. The responsible party shall implement a post-construction
storm water management plan that incorporates the requirements of
this section.
B.
Plan. A written storm water management plan in accordance with Section 17.23.090 of this chapter shall be developed and implemented for each post-construction site.
C.
Requirements. The plan required under Subsection B of this section shall include the following:
1.
Total Suspended Solids. BMPs shall be designed, installed and maintained
to control total suspended solids carried in runoff from the post-construction
site as follows:
a.
For new development, by design, reduce to the maximum extent
practicable, the total suspended solids load by 80%, based on the
average annual rainfall, as compared to no runoff management controls.
No person shall be required to exceed an 80% total suspended solids
reduction to meet the requirements of this subdivision.
b.
For redevelopment, by design, reduce to the maximum extent practicable,
the total suspended solids load by 40%, based on the average annual
rainfall, as compared to no runoff management controls. No person
shall be required to exceed a 40% total suspended solids reduction
to meet the requirements of this subsection.
c.
For in-fill development less than five acres that occurs within
10 years after October 1, 2002, by design, reduce to the maximum extent
practicable, the total suspended solids load by 40%, based on an average
annual rainfall, as compared to no runoff management controls. No
person shall be required to exceed a 40% total suspended solids reduction
to meet the requirements of this subsection.
d.
For in-fill development that occurs 10 or more years after October
1, 2002, by design, reduce to the maximum extent practicable, the
total suspended solids load by 80%, based on an average annual rainfall,
as compared to no runoff management controls. No person shall be required
to exceed an 80% total suspended solids reduction to meet the requirements
of this subsection.
e.
Notwithstanding Subsections (C)(1)a) — (d) of this section,
if the design cannot achieve the applicable total suspended solids
reduction specified, the storm water management plan shall include
a written and site-specific explanation why that level of reduction
is not attained and the total suspended solids load shall be reduced
to the maximum extent practicable.
2.
Peak Discharge.
a.
By design, storm water management practices shall be employed
to reduce the twenty-four-hour, post-development runoff rate to the
twenty-four-hour, pre-development runoff rate for all storm events.
Pre-development conditions shall assume "good hydrologic conditions"
for appropriate land covers as identified in TR-55 or an equivalent
methodology. The meaning of "hydrologic soil group" and "runoff curve
number" are as determined in TR-55. However, when pre-development
land cover is cropland, rather than using TR-55 values for cropland,
the runoff curve numbers in Table 1 shall be used.
|
Table 1
Maximum Predevelopment Runoff Curve Numbers for Cropland
Areas
| |||||
|---|---|---|---|---|---|
|
Hydrologic Soil Group
|
A
|
B
|
C
|
D
| |
|
Runoff Curve Number
|
56
|
70
|
79
|
83
| |
b.
By design, storm water management practices shall be employed
to meet peak discharge requirements of Village adopted storm water
management plans for specific areas or watersheds where applicable.
3.
Infiltration. BMPs shall be designed, installed, and maintained to
infiltrate runoff to the maximum extent practicable in accordance
with the following, except as provided in Subsections (C)(3)(e) through
(g) of this section.
a.
For residential developments one of the following shall be met:
i.
Infiltrate sufficient runoff volume so that the post-development
infiltration volume shall be at least 90% of the pre-development infiltration
volume, based on an average annual rainfall. However, when designing
appropriate infiltration systems to meet this requirement, no more
than 1% of the project site is required as an effective infiltration
area.
ii.
Infiltrate 25% of the post-development runoff from the two-year,
twenty-four-hour design storm with a type II distribution. Separate
curve numbers for pervious and impervious surfaces shall be used to
calculate runoff volumes and not composite curve numbers as defined
in TR-55. However, when designing appropriate infiltration systems
to meet this requirement, no more than 1% of the project site is required
as an effective infiltration area.
b.
For nonresidential development, including commercial, industrial
and institutional development, one of the following shall be met:
i.
Infiltrate sufficient runoff volume so that the post-development
infiltration volume shall be at least 60% of the pre-development infiltration
volume, based on an average annual rainfall. However, when designing
appropriate infiltration systems to meet this requirement, no more
than 2% of the project site is required as an effective infiltration
area.
ii.
