HomeMy WebLinkAboutItem IV- GreenGreen InfrastructureTACKLING BARRIERS TO
AN AUDIT OF LOCAL CODES
AND ORDINANCES
WISCONSIN SEA GRANT WITH SUPPORT FROM THE NOAA COASTAL STORMS PROGRAM
On the cover: The Brewery, Milwaukee. All photography by Kevin J. Miyazaki.
AN AUDIT OF LOCAL CODES AND ORDINANCES
Green InfrastructureTACKLING BARRIERS TO
WISCONSIN SEA GRANT WITH SUPPORT FROM THE NOAA COASTAL STORMS PROGRAM
TACKLING BARRIERS TO Green Infrastructure
FOREWORD 5
BACKGROUND 6
INTRODUCTION 8
WHAT YOU NEED TO KNOW BEFORE THE AUDIT:
KEY STRATEGIES AND COMMON BARRIERS 11
HOW TO AUDIT LOCAL CODES AND ORDINANCES 17
Community Scoping: Get to Know Your Community 17
Audit Your Community’s Codes and Ordinances 27
Prioritize Recommendations and Develop a Strategy for Adoption 27
WHAT’S THE IMPACT? 30
What’s the Impact: Green Infrastructure Standards for
Parking Lot Landscaping 33
What’s the Impact: Substituting Native Vegetation for Turfgrass 35
What’s the Impact: Reducing Total Impervious Area Associated With Parking 37
What’s the Impact: Allowing and Installing Permeable Alleys 39
What’s the Impact: Landscaping With Native Grasses, Tree Plantings
and Bioretention 41
APPENDIX 1 43
Sample Zoning Definitions for Green Infrastructure Practices 43
APPENDIX 2 45
Green Infrastructure Resources 45
REFERENCES 48
FOOTNOTES 50
ACKNOWLEDGMENTS 51
4 TACKLING BARRIERS TO GREEN INFRASTRUCTURE
Mequon Nature Preserve, restored wetlands
TACKLING BARRIERS TO GREEN INFRASTRUCTURE 5
that run off streets and parking lots. Cleaner
lakes and streams benefit everyone.
Based on the work we have done in dozens
of Wisconsin communities, we partnered
with the University of Wisconsin Sea Grant
Institute to develop this user’s guide to
maximize the benefits of green infrastruc-
ture. With this workbook, you can lead your
community through the process of revising
codes and onto a more sustainable pathway
to stormwater management.
Community participation is key to success.
Changes in zoning should never be consid-
ered without significant and real commu-
nity support. This support will come only
through active citizen participation in the
changes required to realize the greatest
benefits of green infrastructure. By under-
taking a process that identifies the barriers
and opportunities for green infrastructure,
cost-effective stormwater controls can be
developed to meet the community’s goals
and inspire a sense of community pride.
At 1000 Friends of Wisconsin, we believe
developing and implementing a new, more
natural approach to stormwater management
can transform a community’s appearance
and make the community stronger and more
resilient for years to come.
Sincerely,
Steve Hiniker
Retired Executive Director, 1000 Friends of Wisconsin
FOREWORD
Municipal stormwater management
conjures images of gray concrete curb and
gutter covered with prison-like grates. All
too frequently, stormwater management is
relegated to public works departments with
instructions only to keep expenses down.
This workbook illustrates the opportuni-
ties of thinking differently about managing
runoff. It will lead you through the process
of introducing sustainable practices to
manage stormwater. Implementing green
infrastructure practices that use nature
to mimic natural hydrologic processes to
control stormwater can provide multiple
benefits. Water can be managed more
efficiently through the use of native vege-
tation, which can dramatically improve
the aesthetics of a community, leading to
increased property values. Public spaces
naturally landscaped to reduce runoff
become more inviting. Strategic tree
planting to provide natural storage of rain-
water can also provide additional shade that
minimizes urban heat islands — which in
turn reduces the need for air conditioning in
nearby residences. Development that reduces
the need for parking becomes more enjoy-
able for walking.
In addition to providing storage for excess
rainwater in storm events, the best practices
described in this workbook can help improve
water quality. The right choice of vegetation
near a stream or lake can slow down the
flow of water as well as filter out pollutants
6 TACKLING BARRIERS TO GREEN INFRASTRUCTURE
research on the relationship between land
use, ordinances and green infrastructure.
Milwaukee County Environmental Services
provided expertise on green infrastruc-
ture installations and implementation, as
well as lessons learned and best practices.
MMSD, a nationally recognized leader in
green infrastructure, provided extensive data,
local context and priorities established by a
regional green infrastructure plan.
What makes this project unique among
similar audits for green infrastructure? 1000
Friends of Wisconsin recognized the need
for a “no judgment” approach in working
with municipalities to audit, revise and
prioritize codes and ordinances that inhibit
the use of green infrastructure. Barriers to
green infrastructure can vary widely within
the code language, including specific rights,
specific prohibitions, partial limits and
practices mentioned with no guidelines for
implementation or maintenance.
Therefore, solutions to code barriers need to
be customized for the specific municipality
and cannot be satisfactorily addressed by
model ordinances or someone else’s idea
BACKGROUND
This workbook would not have been possible
without the work of 1000 Friends of
Wisconsin who developed and implemented
the green infrastructure municipal code
project throughout southeastern Wisconsin
from 2012-16. With funding support from
the Fund for Lake Michigan, the Wisconsin
Coastal Management Program and the
Milwaukee Metropolitan Sewerage District
(MMSD), 1000 Friends of Wisconsin and
its partners developed a comprehensive
audit process methodology and completed
detailed audits of the codes and ordinances
for the municipalities in the MMSD
service area.
The project team consisted of 1000
Friends of Wisconsin, Milwaukee County
Environmental Services, MMSD, Orion
Planning and Design and the 28 partici-
pating municipalities.
1000 Friends of Wisconsin, with its focus
on livable cities and protection of natural
resources, led the project, bringing its
strengths in communication and partnership
building and engagement. Orion Planning
and Design served as the project’s planning
consultant, bringing years of experience and
expertise in best practices and up-to-date
of how the municipality “should” operate.
Engaging county and municipal zoning
and land use staff, planners, consultants and
non-profit groups in reviewing, auditing and
developing codes and ordinances that work
for their communities is a critical part of the
audit process.
Understanding how green infrastructure
fits within a municipality’s context is also a
key ingredient in overcoming code barriers.
What are the important local issues — the
regional culture, the pattern of develop-
ment and specific challenges regarding
water quality or quantity — and how might
greater use of green infrastructure help with
those issues?
Finally, communication and teamwork
are key. Kate Morgan, former water policy
director of 1000 Friends of Wisconsin,
noted, “With this project, we were building,
in many cases, new relationships with
municipalities and municipal staff. We
wanted to do it right, taking the time to
build a strong foundation and trust. We saw
this not as a one-off-and-done project but
rather an opportunity to set the stage for
future partnerships and projects to improve
water quality in the region.”
The health of rivers and streams
and, by extension, the health of
our communities, is bound to
how we live on and use the land.
TACKLING BARRIERS TO GREEN INFRASTRUCTURE 7
Green Infrastructure
Green infrastructure protects water quality
and reduces the quantity of stormwater
runoff by slowing it down, providing storage
and infiltration, and allowing evaporation
where it falls. These practices can be used
at the site or building scale, neighborhood
and public space scale or expanded to a
community-wide scale.
Examples of green infrastructure include:
■■Bioretention areas, such as plantings in
parking lot islands
■■Green roofs
■■Downspout disconnections into rain
barrels, planter boxes and permeable
areas
■■Rain gardens
■■Streets and alleys with permeable
surfacing
■■Bioswales
■■Native plantings
■■Wetland and floodplain preservation and
restoration
■■Conservation and protection of open
lands, natural areas and green spaces
■■Permeable and porous pavements and
paved surfaces
■■Urban tree canopy protection and
restoration, tree planter boxes and tree
trenches
City of Port Washington Wastewater
Treatment Plant green roof
8 TACKLING BARRIERS TO GREEN INFRASTRUCTURE
INTRODUCTION
The health of rivers and streams and, by
extension, the health of our communities,
is bound to how we live on and use the
land. With development and the associated
increase in impervious surfaces has come
a parallel rise in the negative impacts of
stormwater runoff on our natural resources
and communities.
As rainfall or snowmelt flows over developed
areas such as rooftops, roadways, parking
lots, construction sites and lawns, it picks up
and concentrates pollutants that end up in
storm drains that eventually discharge into
local rivers and streams. Stormwater runoff
can include automotive fluids, heavy metals,
sediment, nutrients, deicing salts, pesticides,
fertilizers and bacteria from human and
animal waste. Stormwater runoff is a leading
source of the pollution entering United
States waterways.
Impervious surfaces and waterways altered
through straightening and channel lining
increase the quantity and velocity of storm-
water runoff that can lead to flooding,
stream bank erosion, damage to property and
degradation of aquatic habitat. In addition,
increasing frequency and intensity of storm
events that deliver high rainfalls in short
periods of time are taxing traditional gray
infrastructure systems that were designed for
pre-21st-century precipitation rates.
Communities are looking increasingly to
green infrastructure to help mitigate the
impacts of stormwater runoff by managing it
where it falls. Mimicking natural hydrologic
processes and systems, green infrastruc-
ture practices are site-specific stormwater
management practices that spread out,
store and allow evaporation or infiltration
of rain and snowmelt. Distributed strategi-
cally across a drainage area, these practices
can significantly reduce stormwater flow
volumes, velocities and pollution loads.
Although green infrastructure is a proven,
effective means to mitigate stormwater
runoff, critical barriers remain to its imple-
mentation. Outdated, unclear or prohibitive
local regulations are a major barrier and one
that is readily addressed through a commu-
nity audit process.
If the code language is not
clear that green infrastructure
is an acceptable or preferred
approach to managing storm-
water, green infrastructure
will not likely be considered in
development proposals, design
plans or capital projects.
Green Infrastructure and
Local Regulations
Local codes and ordinances govern many
aspects of community life, including setting
standards for roads and sidewalks, land use
and development, maintenance of public
and private property, as well as others that
address public health and safety. Codes also
set forth the structure, process and proce-
dures for governance in a community.
Many codes and ordinances were written
before the effects of land use and develop-
ment on stormwater runoff were well under-
stood. Outdated local regulations can have
a broad impact on implementation of green
infrastructure — and often will directly or
indirectly discourage or prohibit its use.
Even the absence of language referring
to green infrastructure is a barrier. Where
codes are ambiguous or silent, code interpre-
tation by local staff and administrators may
affect whether the community, builders or
developers are willing or able to use green
infrastructure practices.
Zoning regulations, in particular, have an
outsized impact on the potential for imple-
mentation of green infrastructure. Standards
and requirements for applications for
development projects, site plans, stormwater
management plans, landscaping standards,
and parking and roadway requirements
are particularly important for encour-
aging or even requiring the use of green
infrastructure.
TACKLING BARRIERS TO GREEN INFRASTRUCTURE 9
Codes and ordinances that encourage or
require the use of green infrastructure can
help a community improve the health of
local waterways, promote public health,
protect private and public properties from
flooding and become, overall, more resilient
to a changing climate.
This workbook will provide a starting point
for tackling barriers in local regulations. It
has been developed to help communities
review and revise their codes and ordinances
with the goal of improving stormwater
runoff mitigation by enabling, encouraging
and promoting green infrastructure.
In this workbook we describe a community-
oriented approach to identify the needs
of the municipality or county, provide a
detailed audit tool, highlight common key
challenges and recommend next steps.
Who Should Use This Workbook?
This workbook is intended to help commu-
nities identify and revise local codes and
ordinances to allow for and support the
implementation of green infrastructure. It
may be useful if your community:
■■has policies that support green and
sustainable outcomes, or would like to
move towards these goals
■■must meet stormwater regulatory
obligations (e.g., municipal separate
storm sewer system (MS4) stormwater
permits, total maximum daily load
(TMDL) allocations)
■■participates in FEMA hazard miti-
gation planning, the Community
Rating System or other resilience
planning programs
■■experiences nuisance flooding and/or
stream bank erosion
■■is undertaking or planning an update of
the comprehensive/master plan
■■has natural water resources that are
recognized by the community as
important, or integral, to its identity
This workbook was written for use by county
and municipal staff, particularly those with
roles in zoning, land use, urban forestry,
stormwater and engineering. Secondary
audiences include planning and zoning
commissioners and board members; local
elected officials; and consulting civil engi-
neers, landscape architects and planners
who prepare development, landscape and
engineering plans. Organizations, nonprofits,
university extension and government
agencies whose mission is to protect water
resources or promote community resiliency
might also be interested in using this tool to
advance green infrastructure.
If you need assistance with this workbook or
have questions and comments, please contact
Julia Noordyk, water quality and coastal
communities outreach specialist, University
of Wisconsin Sea Grant Institute at
jnoordyk@aqua.wisc.edu or (920) 465-2795.
Original §CODE.code.1234 Amended §CODE.code.1234
A landscaping plan shall show the dimensions of
planted areas and proposed species.
The landscaping plan shall incorporate the storm-
water management approach and grading plan for
the site and shall indicate clearly the location and size
of all landscaped and vegetated areas, green roofs,
rainwater storage systems and areas of permeable
surfacing that are intended to provide stormwater
treatment or control functions.
Incorporating green infrastructure into site plan reviews. If the code language does not clearly state that green
infrastructure is an acceptable or preferred approach to managing stormwater, green infrastructure will not
likely be considered in development proposals, design plans or capital projects.
10 TACKLING BARRIERS TO GREEN INFRASTRUCTURE
Maryland Avenue Montessori School rain garden, Milwaukee
TACKLING BARRIERS TO GREEN INFRASTRUCTURE 11
amount of impervious surface or limit it. The
use of grassy swales or ditches in appropriate
areas, if permitted, rather than curb and
gutter drainage, can also provide infiltra-
tion for stormwater runoff. Regulations can
also be amended to allow for curb cuts and
bump outs that channel stormwater into
bioswales or bioretention areas (which often
do double-duty as traffic-calming methods)
to provide stormwater infiltration.
Streetscapes
Using trees and structural soils can play a
large role in streetscape stormwater manage-
ment. Trees capture, store and release
stormwater through evapotranspiration and
diffuse rain falling through the tree canopy,
reducing erosion and slowing peak flows.
Intricate root structures create greater soil
porosity, enabling more stormwater to infil-
trate the soil. Green infrastructure-friendly
streetscape regulations can require or
encourage street trees and ensure there is
adequate space and soil volume to support
mature trees by providing for sufficient green
space, tree boxes or tree trenches. Technical
in more detail and also provides ideas for
amending codes to overcome these barriers.
Reduce Impervious Surfaces
and Disconnect Effective
Impervious Areas
Surface Parking and Driveways
Parking requirements can yield significant
opportunities to reduce impervious surfaces
and to “green” parking areas. Amendments
can both reduce the total surface area
required and reduce the impact of those
surfaces. Amendments can take the form of
reducing the size of parking spaces, updating
parking ratios of number of spaces required
per square foot of building area, providing
procedures and systems1 to enable off-site
and shared parking and allowing waivers if
a use does not need the number of spaces
required for the size of the building.
Expansive parking areas and wide drive-
ways for residential properties can also
result in the spread of impervious surfaces
and increases in effective impervious areas.
Reducing minimum required driveway
widths, setting maximum driveway widths
and reducing or eliminating limits on
parking on lawns can keep these in check.
Right-of-Ways and Street Widths
Regulations pertaining to streetscapes
— street widths, right-of-way areas and
setbacks — can either increase the overall
WHAT YOU NEED TO KNOW BEFORE THE AUDIT:
KEY STRATEGIES AND COMMON BARRIERS
The audit focuses on five key strategies to
overcome barriers in codes and ordinances to
enable green infrastructure, reduce imper-
vious surfaces and protect water quality.
Three of the strategies — reduction of
impervious surfaces, disconnection of
effective impervious areas and restoration of
natural functions — relate directly to green
infrastructure and other engineered practices
that mimic hydrological processes to manage
stormwater and snow melt. An effective
impervious area directly connects to surface
waters via impervious surfaces and storm
drains, without an intervening permeable
surface or treatment system.
The fourth strategy recommends additional
standards for specific land uses that can
generate stormwater pollution and need
special attention during development review.
The fifth strategy is encouraging the use
of green infrastructure in comprehen-
sive plans, grant applications and purpose
statements as the preferred approach to
stormwater management.
In the final section, the audit process, your
community team will examine codes and
ordinances to determine where these key
strategies could be implemented.
Often, there are common code barriers (see
Table 1) that communities encounter. The
following section describes the relation-
ship between the strategies and regulations
Encouraging the use of
permeable materials through
regulations can “green”
parking lots, driveways,
sidewalks, alleys, parking
lanes and median strips.
12 TACKLING BARRIERS TO GREEN INFRASTRUCTURE
Work with your fire department and city
engineer to discuss acceptable alternatives
that can meet the need for public safety and
also reduce imperviousness. For example,
permeable pavers can be used for part of the
fire protection access needed for a building.
Grass pavers have been used successfully
for this purpose. Some fire departments will
approve reduced impervious surface require-
ments if buildings are equipped with sprin-
kler systems.
widths, intersection dimensions, cul-de-sac
radii and pavement requirements around
buildings. Access requirements can lead
to the construction of substantial areas of
impervious surface on a site.
Allowing permeable surfacing to be used for
areas of a site that provide access for public
safety and firefighting equipment but other-
wise do not see regular use is an important
strategy in reducing stormwater pollution
loads and runoff volumes.
standards for tree pits and tree boxes that
incorporate stormwater management can
also be referenced in the code.