Infiltrate 10% of the runoff from the two-year, twenty-four-hour
design storm with a type II distribution. Separate curve numbers for
pervious and impervious surfaces shall be used to calculate runoff
volumes, and not composite curve numbers as defined in TR-55. However,
when designing appropriate infiltration systems to meet this requirement,
no more than 2% of the project site is required as an effective infiltration
area.
d.
Before infiltrating runoff, pretreatment shall be required for
parking lot runoff and for runoff from new road construction in commercial,
industrial and institutional areas that will enter an infiltration
system. The pretreatment shall be designed to protect the infiltration
system from clogging prior to scheduled maintenance and to protect
groundwater quality in accordance with Subsection (C)(3)(g) of this
section. Pretreatment options may include, but are not limited to,
oil/grease separation, sedimentation, biofiltration, filtration, swales
or filter strips.
e.
Exclusions. The runoff from the following areas is prohibited
from meeting the requirements of this section:
i.
Areas associated with tier one industrial facilities identified
in Section NR 216.21(2)(a), Wis. Adm. Code, including storage, loading,
rooftop and parking;
ii.
Storage and loading areas of tier two industrial facilities
identified in Section NR 216.21(2)(b), Wis. Adm. Code;
iii.
Fueling and vehicle maintenance areas;
iv.
Areas within 1,000 feet up-gradient or within 100 feet downgradient
of karst features;
v.
Areas with less than three feet separation distance from the
bottom of the infiltration system to the elevation of seasonal high
groundwater or the top of bedrock, except this subsection does not
prohibit infiltration of roof runoff;
vi.
Areas with runoff from industrial, commercial and institutional
parking lots and roads and residential arterial roads with less than
five feet separation distance from the bottom of the infiltration
system to the elevation of seasonal high groundwater or the top of
bedrock;
vii.
Areas within 400 feet of a community water system well as specified
in Section NR 811.16(4), Wis. Adm. Code, or within 100 feet of a private
well as specified in Section NR 812.08(4), Wis. Adm. Code, for runoff
infiltrated from commercial, industrial and institutional land uses
or regional devices for residential development;
viii.
Areas where contaminants of concern, as defined
in Section NR 720.03(2), Wis. Adm. Code are present in the soil through
which infiltration will occur;
ix.
Any area where the soil does not exhibit one of the following
soil characteristics between the bottom of the infiltration system
and the seasonal high groundwater and top of bedrock; at least a three-foot
soil layer with 20% fines or greater; or at least a five-foot soil
layer with 10% fines or greater. This does not apply where the soil
medium within the infiltration system provides an equivalent level
of protection. This subsection does not prohibit infiltration of roof
runoff.
f.
Exemptions. The following are not required to meet the requirements
of this section:
i.
Areas where the infiltration rate of the soil is less than six-tenths
inches/hour measured at the site;
ii.
Parking areas and access roads less than 5,000 square feet for
commercial and industrial development;
iii.
Redevelopment post-construction sites;
iv.
In-fill development areas less than five acres;
v.
Infiltration areas during periods when the soil on the site
is frozen;
vi.
Roads in commercial, industrial and institutional land uses,
and arterial residential roads.
g.
Infiltration systems designed in accordance with this subsection
shall, to the extent technically and economically feasible, minimize
the level of pollutants infiltrating to groundwater and shall maintain
compliance with the preventative action limit at a point of standards
application in accordance with Chapter NR 140, Wis. Adm. Code. However,
if site specific information indicates that compliance with a preventative
action limit is not achievable, the infiltration BMP may not be installed
or shall be modified to prevent infiltration to the maximum extent
practicable.
i.
Notwithstanding in this section, the discharge from BMPs shall
remain below the enforcement standard at the point of standards application.
4.
Protective Areas. The following are minimum standards for protective
areas; however, Village may impose greater limits based on site specific
information.
a.