Surfacing Materials
Permeable and porous surfacing materials
percolate, filter and slow down drainage
of stormwater and snowmelt which can
mitigate runoff volumes and pollution.
Encouraging or enabling the use of perme-
able materials through regulations can
“green” parking lots, driveways, sidewalks,
alleys, parking lanes and median strips.
Even the strategic, limited use of permeable
surfacing in an alley, parking lane or portion
of a parking lot can have substantial water-
quality benefits.
Using permeable materials successfully
requires help from contractors and engineers
with knowledge of where and how to design,
install and maintain these products. Since
permeable materials have specific mainte-
nance requirements that vary by brand and
type, adding reference in the code to stan-
dard specifications or performance standards
for permeable materials can give devel-
opers and contractors important guidance.2
Effective language in stormwater permits
and maintenance plans also ensures mainte-
nance information is passed to owners and
building and grounds managers.
Fire Protection Standards
In some communities, written or informal
standards related to firefighting equipment
building access translate to required road
Key Strategies to Mitigate Runoff
with Green Infrastructure
Common Code Barriers
Reduce impervious surfaces and maximize vege-
tated/landscaped areas that promote infiltration,
evaporation and evapotranspiration of rainwater
Dimensional standards: lot size, frontage, height,
coverage, yards, parking
Building codes and public works standards (drains,
roads, curb and gutter, sewers, ditches)
Disconnect effective impervious areas and diffuse
runoff to either vegetated areas or green infrastruc-
ture installations practices
Building codes, engineering and public works
standards (drains, roads, sewers, ditches)
Landscaping, buffers, trees and tree canopy
Restore and protect natural functions of soils and
vegetation
Landscaping, buffers, trees and tree canopy, open
space, erosion control requirements
Control pollution from specific sources, such as
animal-related uses, outdoor storage and trash
handling areas
Site plan review, special and conditional uses
Clarify the intent and purpose of codes to encourage
green infrastructure use
Comprehensive plan, purpose statements,
applications
Table 1: Key strategies for mitigating runoff with greater implementation of green infrastructure in local codes
and corresponding common barriers. Courtesy of Juli Beth Hinds, Orion Planning and Design.
TACKLING BARRIERS TO GREEN INFRASTRUCTURE 13
Residential Landscaping
Restrictions on residential landscaping
requiring turfgrass, a prescribed group of
plants to fit community aesthetics or limits
on plant heights all prohibit homeowners
from using native plantings or installing rain
gardens as methods to manage stormwater.
This barrier can be overcome by adding affir-
mative guidance or standards for these prac-
tices — for example, by requiring that native
lawns or plantings be managed or delineated
to keep an attractive appearance.
Shorelines, Riverbanks, Buffer Zones
While most local regulations will protect
shorelines and riverbanks with designated
buffer requirements, many communities
allow a mowed turfgrass area to serve as the
required buffer. As stated above, turfgrass
does not absorb and infiltrate stormwater
effectively in most cases, and the mainte-
nance of turf grass can contribute pollutants
that are detrimental to the waterways the
buffer was intended to protect.
Requiring the use of native or deep-rooted
vegetation, shrubs and/or trees rather than
turfgrass for the buffer strip will greatly
reduce runoff volumes into streams and
reduce or eliminate the need for fertilizers
and pesticides. Communities can also reduce
these pollutants by adopting policies explic-
itly stating fertilizer and herbicide appli-
cations should be minimized within buffer
areas.
can be integrated almost anywhere land-
scaping is required for screening and
aesthetic purposes. Codes that require a set
number of plants per area, as well as the type
of plantings required (e.g., dense evergreen
hedge) can be amended to be less prescrip-
tive and encourage the use of green infra-
structure for landscaping.
Turfgrass
Turfgrass, as commonly installed, does
not allow substantial infiltration due to its
root structure and soil substrate. Turfgrass
maintenance typically requires the use
of herbicides, pesticides and fertilizers
that contribute to stormwater pollution.
Landscape codes that require turfgrass for
landscaping can be amended to allow the use
of native plants and even require soil amend-
ments, which increase infiltration rates and
reduce the amount of runoff entering local
waterways.
In addition, avoid access problems by adding
stipulations that 1) these areas will be snow-
plowed or otherwise kept accessible during
the winter and 2) site plans require desig-
nated snow storage areas that do not impede
access — an important site plan standard for
any community to consider. Enforcement
is always crucial in ensuring that site plan
conditions are followed.
Restore and Protect Natural
Landscape Functions
Most green infrastructure practices use
the natural processes of plants to mitigate
stormwater runoff. Incorporating storm-
water control measures into regulations
related to landscaping, native plantings
and lawn requirements is a logical place to
either encourage or require the use of green
infrastructure in every new development or
redevelopment project.
Parking Lot Landscaping
and Screening
Parking lot landscape requirements are
often prohibitive to green infrastructure.
These regulations are rife with directives for
bermed screening and conventional curbing
for landscaped islands and edges of parking
lots. Amendments to these codes open the
way for bioswales and bioretention areas at
the lot edges and green practices in land-
scaped islands.
If standards are adjusted to ensure that visual
screening occurs through a combination of
fencing and plantings, green infrastructure
If standards are adjusted to
ensure that visual screening
occurs through a combination
of fencing and plantings, green
infrastructure can be integrated
almost anywhere landscaping
is required for screening
and aesthetic purposes.
14 TACKLING BARRIERS TO GREEN INFRASTRUCTURE
graded so runoff drains away from storm
sewers and surface waters; and receptacles
not permitted to be sited in a stream or
wetland buffer.
Ensuring that potentially dangerous mate-
rials are not stored in an open outdoor
area and that drainage from other outdoor
storage is buffered through a vegetated area
rather than being directed to storm drains or
surface waters will also curb runoff pollution
from these uses.
Vehicle Storage and Maintenance
Similarly, uses that include storage, mainte-
nance and cleaning of vehicles can require
siting in such a way that all discharge or
runoff be directed away from storm drains,
gutters, wetlands and waterways. If water is
used for cleaning shop floors and adjacent
outdoor areas, the wash water should be
contained and disposed of appropriately in
the sanitary sewer (with review and concur-
rence from the sanitary sewer provider) or
at an offsite disposal facility. Activities and
materials that occur outside and could come
in contact with rain and snow should be
covered to prevent runoff contamination.
An additional standard can require the
submission of a detailed plan for the collec-
tion, treatment and discharge of wash water
and runoff. The inclusion of maintenance
areas can be required information for review
of the site plan.
dog run or storage area to a grass or vege-
tated area and away from surface waters or
storm drains.
For other activities, consider requiring more
specific standards for collection, treatment
and disposal of the discharge to the sanitary
sewer. Providing for supplemental review of
these uses by engineering staff during the
development approval process often prevents
situations from becoming water quality
problems in the first place.
Outdoor Storage and Waste Handling
Dumpsters and trash storage areas are a
chronic issue for watershed health. Poorly
managed trash areas can allow animals to get
into the trash or drainage from food waste
to reach storm drains or surface waters,
which can produce significant discharges
of bacteria to streams and lakes. Ensuring
that trash areas are secure and reviewed
for drainage impacts is essential. Outdoor
storage and waste handling requirements
should include provisions that waste and
trash receptacles be fully enclosed; surface
areas for the receptacles be curbed and
Protection of Existing
Vegetation and Trees
Existing vegetation can be given additional
protection during construction projects with
the inclusion of specific, detailed require-
ments to mark disturbance areas, protecting
areas within the “drip line” of mature trees
and existing vegetation at construction sites.
Verification of these boundaries — which
can simply be ribboned or fenced off — can
be added to regular construction-phase
inspections. These additional measures,
which do not add to project costs, can be
extremely valuable in preserving natural
areas, soil functions and trees.
Pollution Source Reduction
From Conditional/Special Uses
Conditional or “special” uses permitted
in zoning districts such as animal-related
facilities (e.g., doggie day care, veterinary
hospitals, kennels, etc.), restaurants and
supermarkets, contractor yards, landscaping
and garden centers, and vehicle repair and
fueling stations, can be direct sources of
stormwater pollution. Pollutants from these
uses include pathogens, sediment, nutrients,
pesticides and herbicides, heavy metals and
toxic fluids from vehicles.
To address pollution stemming from these
uses, many common-sense standards can be
developed and adopted that direct discharge
or runoff away from storm drains, gutters,
wetlands and waterways. For example,
runoff can be redirected from an outdoor
Bradford Beach rain garden, Milwaukee
TACKLING BARRIERS TO GREEN INFRASTRUCTURE 15
Development applications and plan reviews,
planned unit development agreements and
tax increment finance (TIF) applications
are opportunities to require that a review
for green infrastructure and stormwater
management is brought into the early stage
of a project or planned development. This
signals to a developer alternative solutions
for stormwater management are desired. A
TIF policy can incentivize green infrastruc-
ture through the TIF’s finance structure.
Some communities have department staff
or elected officials who are advocates for
sustainable water resource protection and
who understand the importance of green
infrastructure. This leadership is often seen
in innovative programs and projects within
the community. If, however, those priorities
are not clearly codified in plans or purpose
statements, they can evaporate with a change
of leadership. Detailing goals for resource
protection and establishing the importance
of green infrastructure in purpose statements
and comprehensive plans can translate lead-
ership into legacy.
Clarify the Intent and Purpose
of Regulations and Standards
A community’s comprehensive plan offers
an opportunity to explicitly state that the
protection of water resources and use of
green infrastructure practices to protect
those resources are part of the community
vision. When these are incorporated, the
comprehensive plan can integrate water
quality and watershed health with its plans
for growth and development. It communi-
cates a clear intent to promote or require the
use of green infrastructure through regula-
tion, permits and plan review.
Purpose statements in zoning districts also
can be used to set forth goals to incorporate
stormwater management with landscape
requirements and to reduce impervious
surfaces. In some cases, zoning ordinances
can also be amended to include on-site
stormwater management as an allowable
use, especially retrofits that add bioretention
areas or restoration areas.
Snow Storage
Snow storage is an often-overlooked but
important component of site plan review.
Snow storage typically occurs in or near
parking areas, and snow piles can, in some
cases, take up required parking or impede
use of pedestrian access areas. Snow melt is
a source of a variety of pollutants, including
sediment, nutrients and heavy metals, as
well as chlorides and other deicing chem-
icals. When properly sited, designed and
maintained, snow storage areas can signifi-
cantly reduce the discharge of poor quality
meltwater to receiving waters and other
sensitive areas.
Identifying snow storage areas on site plans
and taking into account snowmelt runoff
impacts can be incorporated into application
checklists and site plan review standards.
Vegetated or grassy swales3 can be used for
snow storage and may be helpful in reducing
snow melt peak flows through infiltration
and in treating most pollutants associated
with snow. When storing snow in land-
scaped areas, plant species should be selected
based on their tolerance for snow storage.
Plants should be salt-tolerant perennials
that die back annually and shrubs or trees
that can bend with weight without breaking.
Spring maintenance might also be necessary
for areas that accumulate a buildup of sand.
Maryland Avenue Montessori School rain garden,
Milwaukee
16 TACKLING BARRIERS TO GREEN INFRASTRUCTURE
Rain garden or trash collector?
A community installs a rain garden with hopes of
reducing stormwater pollution and beautifying its
downtown. As it’s the first time the city engineers
have designed an urban rain garden feature,
pretreatment and energy dissipation features are
not included, and maintenance is not as frequent
as required. Within a year, the rain garden has
filled with sediment and trash, which causes it to
overflow, ironically, into the river it was intended
to protect. Now faced with the very public and
visible failure of its pilot project, the community’s
leaders are hard-pressed to support new green
infrastructure projects.
How can we change this story line? While we
know that perceptions and experiences can be
major barriers for a community to overcome,
there are things citizens, boards and committees
can do. First, this is an opportunity to enhance
dialogue between departments and staff,
particularly bridging planning and engineering.
In addition, operation and maintenance respon-
sibilities, frequencies and roles must be assigned
and carried out. The people charged with these
tasks must have proper technical support from
Bradford Beach rain garden, Milwaukee
others, such as local university extension staff
or engineering firms, to ensure these tasks are
done correctly. Long-standing neighborhood
associations, downtown business associations
or business improvement districts can make
great allies for green infrastructure maintenance
through cooperative agreements because they
develop a sense of ownership of projects located
“in their backyard.”
Perhaps even more important is the commu-
nity’s role in the upkeep of rain gardens and
other bioretention systems. Residents and
community groups who become caretakers
can greatly increase the chance for success
and improve public perception. They can often
contribute to day-to-day aesthetic maintenance
more often than staff. In addition to some initial
outreach and education with residents, the
key to developing this sense of ownership is
to give the project a healthy start with proper
design, construction and frequent maintenance
(watering) until the “bio” in the bioretention has
become established. Then, it can be a source of
pride for the residents who care for it.
TACKLING BARRIERS TO GREEN INFRASTRUCTURE 17
Community Scoping: Get to Know Your Community
Understanding green infrastructure in the context of your community and its culture is
central to making successful changes to your local regulations that will enable and promote
the use of green infrastructure.
The effects of local regulations are partly a result of what is written in the code — the
language itself — but also partly a function of how the community’s elected and appointed
officials, staff and developers interpret the code during the review process. Perceptions about
and experiences with green infrastructure from any sector of your community can aid or
thwart efforts to adopt code and ordinance amendments.
The background information you collect in this step is likely to indicate where you may
encounter pushback and help you develop a strategy to counter it. This information will
also help you identify natural allies — individuals, groups or businesses — who might
be supportive in moving your community toward greater green infrastructure acceptance
and implementation.
In addition, knowing your community’s identity is critical to ensure that changes to local
regulations will incorporate and build upon the preferences and priorities of the community.
Green infrastructure can then be framed as a strategy to help the community achieve many
broader goals.
The questions on the following worksheet will provide valuable background information
about your community in the context of green infrastructure implementation. This worksheet
will help identify obstacles, opportunities for troubleshooting and the most logical codes to
prioritize for revisions.
HOW TO AUDIT LOCAL CODES AND ORDINANCES
There are three main steps in the local codes
and ordinances audit:
1. Community scoping In this step, get to
know how your community’s experiences,
attitudes and preferences can affect efforts
to implement green infrastructure. You
will explore your community’s identity
as related to aesthetics and culture and
look for opportunities to build green
infrastructure support as the results of the
audit emerge.
2. Audit your community’s codes and
ordinances Using the audit section, assess
whether specific regulations are supportive
(a practice is encouraged or required),
prohibitive (a practice is not allowed),
ambiguous (confusing) or absent (nothing
is stated, for or against) regarding the use
of green infrastructure. The questions are
organized by code, policy and operational
topics where barriers to green infra-
structure practices are commonly found.
The grading system will help identify
which codes and ordinances pose the
biggest barriers.
3. Prioritize recommendations and
develop a strategy for adoption Use the
scoping information from step 1 along
with the results of the audit to guide
prioritization of recommended code
revisions and amendments. This will help
you develop a strategy that best fits the
needs of your community and is met with
greater acceptance.
18 TACKLING BARRIERS TO GREEN INFRASTRUCTURE
City of Port Washington Wastewater Treatment Plant green roof
COMMUNITY SCOPING WORKSHEET TACKLING BARRIERS TO GREEN INFRASTRUCTURE 19
COMMUNITY SCOPING WORKSHEET
3.Does the community’s hazard mitigation plan identify green
infrastructure as a mitigation activity?
■ Yes ■ No
Natural Assets
1.What are the natural resources of your community?
■ Rivers
■ Streams
■ Lakes
■ Public or private property with water frontage
■ Other important natural areas
2.Are those natural resources incorporated into the
community’s culture, such as for events?
■ Yes ■ No
If yes, how? _______________________________________________
__________________________________________________________
__________________________________________________________
__________________________________________________________
Investigating concerns about or objections to green infrastructure can help you understand why a community may be
hesitant to implement green infrastructure. A dialogue about these issues can give you critical information regarding the
community’s experience with green infrastructure.
Community Planning
1.Has a comprehensive plan been adopted for the community?
■ Yes ■ No
If yes, how are the community’s natural resources addressed in
the comprehensive plan? __________________________________
__________________________________________________________
__________________________________________________________
__________________________________________________________
If yes, is there specific attention to the community’s water
resources in the comprehensive plan?
■ Yes ■ No
If yes, is green infrastructure implementation listed as a key
element for implementation?
■ Yes ■ No
2.Has your community taken part in the development of a
watershed restoration or other similar plan?
■ Yes ■ No
20 TACKLING BARRIERS TO GREEN INFRASTRUCTURE COMMUNITY SCOPING WORKSHEET
3. Are there impaired resources, vacant lots or sites (e.g.,
degraded wetlands/shorelines, contaminated sites, flood-
prone areas) that would be good targets for remediation or
restoration?
■ Yes ■ No
__________________________________________________________
__________________________________________________________
__________________________________________________________
If yes, would green infrastructure be suitable for these sites
(e.g., stormwater infiltration may NOT be feasible on a
brownfield redevelopment)?
■ Yes ■ No
If yes, these can often be good sites to demonstrate new
ideas and practices.
4. Is there public access to local rivers, lakes and natural areas?
■ Yes ■ No
If yes, where and what type? _______________________________
__________________________________________________________
__________________________________________________________
__________________________________________________________
Hazards
1. Is your community challenged with any of the following
flooding issues?
■ Basement backups
■ Wet basements
■■■Street flooding
■■■Stream or river overflow
■■■Ponding in yards and green spaces
■■■Other__________________
2. Have stormwater outfalls, culverts and bridges been
surveyed for potential pollution issues?