"Protective area" means an area of land that commences at the
top of the channel of lakes, streams and rivers, or at the delineated
boundary of wetlands, and that is the greatest of the following widths,
as measured horizontally from the top of the channel or delineated
wetland boundary to the closest impervious surface. However, in this
section, "protective area" does not include any area of land adjacent
to any stream enclosed within a pipe or culvert, such that runoff
cannot enter the enclosure at this location.
i.
For outstanding resource waters and exceptional resource waters,
and for wetlands in areas of special natural resources interest as
specified in Section NR 103.04, 75 feet.
ii.
For perennial and intermittent streams identified on a United
States geological survey seven and one-half-minute series topographic
map, or a county soil survey map, whichever is more current, 50 feet.
iii.
For lakes, 50 feet.
iv.
For highly susceptible wetlands, 50 feet. Highly susceptible
wetlands include the following types: fens, sedge meadows, bogs, low
prairies, conifer swamps, shrub swamps, other forested wetlands, fresh
wet meadows, shallow marshes, deep marshes and seasonally flooded
basins. Wetland boundary delineations shall be made in accordance
with Section NR 103.08(1m). This subsection does not apply to wetlands
that have been completely filled in accordance with all applicable
state and federal regulations. The protective area for wetlands that
have been partially filled in accordance with all applicable state
and federal regulations shall be measured from the wetland boundary
delineation after fill has been placed.
v.
For less susceptible wetlands, 10% of the average wetland width,
but no less than 10 feet nor more than 30 feet. Less susceptible wetlands
include degraded wetlands dominated by invasive species such as reed
canary grass.
vi.
In Subsections (C)(4)(a)(i), (iv) and (v) of this section, determinations
of the extent of the protective area adjacent to wetlands shall be
made on the basis of the sensitivity and runoff susceptibility of
the wetland in accordance with the standards and criteria in Section
NR 103.03.
vii.
For concentrated flow channels with drainage areas greater than
130 acres, 20 feet.
b.
This subsection applies to post-construction sites located within
a protective area, except those areas exempted pursuant to Subsection
(C)(4)(d) of this section.
c.
The following requirements shall be met:
i.
Impervious surfaces shall be kept out of the protective area
to the maximum extent practicable. The storm water management plan
shall contain a written site-specific explanation for any parts of
the protective area that are disturbed during construction.
ii.
Where land disturbing construction activity occurs within a
protective area, and where no impervious surface is present, adequate
sod or self-sustaining vegetative cover of 70% or greater shall be
established and maintained. The adequate sod or self-sustaining vegetative
cover shall be sufficient to provide for bank stability, maintenance
of fish habitat and filtering of pollutants from upslope overland
flow areas under sheet flow conditions. Nonvegetative materials, such
as rock riprap, may be employed on the bank as necessary to prevent
erosion, such as on steep slopes or where high velocity flows occur.
iii.
Best management practices such as filter strips, swales, or
wet detention basins, that are designed to control pollutants from
nonpoint sources may be located in the protective area.
d.
This subsection does not apply to:
i.
Redevelopment post-construction sites, if meeting the protective
area standards is deemed impractical by the Village;
ii.
In-fill development areas less than five acres, if meeting the
protective area standards is deemed impractical by the Village;
iii.
Structures that cross or access surface waters such as boat
landings, bridges and culverts;
iv.
Structures constructed in accordance with Section 59.692(1v),
Wis. Stats.;
v.
Post-construction sites from which runoff does not enter the
protective area's surface water, except to the extent that vegetative
ground cover is necessary to maintain bank stability and is deemed
acceptable to the Village.
5.
Fueling and Vehicle Maintenance Areas. Fueling and vehicle maintenance
areas shall, to the maximum extent practicable, have BMPs designed,
installed and maintained to reduce petroleum within runoff, such that
the runoff that enters waters of the state contains no visible petroleum
sheen.
6.
Swale Treatment for Transportation Facilities.
a.
Applicability. Except as provided in Subsection (C)(6)(b) of
this section, transportation facilities that use swales for runoff
conveyance and pollutant removal meet all of the requirements of this
section, if the swales are designed to the maximum extent practicable
to do all of the following:
i.
Be Vegetated. However, where appropriate, nonvegetative measures
may be employed to prevent erosion or provide for runoff treatment,
such as rock riprap stabilization or check dams.
ii.