■ Yes ■ No
3. Does your community experience beach or swimming area
closures after storms due to high bacteria levels?
■ Yes ■ No
If yes, are the sources (or potential sources) of bacteria
documented or understood?
■ Yes ■ No
4. If streams or rivers are within your community’s boundaries,
are they on the state’s 303(d) list of impaired and threatened
waters7?
■ Yes ■ No
5. Does your community have issues with bluff or ravine
erosion?
■ Yes ■ No
COMMUNITY SCOPING WORKSHEET TACKLING BARRIERS TO GREEN INFRASTRUCTURE 21
Community Identity and Character
1. Is being “green” attractive to new people moving into
your community?
■ Yes ■ No
2. Does your community have any environmental,
sustainability or nature-based designations?
■ Yes ■ No
__________________________________________________________
__________________________________________________________
__________________________________________________________
3. Is your community a sister city to a city with water issues?
■ Yes ■ No
If yes, name of the city and list its water issues: ______________
__________________________________________________________
__________________________________________________________
__________________________________________________________
4. Have other environmental initiatives been started in your
community?
■ Yes ■ No
If yes, what is their focus? __________________________________
__________________________________________________________
__________________________________________________________
__________________________________________________________
5. Do residents of your community like a homogeneous
appearance to their neighborhoods or are individual
residents’ preferences tolerated or even celebrated?
__________________________________________________________
__________________________________________________________
6. Is turf grass the favored lawn cover or is there a more
diverse approach to residential landscaping that can include
native plantings, prairies and rain gardens?
__________________________________________________________
__________________________________________________________
22 TACKLING BARRIERS TO GREEN INFRASTRUCTURE COMMUNITY SCOPING WORKSHEET
Is green infrastructure encouraged in the review process?
■ Yes ■ No
5. Is your municipality required to have coverage under a
municipal separate storm sewer system (MS4) permit?
■ Yes ■ No
6. Does your community have total maximum daily load
(TMDL) allocation requirements that it must meet?
■ Yes ■ No
Current Green Infrastructure Usage
1. Have residents installed rain gardens or rain barrels?
■ Yes ■ No
2. Have any neighborhood associations or other organizations
initiated green infrastructure projects such as rain gardens or
stormwater tree programs?
■ Yes ■ No
If yes, please describe ______________________________________
__________________________________________________________
__________________________________________________________
__________________________________________________________
Stormwater Regulations
1. Does the community have a stormwater utility?
■ Yes ■ No
If yes, are the rates dependent on equivalent residential
units (ERUs)?
■ Yes ■ No
If yes, does the stormwater utility incentivize green
infrastructure through the reduction of ERUs and the
corresponding tax rate?
■ Yes ■ No
2. Is the stormwater ordinance up-to-date in accordance with
state law?
■ Yes ■ No
3. Does the stormwater ordinance include green infrastructure
practices as approved methods to address stormwater runoff
in new development and redevelopment projects?
■ Yes ■ No
4. What amount of development (e.g., half an acre of new or
redeveloped impervious surface, any site plan, an acre or
more of new development) triggers the requirement for a
developer to submit a stormwater management plan?
__________________________________________________________
When a stormwater development plan is required, are
reviewers knowledgeable about green infrastructure?
■ Yes ■ No
COMMUNITY SCOPING WORKSHEET TACKLING BARRIERS TO GREEN INFRASTRUCTURE 23
3. Are there community gardens?
■ Yes ■ No
If yes, what’s the water supply for irrigation?
__________________________________________________________
4. Are there formal or informal efforts to ensure maintenance
of subdivision ponds or other private green infrastructure
features?
■ Yes ■ No
5. Has your community implemented a downspout or
foundation drain disconnection program?
■ Yes ■ No
If yes, is this encouraged by the local government, or simply
allowed?
__________________________________________________________
If yes, who would respond to questions or provide technical
information on drain disconnection?
__________________________________________________________
6. Does your community have an issue with inflow and
infiltration?
■ Yes ■ No
Understanding Your Community
Learning about concerns or objections to green infrastructure
can help you understand why a community may be hesitant to risk
failure or not be in favor of codes that promote green infrastruc-
ture. A dialogue about these issues can provide valuable insight
into the cause of the failure and give you critical information
regarding the community’s experience with green infrastructure.
Menomonee Valley Redevelopment and Community Park,
native plantings, Milwaukee
24 TACKLING BARRIERS TO GREEN INFRASTRUCTURE COMMUNITY SCOPING WORKSHEET
11. Do you have subdivisions/neighborhoods that incorporate
conservation, low-impact development, sustainability
features or green infrastructure practices?
■ Yes ■ No
If yes, please explain: ______________________________________
__________________________________________________________
__________________________________________________________
12. Which of the following green infrastructure practices have
been implemented in your community?
■ Bioretention areas, such as plantings in parking lot islands
■ Green roofs
■ Downspout disconnections into rain barrels, planter boxes
and permeable areas
■ Rain gardens
■ Streets and alleys with permeable surfacing
■ Bioswales
■ Native plantings
■ Wetland and floodplain preservation and restoration
■ Conservation and protection of open lands, natural areas
and green spaces
■ Permeable and porous pavements and paved surfaces
■ Urban tree canopy protection and restoration
Which installations have been described as successful?
__________________________________________________________
__________________________________________________________
__________________________________________________________
7. Are there restrictions on the application and use of lawn
fertilizers and/or pesticides?
■ Yes ■ No
8. Are streams and rivers protected by regulated buffers?
■ Yes ■ No
If yes, how large a setback is required?
__________________________________________________________
If yes, what type of vegetation is required/allowed?
__________________________________________________________
__________________________________________________________
9. Is there awareness of coal tar sealant pollution?
■ Yes ■ No
10. Have any developers who have worked in your community
used green infrastructure?
■ Yes ■ No
If yes, with what success?
__________________________________________________________
__________________________________________________________
__________________________________________________________
COMMUNITY SCOPING WORKSHEET TACKLING BARRIERS TO GREEN INFRASTRUCTURE 25
14. Is there a government entity spearheading the acceptance
and/or adoption of green infrastructure (e.g., a sewerage
district, mayor’s office, etc.)?
■ Yes ■ No
__________________________________________________________
__________________________________________________________
_________________________________________________________
Community Acceptance
1. What community groups or associations would be natural
allies for green infrastructure?
These could include a park friends group, a garden club,
a Wild Ones chapter, a conservation committee, a school
that has the environment or sustainability as an organizing
theme, river or bay keepers, a Rotary Club, bicycling
advocacy group or village beautification committee.
__________________________________________________________
__________________________________________________________
__________________________________________________________
Which have been described as failed? _______________________
__________________________________________________________
__________________________________________________________
________________________________________________________
Was there community support for the projects?
■ Yes ■ No
If yes, was significant outreach needed to secure community
buy-in for any of the projects?
■ Yes ■ No
Was the community opposed to the project at the beginning or
at any points in the process?
■ Yes ■ No
If yes, how was the opposition addressed? __________________
__________________________________________________________
__________________________________________________________
13. Is there a green infrastructure initiative or project that the
community incorporated into its identity?
■ Yes ■ No
__________________________________________________________
__________________________________________________________
__________________________________________________________
Knowing your community’s identity is critical
to ensure that changes to local regulations
will incorporate and build upon the
preferences and priorities of the community.
26 TACKLING BARRIERS TO GREEN INFRASTRUCTURE COMMUNITY SCOPING WORKSHEET
2. Are there neighborhood associations with a strong
environmental ethic and commitment to sustainability?
■ Yes ■ No
__________________________________________________________
3. Which companies or businesses (e.g., garden centers
or landscaping contractors) within your community
have a strong environmental ethic and commitment to
sustainability?
__________________________________________________________
__________________________________________________________
__________________________________________________________
4. Are there individuals who are advocates for green
infrastructure and green practices in your community?
■ Yes ■ No
List individuals and what types of practices they support: _____
__________________________________________________________
__________________________________________________________
__________________________________________________________
5. Are there individuals who are opposed to green
infrastructure and other environmental initiatives?
■ Yes ■ No
If yes, what is the basis of their concern or objection?
__________________________________________________________
__________________________________________________________
__________________________________________________________
6. Do you have code and ordinance changes reviewed by
an attorney?
■ Yes, always
■ Sometimes
■ Rarely
■ Never
If yes, is this an impediment to making change?
■ Yes ■ No
7. What is your community’s attitude or approach towards
changing regulations?
■■Positive, willing/able to take on
■■Neutral, not proactive, but few objections when routine
change is made
■■Challenging, changes likely to receive intense scrutiny or
to lead to objections.
__________________________________________________________
__________________________________________________________
__________________________________________________________
TACKLING BARRIERS TO GREEN INFRASTRUCTURE 27
Audit Your Community’s Codes and Ordinances
Using the audit section of this workbook (see the tabbed section), thoroughly review the
codes and ordinances to identify barriers to the use of green infrastructure for stormwater
treatment and control for private and public projects.