Carry runoff through a swale for 200 feet or more in length
that is designed with a flow velocity no greater than 1 1/2 feet
per second for the peak flow generated using either a two-year, twenty-four-hour
design storm or a two-year storm with a duration equal to the time
of concentration as appropriate. If a swale of 200 feet in length
cannot be designed with a flow velocity of 1 1/2 feet per second
or less, then the flow velocity shall be reduced to the maximum extent
practicable.
b.
Exemptions. The Village of Darien may, consistent with water
quality standards, require other provisions of this section be met
on a transportation facility with an average daily travel of vehicles
greater than 2,500 and where the initial surface water of the state
that the runoff directly enters is any of the following:
i.
An outstanding resource water;
ii.
An exceptional resource water;
iii.
Waters listed in Section 303(d) of the Federal Clean Water Act
that are identified as impaired in whole or in part, due to nonpoint
source impacts;
iv.
Waters where targeted performance standards are developed under
Section NR 151.004, Wis. Adm. Code, to meet water quality standards.
7.
Storm Sewers and Culverts.
D.
General Considerations for On-Site and Off-Site Storm Water Management
Measures. The following considerations shall be observed in managing
runoff.
1.
Natural topography and land cover features such as natural swales,
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 routes for all storm water facilities shall
be provided to prevent exceeding the safe capacity of downstream drainage
facilities and prevent endangerment of downstream property or public
safety.
E.
Location and Regional Treatment Option.
1.
All BMPs may be located on-site or off-site as part of a regional
storm water device, practice or system.
2.
Post-construction runoff within a nonnavigable surface water that
flows into a regional BMP, such as a wet detention pond, is not required
to meet the performance standards of this chapter. Post-construction
BMPs may be located in nonnavigable surface waters.
3.
Except as allowed under Subsection (E)(4) of this section, post-construction runoff from new development shall meet the post-construction performance standards prior to entering a navigable surface water.
4.
Post-construction runoff from any development within a navigable
surface water that flows into a BMP is not required to meet the performance
standards of this chapter if:
5.
Runoff from existing development, redevelopment and in-fill areas
shall meet the post-construction performance standards in accordance
with this section.
a.
To the maximum extent practicable, BMPs shall be located to
treat runoff prior to discharge to navigable surface waters.
b.
Post-construction BMPs for such runoff may be located in a navigable
surface water if allowable under all other applicable federal, state
and local regulations such as Chapter NR 103, Wis. Adm. Code and Chapter
30, Wis. Stats.
6.
The discharge of runoff from a BMP, such as a wet detention pond,
or after a series of such BMPs is subject to this chapter.
7.
The Village of Darien may approve off-site management measures provided
that all of the following conditions are met:
a.
The Village of Darien determines that the post-construction
runoff is covered by a storm water management system plan that is
approved by the Village of Darien and that contains management requirements
consistent with the purpose and intent of this chapter.
b.
The off-site facility meets all of the following conditions:
i.
The facility is in place;
ii.
The facility is designed and adequately sized to provide a level
of storm water control equal to or greater than that which would be
afforded by on-site practices meeting the performance standards of
this chapter;
iii.
The facility has a legally obligated entity responsible for
its long-term operation and maintenance.
8.
Where a regional treatment option exists such that the Village of
Darien exempts the applicant from all or part of the minimum on-site
storm water management requirements, the applicant shall be required
to pay a fee in an amount determined in negotiation with the Village
of Darien. In determining the fee for post-construction runoff, the
Village of Darien shall consider an equitable distribution of the
cost for land, engineering design, construction and maintenance of
the regional treatment option.
F.
Alternate Requirements. The Village of Darien may establish storm
water management requirements more stringent than those set forth
in this section if the Village of Darien determines that an added
level of protection is needed to protect sensitive resources.
[Ord. 229, 2005]
A.
Permit Required. No responsible party may undertake a land disturbing
construction activity without receiving a post-construction runoff
permit from the Village of Darien prior to commencing the proposed
activity.
B.
Permit Application and Fees. Unless specifically excluded by this
section, any responsible party desiring a permit shall submit to the
Village of Darien a permit application made on a form provided by
the Village of Darien for that purpose.
1.
Unless otherwise excepted by this section, a permit application must
be accompanied by a storm water management plan, a maintenance agreement
and a non-refundable permit administration fee.
2.
The storm water management plan shall be prepared to meet the requirements of Sections 17.23.070 and 17.23.090, the maintenance agreement shall be prepared to meet the requirements of Section 17.23.100, the financial guarantee shall meet the requirements of Section 17.23.110, and fees shall be those established by the Village of Darien as set forth in Section 17.23.120.
C.
Review and Approval of Permit Application. The Village of Darien
shall review any permit application that is submitted with a storm
water management plan, maintenance agreement, and the required fee.
The following approval procedure shall be used:
1.
Within 20 business days of the receipt of a complete permit application, including all items as required by Subsection B of this section, the Village of Darien shall inform the applicant whether the application, plan and maintenance agreement are approved or disapproved based on the requirements of this chapter;
2.
If the storm water permit application, plan and maintenance agreement
are approved, or if an agreed upon payment of fees in lieu of storm
water management practices is made, the Village of Darien shall issue
the permit;
3.
If the storm water permit application, plan or maintenance agreement
is disapproved, the Village of Darien shall detail in writing the
reasons for disapproval;
4.
The Village of Darien may request additional information from the
applicant. If additional information is submitted, the Village of
Darien shall have 20 business days from the date the additional information
is received to inform the applicant that the plan and maintenance
agreement are either approved or disapproved;
5.
Failure by the Village of Darien to inform the permit applicant of
a decision within 30 business days of a required submittal shall be
deemed to mean approval of the submittal and the applicant may proceed
as if a permit had been issued.
D.
Permit Requirements. All permits issued under this section shall be subject to the following conditions, and holders of permits issued under this section shall be deemed to have accepted these conditions. The Village of Darien may suspend or revoke a permit for violation of a permit condition, following written notification of the responsible party. An action by the Village of Darien to suspend or revoke this permit may be appealed in accordance with Section 17.23.140 of this chapter.
1.
Compliance with this permit does not relieve the responsible party
of the responsibility to comply with other applicable federal, state,
and local laws and regulations.
2.
The responsible party shall design and install all structural and
nonstructural storm water management measures in accordance with the
approved storm water management plan and this permit.
3.
The responsible party shall notify the Village of Darien at least five business days before commencing any work in conjunction with the storm water management plan, and within five business days upon completion of the storm water management practices. If required as a special condition under Subsection E of this section, the responsible party shall make additional notification according to a schedule set forth by the Village of Darien so that practice installations can be inspected during construction.
4.
Practice installations required as part of this chapter shall be
certified "as built" by a licensed professional engineer. Completed
storm water management practices must pass a final inspection by the
Village of Darien or its designee to determine if they are in accordance
with the approved storm water management plan and ordinance. The Village
of Darien or its designee shall notify the responsible party in writing
of any changes required in such practices to bring them into compliance
with the conditions of this permit.
5.
The responsible party shall notify the Village of Darien of any significant
modifications it intends to make to an approved storm water management
plan. The Village of Darien may require that the proposed modifications
be submitted for approval prior to incorporation into the storm water
management plan and execution by the responsible party.
6.
The responsible party shall maintain all storm water management practices
in accordance with the storm water management plan until the practices
either become the responsibility of the Village of Darien, or are
transferred to subsequent private owners as specified in the approved
maintenance agreement.
7.
If the responsible party fails to maintain all storm water management practices, the Village of Darien may perform any work or operations necessary to bring storm water management measures into conformance with the approved storm water management plan, and make a special assessment or charge against the property as authorized under sub-chapter VII of Chapter 66, Wis. Stats., or charge such costs against the financial guarantee posted under Section 17.23.110 of this chapter.
8.
If so directed by the Village of Darien, the responsible party shall
repair at the responsible party's own expense all damage to adjoining
municipal facilities and drainage ways caused by runoff, where such
damage is caused by activities that are not in compliance with the
approved storm water management plan.
9.