Prioritize Recommendations and Develop a Strategy for Adoption
Prioritizing Code Amendments
The report card at the end of the audit section will help your team identify areas where critical
barriers exist. The codes identified in the topic area with the most low scores are a logical
starting point. There are likely to be many codes and ordinances in several topic areas needing
revision. If this is the case, it may be helpful to use additional criteria or information to priori-
tize the next phase of work.
Knowing what development pressures your community is facing can help determine which
amendments to prioritize.
Is your community built out with most development occurring as redevelopment? If so,
this might lead to a prioritization of amendments that would enable shared or offsite parking
and permit permeable materials for parking lot surfacing, green roofs or planter boxes for
rainwater harvesting.
Does your community have large parcels available for new development? This might lead
to the prioritization of regulations pertaining to the size of individual parking spaces and
number required, or reducing the footprint of roads and culs-de-sac in subdivision standards.
Parking lot landscaping requirements could be amended so landscaping is allowed or required
to serve as stormwater management. If there is little development or redevelopment planned,
a focus on enabling green infrastructure practices on residential properties could take priority.
Are there regulations or requirements affecting your community? Your municipality
may have regulatory requirements in addition to a MS4 stormwater permit such as a total
maximum daily load (TMDL) that requires the reduction of pollutants identified in a TDML
implementation plan or combined sewer overflow problems. Removing barriers to green
infrastructure practices could help mitigate specific pollutants identified in a TMDL, which
would make codes relevant to that area a high priority for revision.
The scoping information will also help in developing an approach that best fits your commu-
nity and in assembling a team of local allies to encourage greater use of green infrastructure.
This, in turn, can inform any public outreach and education efforts that might be needed to
advance the adoption of the recommended changes.
The importance of a successful
green infrastructure project to
the goal of advancing green
infrastructure in your community
cannot be overstated. A failed
project can have a crippling
effect on subsequent green
infrastructure initiatives.
28 TACKLING BARRIERS TO GREEN INFRASTRUCTURE
Overcoming Other Hurdles
In addition to specific local regulations, perceptions about and experiences with green
infrastructure can be significant barriers to widespread implementation of these practices.
Concerns about failure, cost and maintenance will need to be addressed.
If a project has failed in the community or been poorly received, it is critical to determine
the root causes of that failure. This information can help in the development of a strategy to
advance recommended amendments through the approval process and address resistance to
proposed changes.
Before amendments are reviewed by the planning commission or other board, enlist the
support of allies identified in the community scoping activity. Outreach to these allies can
build support for green infrastructure and potentially identify early adopters for a particular
initiative. Community allies can be called on to speak in favor of green infrastructure and
associated ordinance changes in your local code adoption process whether that is at public
hearings, subcommittee meetings or board or commission meetings.
Residential green infrastructure practices can also present challenges. Concerns about
negative comments from neighbors can be a disincentive even if a practice is allowed in
the community. Some have found a simple permit that is easy to fill out and submit electron-
ically for residential practices such as rain gardens, cisterns and natural yards can help manage
neighbor relations proactively.
For instance, if a resident would like to install a rain garden but is concerned that neighbors
would complain, he or she can submit an application for a rain garden permit. This gives
residents added reassurance to move forward with rain garden plans and enables municipal
staff to communicate to concerned neighbors that rain gardens are an approved form of
landscaping. This simple step provides a straightforward response to a complaint call, “Yes, it
is allowable and your neighbor has a permit on file to use that practice.”
The cost of green infrastructure may be a concern among staff or elected officials. There are
many well-researched studies and reports on this topic that compare green infrastructure
practices to conventional gray infrastructure and stormwater management approaches. Links
to several of these reports are included in the resources section of this workbook.
Local staff may also cite maintenance of green infrastructure installations and concerns
about effectiveness. Case studies, strategies and maintenance manuals are available to help
counter these concerns. Some of these are included in the resources section.
Reed Street Yards, bioswale, Milwaukee
TACKLING BARRIERS TO GREEN INFRASTRUCTURE 29
Follow Through
The complete code audit — drafting revisions and adopting recommendations — sets the
stage for greater use of green infrastructure. With green infrastructure enabled, developers,
contractors and communities will consider green infrastructure as a potential component of
their projects. When projects incorporate green infrastructure as a result of a code amendment,
use the projects as opportunities to build greater acceptance for green infrastructure.
Track projects that are associated with the revised codes through the design, public input and
installation phases to ensure a successful project. Strategic outreach to inform residents about
new development, redevelopment or capital improvement projects that incorporate green
infrastructure is critical to their acceptance. Time invested in public outreach to educate resi-
dents about green infrastructure and its benefits can help foster greater buy-in for the project.
The importance of a successful green infrastructure project to the goal of advancing green
infrastructure in your community cannot be overstated. A failed project can have a crippling
effect on subsequent green infrastructure initiatives.
Amending codes and ordinances to enable green infrastructure is only the start of your work.
Long-term community acceptance and support for green infrastructure is built on outreach
and education to officials and residents and the successful implementation of projects.
Outreach to allies builds
understanding about the
importance of the desired
green infrastructure
practice and potentially
identifies early adopters
for a particular initiative.
Menomonee Valley Redevelopment and Community Park, stormwater wetlands, Milwaukee Reed Street Yards bioswale, Milwaukee
30 WHAT’S THE IMPACT TACKLING BARRIERS TO GREEN INFRASTRUCTURE
WHAT’S THE IMPACT?
The effects of local regulations on stormwater runoff management and green infrastructure
implementation can be abstract and difficult to understand. Geographic information system
(GIS)-based stormwater models offer an effective tool for demonstrating and communicating
the impacts of green infrastructure-friendly codes and ordinances in your community.
The following examples highlight particular code revisions and amendments that would
enable green infrastructure practices and reduced impervious surface at different sites in the
greater Milwaukee area. The sites illustrate the potential benefits of:
■■ Incorporating bioretention in general landscaping requirements.
■■ Using native or deep-rooted plants with ample soils in place of turfgrass.
■■ Reducing the total impervious area associated with parking requirements.
■■ Allowing the use of permeable surfacing in parking lots, driveways, fire protection areas
and alleys.
■■ Incorporating tree planting, native plants and soil amendments (use of aeration and
top dressing with organic fertilizer to foster root development and increase infiltration
in turfgrass).
For each parcel, the following question was asked: If development or redevelopment of this
site occurred after the recommended code change was made, incorporating green infrastruc-
ture practices, what would be the impact on water quality and the quantity of runoff?
Modeling Methodology
For each site, a hypothetical redevelopment project was modeled to determine the associated
stormwater runoff volume and pollution load reductions from existing conditions. The team
used WinSLAMM version 10.2.0, the source loading and management model developed by
PV & Associates llc, to model the existing development conditions and a post-code revision
redevelopment scenario with green infrastructure installations in place. ESRI ArcMap soft-
ware was used to measure parcel attributes, including roofs, parking lots and turfgrass areas.
Design assumptions for installed practices were based on engineering standards, constraints
of the site, type of best management practice (BMP) and goal of BMP (water quality, water
quantity, reduced peak flow rate, etc.).
Mequon Nature Preserve, native plantings
TACKLING BARRIERS TO GREEN INFRASTRUCTURE WHAT’S THE IMPACT 31
Infiltration rates were determined using soil types provided by municipal and federal GIS soil
layers. If the data were insufficient for the native soil type(s) on the parcel, a silty soil type was
assumed because it represents an average runoff condition as compared with sandy and clayey
soil options in the model and is commonly selected as the default soil type for modeling in
southeast Wisconsin.
Bioretention practices were modeled using the same geometry (height of practice, drain sizes,
etc.). Assumptions used in modeling bioretention practices included:
■■ Modeling software requirements of one 6-inch drain tile underdrain, vertical standpipe,
broad crested weir4
■■ 24 inches of engineered soil5 (75% sand/25% compost)
■■ 12 inches of rock fill under engineered media6
Permeable pavement practices were modeled using the same geometry (material specifica-
tions, depths and underdrain sizes). Assumptions used in modeling permeable pavement
included:
■■ Pavement thickness of 6 inches and porosity of 0.20
■■ Aggregate bedding thickness of 4 inches and porosity of 0.35
■■ Aggregate storage layer thickness of 12 inches and porosity of 0.35
■■ Initial infiltration rate of 100 inches/hour and surface clogging load of 0.06 pounds/
square foot
■■ Underdrain diameter of 4 inches and elevated 4 inches from bottom of storage layer
■■ Subgrade seepage rate of 0.3 inches/hour
■■ TSS reduction rate for flow through pavement of 55%
Conversion of turfgrass to native landscaping was modeled by changing the soil type from
silty to sandy soil type. This represents the increased infiltration capacity created through
establishment of deep-rooted native plantings and possible soil amendments.