The responsible party shall permit property access to the Village
of Darien or its designee for the purpose of inspecting the property
for compliance with the approved storm water management plan and this
permit.
10.
Where site development or redevelopment involves changes in
direction, increases in peak rate and/or total volume of runoff from
a site, the Village of Darien may require the responsible party to
make appropriate legal arrangements with affected property owners
concerning the prevention of endangerment to property or public safety.
[Ord. 229, 2005]
A.
Plan Requirements. The storm water management plan required under Section 17.23.080(B) of this chapter shall contain at a minimum the following information:
1.
Name, address, and telephone number for the following or their designees:
landowner; developer; project engineer for practice design and certification;
person(s) responsible for installation of storm water management practices;
and person(s) responsible for maintenance of storm water management
practices prior to the transfer, if any, of maintenance responsibility
to another party.
2.
A proper legal description of the property proposed to be developed,
referenced to the U.S. Public Land Survey system or to block and lot
numbers within a recorded land subdivision plat.
3.
Pre-development site conditions, including:
a.
One or more site maps at a scale of not less than one inch equals
100 feet. The site maps shall show the following: site location and
legal property description; predominant soil types and hydrologic
soil groups; existing cover type and condition; topographic contours
of the site at a scale not to exceed 100 feet; topography and drainage
network including enough of the contiguous properties to show runoff
patterns onto, through, and from the site; watercourses that may affect
or be affected by runoff from the site; flow path and direction for
all storm water conveyance sections; watershed boundaries used in
hydrology determinations to show compliance with performance standards;
lakes, streams, wetlands, channels, ditches, and other watercourses
on and immediately adjacent to the site; limits of the one-hundred-year
floodplain; location of wells and well head protection areas covering
the project area and delineated pursuant to Section NR 811.16, Wis.
Adm. Code.
b.
Hydrology and pollutant loading computations as needed to show
compliance with performance standards. All major assumptions used
in developing input parameters shall be clearly stated. The geographic
areas used in making the calculations shall be clearly cross-referenced
to the required map(s).
4.
Post-development site conditions, including:
a.
Explanation of the provisions to preserve and use natural topography
and land cover features to minimize changes in peak flow runoff rates
and volumes to surface waters and wetlands.
b.
Explanation of any restrictions on storm water management measures
in the development area imposed by well head protection plans and
ordinances.
c.
One or more site maps at a scale of not less than one inch equals
100 feet showing the following: post-construction pervious areas including
vegetative cover type and condition; impervious surfaces including
all buildings, structures, and pavement; post-construction topographic
contours of the site at a scale not to exceed 100 feet; post-construction
drainage network including enough of the contiguous properties to
show runoff patterns onto, through, and from the site; locations and
dimensions of drainage easements; locations of maintenance easements
specified in the maintenance agreement; flow path and direction for
all storm water conveyance sections; location and type of all storm
water management conveyance and treatment practices, including the
on-site and off-site tributary drainage area; location and type of
conveyance system that will carry runoff from the drainage and treatment
practices to the nearest adequate outlet such as a curbed street,
storm drain, or natural drainage way; watershed boundaries used in
hydrology and pollutant loading calculations and any changes to lakes,
streams, wetlands, channels, ditches, and other watercourses on and
immediately adjacent to the site.
d.
Hydrology and pollutant loading computations as needed to show
compliance with performance standards. The computations shall be made
for each discharge point in the development, and the geographic areas
used in making the calculations shall be clearly cross-referenced
to the required map(s).
e.
Results of investigations of soils and groundwater required
for the placement and design of storm water management measures. Detailed
drawings including cross-sections and profiles of all permanent storm
water conveyance and treatment practices.
5.
Construction specifications, description and installation schedule for the storm water management practices needed to meet the performance standards in Section 17.23.070 of this chapter.
6.
A maintenance plan developed for the life of each storm water management
practice including the required maintenance activities and maintenance
activity schedule.
7.
Cost estimates for the construction, operation, and maintenance of
each storm water management practice.
8.
Typed written narrative for BMP design(s) including a description
design procedures, software used and computer model schematics, flow
rates, design results, and any relative information or assumptions
used for the design.
9.