The Brewery, infiltration trench, Milwaukee
Mequon Nature Preserve, native plantings
32 WHAT’S THE IMPACT TACKLING BARRIERS TO GREEN INFRASTRUCTURE
TACKLING BARRIERS TO GREEN INFRASTRUCTURE WHAT’S THE IMPACT 33
WHAT’S THE IMPACT: GREEN INFRASTRUCTURE STANDARDS FOR
PARKING LOT LANDSCAPING
Code Revision: Encouraging use of bioretention areas with curb cut inlets as
parking lot landscaping
24.12.020 Perimeter Vehicular Use Area Landscaping and
24.12.030 Interior Vehicular Use Area Landscaping
The integration of depressed bioretention areas used for landscaping and stormwater manage-
ment is are strongly encouraged. Where perimeter areas are designed specifically for storm-
water management, the planting and dimensional requirements of 24.12.020(B)(1) above may
be varied as necessary to ensure that the area functions effectively for stormwater treatment,
so long as in the judgment of the [plan commission, city engineer] an equivalent amount of
landscaping, planting or screening is provided.
Site: Parking lot redevelopment (total parking area 0.46 acre)
Addition of 2,310 square feet in bioretention
Runoff volume
reduction: 46%
Total suspended solids
reduction: 59%
34 WHAT’S THE IMPACT TACKLING BARRIERS TO GREEN INFRASTRUCTURE
TACKLING BARRIERS TO GREEN INFRASTRUCTURE WHAT’S THE IMPACT 35
WHAT’S THE IMPACT: SUBSTITUTING NATIVE VEGETATION FOR TURFGRASS
Code Revision: Encourage use of natives in lawn areas and limit total percent of
site in turfgrass
Chapter 122 – ZONING
Landscaping. A general description of landscaping standards, screening, and parking lot treat-
ments. Naturalized landscaping, the use of native vegetation, preservation of existing trees and
wooded area, and tree planting that will provide additional tree canopy on the site are encour-
aged. The use of turfgrass should be limited to those areas intended for outdoor recreation or
gathering areas.
Site: Non-residential development (lawn area 1.74 acres)
Substitution of native vegetation for entire lawn area7
Runoff volume
reduction: 74%
Total suspended solids
reduction: 64%
36 WHAT’S THE IMPACT TACKLING BARRIERS TO GREEN INFRASTRUCTURE
TACKLING BARRIERS TO GREEN INFRASTRUCTURE WHAT’S THE IMPACT 37
WHAT’S THE IMPACT: REDUCING TOTAL IMPERVIOUS AREA ASSOCIATED WITH PARKING
Code Revision: Reduce minimum parking ratio (spaces required per square foot of building
area) and set a maximum number of drive-through lanes. A retrofit of the site would require
the removal of two drive-through lanes to be in conformance with the ordinance.
Sec. 13-1-92 Parking Requirements.
(k) The Following Guide Specifies the Minimum Number of Parking Spaces Required.
(2) Retail Sales and Customer Service Uses; Places of Entertainment. Retail sales
and customer service uses, and places of entertainment, except as specifically set forth
below: one (1) space per two hundred (200) one hundred fifty (150) square feet of
gross floor area of customer sales and service, plus one (1) space per two hundred (200)
square feet of storage and/or office gross floor area, or if the use has at least eighty
thousand (80,000) square feet gross floor area, one (1) space per two hundred (200)
square feet of gross floor area.
a. Financial Institutions: One (1) per two hundred (200) one hundred fifty (150) square feet
of gross floor area of customer sales and service, plus one (1) space per employee for the work
shift with the largest number of employees. Financial institutions with drive-through service
facilities shall provide sufficient space for up to four (4) waiting vehicles at each drive-through
service lane.
Site: Commercial bank (total drainage area 33,000 square feet)
■•Remove two drive-through lanes
■•Park at 5.5 spaces/1,000 square feet = 44 spaces instead of 64 spaces
■•21% impervious cover reduction (convert impervious to turf grass8)
Runoff volume
reduction: 19%
Total suspended solids
reduction: 23%
38 WHAT’S THE IMPACT TACKLING BARRIERS TO GREEN INFRASTRUCTURE
TACKLING BARRIERS TO GREEN INFRASTRUCTURE WHAT’S THE IMPACT 39
WHAT’S THE IMPACT: ALLOWING AND INSTALLING PERMEABLE ALLEYS
Code Revision: Allow use of permeable surfacing in driveways and alleys
(3) Surfacing. All driveways shall be surfaced in accordance with village standards and
specifications so as to provide a durable and dust-free surface, and shall be so graded
and drained as to dispose of all surface water. Permeable surfacing may be used upon
review and approval by the village engineer.
Site: Residential alleyway (total drainage area 25,000 square feet)
Replace 5,600 square feet with permeable pavement
Runoff volume
reduction: 63%
Total suspended solids
reduction: 63%
40 WHAT’S THE IMPACT TACKLING BARRIERS TO GREEN INFRASTRUCTURE
TACKLING BARRIERS TO GREEN INFRASTRUCTURE WHAT’S THE IMPACT 41
WHAT’S THE IMPACT: LANDSCAPING WITH NATIVE GRASSES, TREE PLANTINGS
AND BIORETENTION
Code Revision: Encourage use of bioretention as landscaping and
landscape-based stormwater control
i. All yards sodded or seeded on at least 4 inches of topsoil. Rain
gardens defined in the Chapter may be incorporated into lawn
areas where planned and designed to receive drainage or runoff.
ii. Trees and shrubbery appropriate for the development, and
according to the plan approved under subsection (a) above.
The incorporation of amended soil areas, stormwater trees, and
other vegetative stormwater control measures into landscaping
plans is encouraged.
(c) Parking Lot Landscaping
1. Landscaping shall be provided on the perimeter and within
the interior of all parking areas to provide screening, canopy
cover, and stormwater treatment and control. The integration
of vegetated stormwater control measures with parking lot
landscaping is strongly encouraged. All landscaped areas shall
be mulched or seeded in keeping with the overall landscaping
plan. The Village may maintain a list of accepted species of tree
and landscaping materials, including plants and trees suitable
for use in vegetated stormwater control measures.
2. In parking lots, at least 5% of the interior parking area shall
be landscaped with planting, and one tree of a minimum
2-inch caliper, for each 10 spaces, all as shall be submitted
and approved as part of the plan provided for herein above.
Planting required within the parking lot shall be in addition
to, and not in lieu of, other planting requirements, such as for
street trees. The planting plan may be varied to accommodate
the design of vegetated stormwater control measures, so long
as the total number of required trees is met within the overall
parking area. The use of deciduous trees (which may function
as stormwater trees, as defined in the Chapter) is encouraged
to provide canopy shading within parking areas. Each interior
landscaped area shall be a minimum of 75 square feet in size.
Runoff volume
reduction: 56%
Total suspended solids
reduction: 64%
Site: Non-residential development (total area 4.12 acres)
■•All parking areas drain to bioretention treatment or tree
boxes (10,000 square feet)
■•Rooftop drains to rain gardens in landscaped areas
surrounding building
■•Access drive drains through native vegetation filter strip
■•All turfgrass replaced with native vegetation
42 TACKLING BARRIERS TO GREEN INFRASTRUCTURE
University of Wisconsin School of Freshwater Sciences permeable pavers, Milwaukee
TACKLING BARRIERS TO GREEN INFRASTRUCTURE 43
APPENDIX 1
Sample Zoning Definitions for Green Infrastructure Practices
The following are examples of definitions
of different green infrastructure practices.
Providing an umbrella definition of “green
infrastructure” or “vegetated stormwater
management measures” is one way to enable
green infrastructure in landscaped areas
without the need to differentiate among
such terms as “bioswale,” “bioretention
area,” “rain garden” or “vegetated swale.”
Note that these definitions should be
tailored to match the language structure of
your local ordinance and to reflect local or
state statutes, definitions and codes.
Green Infrastructure. Green infrastruc-
ture refers to those methods of stormwater
treatment and control that use the natural
capacities of soil and vegetation to prevent
or reduce stormwater runoff and associated
nonpoint source pollution. Green infra-
structure methods often are combined with
conventional or structural stormwater treat-
ment systems, such as separators, ponds or
underground systems, to create stormwater
“treatment trains” that enhance stormwater
treatment and water quality.
Amended soil areas. Amended soil areas
are landscaped portions of a site where
decomposed organic material has been
incorporated into the soil to improve its
performance for infiltration and growing
vegetation, enabling the area to function as
a vegetated control measure.9
Best management practice, or BMP. Best
management practice, or BMP, means
structural or nonstructural measures, prac-
tices, techniques or devices employed to
reduce peak flows and minimize sediment
or pollutants carried in runoff.
Bioswale. Bioswale means a vegetated,
mulched or xeriscaped channel that provides
treatment and retention as it moves storm-
water from one place to another.