Other information requested in writing by the Village of Darien to
determine compliance of the proposed storm water management measures
with the provisions of this chapter.
10.
All site investigations, plans, designs, computations, and drawings
shall be certified by a licensed Wisconsin professional engineer to
be prepared in accordance with accepted engineering practice and requirements
of this chapter.
B.
Alternate Requirements. The Village of Darien may prescribe alternative submittal requirements for applicants seeking an exemption to on-site storm water management performance standards under Section 17.23.070(E) of this chapter.
[Ord. 229, 2005]
A.
Maintenance Agreement Required. The maintenance agreement required under Section 17.23.080(B) of this chapter for storm water management practices shall be an agreement between the Village of Darien and the responsible party to provide for maintenance of storm water practices beyond the duration period of this permit. The maintenance agreement shall be filed with the county register of deeds as a property deed restriction so that it is binding upon all subsequent owners of the land served by the storm water management practices.
B.
Agreement Provisions. The maintenance agreement shall contain the following information and provisions and be consistent with the maintenance plan required by Section 17.23.090(A)(6) of this chapter:
1.
Identification of the storm water facilities and designation of the
drainage area served by the facilities.
2.
A schedule for regular maintenance of each aspect of the storm water management system consistent with the storm water management plan required under Section 17.23.080(B) of this chapter.
3.
Identification of the responsible party(s), organization or city, county, or Village responsible for long term inspection and maintenance of the storm water management practices identified in the storm water management plan required under Section 17.23.080(B) of this chapter.
4.
Requirement that the responsible party(s), organization or city, county, or Village shall maintain storm water management practices in accordance with the schedule included in Subsection (B)(2) of this section.
5.
Authorization for the Village of Darien to access the property to
conduct inspections of storm water management practices as necessary
to ascertain that the practices are being maintained and operated
in accordance with the agreement.
6.
Agreement that the party designated under Subsection (B)(3) of this section, as responsible for long term inspection and maintenance of the storm water management practices, if notified by the Village of Darien of maintenance problems which require correction, undertake corrective within a reasonable time frame as set by the Village of Darien.
7.
Authorization of the Village of Darien to perform the corrected actions identified in the Village notification under Subsection (B)(6) of this section, if the responsible party designated under Subsection (B)(3) of this section does not make the required corrections in the specified time period. The Village of Darien shall enter the amount due on the tax rolls and collect the money as a special charge against the property pursuant to subchapter VII of Chapter 66, Wis. Stats.
[Ord. 229, 2005]
A.
Establishment of the Guarantee. The Village of Darien may require
the submittal of a financial guarantee, the form and type of which
shall be acceptable to the Village of Darien. The financial guarantee
shall be in an amount determined by the Village of Darien to be the
estimated cost of construction and the estimated cost of maintenance
of the storm water management practices during the period which the
designated party in the maintenance agreement has maintenance responsibility.
The financial guarantee shall give the Village of Darien the authorization
to use the funds to complete the storm water management practices,
or restore the project site as deemed fit by the town, if the responsible
party defaults or does not properly implement the approved storm water
management plan, upon written notice to the responsible party by the
administering authority that the requirements of this chapter have
not been met.
B.
Conditions for Release. Conditions for the release of the financial
guarantee are as follows:
1.
The Village of Darien shall release the portion of the financial
guarantee established under this section, less any costs incurred
by the Village of Darien to complete installation of practices, upon
submission of "as built plans" by a licensed professional engineer.
The Village of Darien may make provisions for a partial pro-rata release
of the financial guarantee based on the completion of various development
stages.
2.
The Village of Darien shall release the portion of the financial
guarantee established under this section to assure maintenance of
storm water practices, less any costs incurred by the Village of Darien,
at such time that the responsibility for practice maintenance is passed
on to another entity via an approved maintenance agreement.
[Ord. 229, 2005]
The fees referred to in other sections of this chapter shall
be established by the Village of Darien and may from time to time
be modified by resolution. A schedule of the fees established by the
Village of Darien shall be available for review in the Village hall.
[Ord. 229, 2005]
A.
Any land disturbing construction activity or post-construction runoff
initiated after the effective date of the ordinance codified in this
chapter by any person, firm, association, or corporation subject to
the ordinance provisions shall be deemed a violation unless conducted
in accordance with the requirements of this chapter.
B.
The Village of Darien shall notify the responsible party by certified
mail of any noncomplying land disturbing construction activity or
post-construction runoff. The notice shall describe the nature of
the violation, remedial actions needed, a schedule of remedial action,
and additional enforcement action which may be taken.
C.
Upon receipt of written notification from the Village of Darien under Subsection B of this section, the responsible party shall correct work that does not comply with the storm water management plan or other provisions of this permit. The responsible party shall make corrections as necessary to meet the specifications and schedule set forth by the Village of Darien in the notice.
D.
If the violations to a permit issued pursuant to this chapter are
likely to result in damage to properties, public facilities, or waters
of the state, the Village of Darien may enter the land and take emergency
actions necessary to prevent such damage. The costs incurred by the
Village of Darien plus interest and legal costs shall be billed to
the responsible party.
E.
The Village of Darien is authorized to post a stop work order on
all land disturbing construction activity that is in violation of
this chapter, or to request the municipal attorney to obtain a cease
and desist order in any court with jurisdiction.
F.
The Village of Darien may revoke a permit issued under this chapter
for noncompliance with ordinance provisions.
G.
Any permit revocation, stop work order, or cease and desist order
shall remain in effect unless retracted by the Village of Darien or
by a court with jurisdiction.
H.
The Village of Darien is authorized to refer any violation of this
chapter, or of a stop work order or cease and desist order issued
pursuant to this chapter, to the municipal attorney for the commencement
of further legal proceedings in any court with jurisdiction.
I.
Any person, firm, association, or corporation who does not comply
with the provisions of this chapter shall be subject to a forfeiture
of not less than $500 or more than $1,000 per offense, together with
the costs of prosecution. Each day that the violation exists shall
constitute a separate offense.
J.
Compliance with the provisions of this chapter may also be enforced
by injunction in any court with jurisdiction. It shall not be necessary
to prosecute for forfeiture or a cease and desist order before resorting
to injunctional proceedings.
K.
When the Village of Darien determines that the holder of a permit issued pursuant to this chapter has failed to follow practices set forth in the storm water management plan, or has failed to comply with schedules set forth in such storm water management plan, the Village of Darien or a party designated by the Village of Darien may enter upon the land and perform the work or other operations necessary to bring the condition of such lands into conformance with requirements of the approved plan. The Village of Darien shall keep a detailed accounting of the costs and expenses of performing this work. These costs and expenses shall be deducted from any financial security posted pursuant to Section 17.23.110 of this chapter. Where such a security has not been established, or where such a security is insufficient to cover these costs, the costs and expenses shall be entered on the tax roll as a special charge against the property and collected with any other taxes levied thereon for the year in which the work is completed.
[Ord. 229, 2005]
A.
Board of Appeals. The Board of Appeals, created pursuant to Section 2.28.020 of the Village of Darien ordinances pursuant to Section 61.354(4)(b), Wis. Stats., shall hear and decide appeals where it is alleged that there is error in any order, decision or determination made by the Village of Darien in administering this chapter. The board shall also use the rules, procedures, duties, and powers authorized by statute in hearing and deciding appeals. Upon appeal, the board may authorize variances from the provisions of this chapter that are not contrary to the public interest, and where owing to special conditions a literal enforcement of the ordinance codified in this chapter will result in unnecessary hardship.
B.
Who May Appeal. Appeals to the Board of Appeals may be taken by any
aggrieved person or by an officer, department, board or bureau of
the Village of Darien affected by any decision of the Village of Darien.
[Ord. 229, 2005]
If any section, clause, provision or portion of this chapter
is judged unconstitutional or invalid by a court of competent jurisdiction,
the remainder of the chapter shall remain in force and not be affected
by such judgment.
[Ord. 229, 2005]
The ordinance codified in this chapter shall be in force and
effect from and after its adoption and publication. The above and
foregoing ordinance was duly adopted by the Village Board of the Village
of Darien on the 16th day of May 2005.