Bioretention area or rain garden. A bioret-
ention area or rain garden is an excavated
area that is back-filled with a prepared or
amended soil mixture, covered with a mulch
layer and planted with a diversity of woody
or herbaceous vegetation to which storm-
water is directed to promote infiltration and
evapotranspiration.10
Cistern. A roof runoff collection system that
detains water in above-ground or under-
ground storage tanks with a capacity of at
least 100 gallons.11
Connected imperviousness. Connected
imperviousness means an impervious
surface that is directly connected to a sepa-
rate storm sewer or water of the state via an
impervious flow path.
Critical time. Critical time means the
period starting at the time of peak rainfall
intensity with a duration equal to the time
of concentration of the watershed.
Downspout disconnection. Downspout
disconnection means the rerouting of
rooftop drainage pipes that are connected
to storm sewers or that drain to impervious
areas in order to drain rainwater to rain
barrels, cisterns or permeable areas.
Green roof. An engineered roofing system
that includes vegetation planted in a
growing medium above an underlying
waterproof membrane material designed
to reduce the volume of stormwater runoff
from building roofs.12
Green wall. The use of a supporting
structure or wall panel that enables plants
to grow vertically along the façade of a
building or structure to provide air and
water quality functions as well as aesthetic
enhancement.
Impervious surface. Any pavement or
structural element that prevents rain, surface
water runoff or melting snow from infil-
trating into the ground, including, but not
limited to roofs and paved roads, driveways
and parking lots.13
Permeable surfacing. A material or mate-
rials and accompanying subsurface treat-
ments designed and installed specifically
to allow stormwater to penetrate into it,
reducing the volume of stormwater runoff
44 TACKLING BARRIERS TO GREEN INFRASTRUCTURE
from the surfaced area. Permeable surfacing
may include paver blocks, grassy pavers or
similar structural support materials and
permeable concrete or asphalt.
Planter box. Planter box means a structure
with vertical walls and an open or closed
bottom that may be attached to a building or
structure and is planted with a soil medium
and vegetation intended to collect, absorb
and treat runoff from impervious surfaces.
Pocket wetlands. Pocket wetlands are
small (typically under 1,000 square feet)
constructed wetlands designed to reduce
peak flows and runoff volumes, and remove
pollutants via settling and bio-uptake.14
Rain barrels. Rain barrels are structures
for the collection of roof runoff in
containers, typically ranging from 50 to
100 gallons, with subsequent release to
landscaped areas.15
Stormwater trees. Stormwater trees are
trees selected and installed (either with or
without an engineered box or structure)
as integral components of a stormwater
management plan, at points or sites where
the tree(s) will have the effect of increasing
the coverage of tree canopies to provide
stormwater interception and evapotrans-
piration, stormwater uptake and increased
infiltration.
Structural soil. A medium containing a
mixture of crushed stone, soils and other
materials that can be compacted sufficiently
to support the installation of pavement
or other surfacing, while permitting root
growth for trees or other vegetation.
Vegetated control measures. The term
“vegetated control measures” refers to
vegetated swales, bioretention areas, rain
gardens, amended soil landscape areas,
pocket wetlands, stormwater trees or similar
plantings that are designed and intended to
provide stormwater treatment and control,
and to promote evapotranspiration and infil-
tration of stormwater.
Vegetated swales. Vegetated swales are
stormwater conveyance systems routing
stormwater flows through vegetated areas
in a natural elongated depression or a
constructed channel. A vegetated infiltration
swale differs from a conventional drainage
channel or ditch because it is constructed
specifically to promote infiltration.
Maryland Avenue Montessori School rain garden, Milwaukee
TACKLING BARRIERS TO GREEN INFRASTRUCTURE 45
APPENDIX 2
Green Infrastructure Resources
Wisconsin Regulations
Wisconsin Department of Natural Resources Chapter NR 151 — Runoff Management
bit.ly/RunoffManagement
Wisconsin Department of Natural Resources Conservation Practice Standard 1008 — Permeable Pavement
bit.ly/PermeablePavement
Wisconsin Department of Natural Resources Conservation Practice Standard 1004 — Bioretention for Infiltration
bit.ly/Bioretention
Wisconsin Department of Natural Resources Conservation Practice Standard 1002 — Site Evaluation for Stormwater Infiltration
bit.ly/StormwaterInfiltration
Wisconsin Department of Natural Resources Non-Agricultural Revisions to Chapter NR 151, Runoff Management Rule
bit.ly/RunoffManagementRule
Valuing Green Infrastructure
Banking on Green: A Look at How Green Infrastructure Can Save Municipalities Money and Provide Economic Benefits Community-wide.
American Rivers, American Society of Landscape Architects, ECONorthwest and Water Environment Federation, 2012.
Explores economic impacts of stormwater and how green infrastructure can help offset these costs.
bit.ly/BankingGreen
Case Studies Analyzing the Economic Benefits of Low Impact Development and Green Infrastructure Programs. U.S. Environmental Protection
Agency, 2013.
Uses 13 case studies from across the United States using various economic methods to determine cost-benefit analysis of green infrastructure
and low-impact development projects.
bit.ly/EPAStudies
Green Infrastructure for Climate Resiliency. U.S. Environmental Protection Agency, 2014.
Identifies how green infrastructure can help communities build climate resiliency.
bit.ly/2ehcGQN
The Value of Green Infrastructure: Guide to Recognizing Its Economic, Environmental and Social Benefits. American Rivers and Center for
Neighborhood Technology, 2010.
Outlines the multiple economic, environmental and social benefits of green infrastructure and how to assess these diverse benefits to guide
decision making.
bit.ly/GreenInfrastructureBenefits
46 TACKLING BARRIERS TO GREEN INFRASTRUCTURE
The Value of Green Infrastructure for Urban Climate Adaptation. Center for Clean Air Policy, 2011.
Identifies benefits of green infrastructure to communities to manage extremes in precipitation and temperature.
bit.ly/UrbanClimateAdapt
Financing and Implementation of Green Infrastructure
Getting to Green: Paying for Green Infrastructure: Financing Options and Resources for Local Decision-Makers. U.S. Environmental Protection
Agency, 2014.
Helps municipalities develop financial strategies and identify funding opportunities for green infrastructure.
bit.ly/PayingforGreen
Green Infrastructure Opportunities that Arise During Municipal Operations. U.S. Environmental Protection Agency, 2015.
Uses case studies to demonstrate how green infrastructure can be integrated into public works projects and includes discussion of cost and
benefits, review plans and maintenance.
bit.ly/EPANEP
Managing Stormwater in Redevelopment and Greenfield Development Projects Using Green Infrastructure Economic Factors that Influence Developers’
Decisions. ECONorthwest, 2011.
Covers stormwater management regulations and their impact on greenfield and redevelopment projects from the point of view of the developer.
bit.ly/ManagingStormwater
Reducing Stormwater Costs through Low Impact Design Strategies and Practices. U.S. Environmental Protection Agency, 2007.
Includes 17 case studies of developments that incorporated low-impact development, reduced project costs and improved environmental
performance.
bit.ly/ReducingStormwaterCosts
Maintenance
Elements of a Green Infrastructure Maintenance Business Plan
U.S. Environmental Protection Agency, 2015.
This U.S. EPA report reflects findings from Milwaukee Metropolitan Sewerage District and local stakeholders regarding the suitability of
different business models for conducting maintenance for developing a regional green infrastructure maintenance program.
bit.ly/MaintenanceBusinessPlan
Green City, Clean Waters: Green Infrastructure Maintenance Manual Development Process Plan. Philadelphia Water Department, 2012.
This plan outlines the process of developing a green infrastructure maintenance manual, including evaluating maintenance protocols, devel-
oping protocols, checklists and schedules; maintenance contract agreements; program evaluation; and budget development.
bit.ly/GreenCityCleanWaters
TACKLING BARRIERS TO GREEN INFRASTRUCTURE 47
Staying Green: Strategies to Improve Operations and Maintenance of Green Infrastructure in the Chesapeake Bay Watershed. American Rivers.
This report examines some of the major barriers to effective operations and maintenance of green infrastructure practices in the Chesapeake
Bay region and identifies strategies and best practices that local governments, practitioners and other groups are using to develop and improve
maintenance practices.
bit.ly/StayingGreen
Green Stormwater Operations and Maintenance Manual. Seattle Public Utilities, 2009.
This Seattle Public Utilities manual summarizes routine maintenance activities for the design of Natural Drainage System (NDS) Projects and
includes a chart for scheduling and performing maintenance activities and images and descriptions for vegetation, hardscape, infrastructure and
infiltration rates.
bit.ly/GreenStormwater
The Importance of Operation and Maintenance for the Long-Term Success of Green Infrastructure. U.S. Environmental Protection Agency, 2013.
This report examines the operation and maintenance practices of 22 green infrastructure and highlights opportunities and challenges associated
with green infrastructure O&M.
bit.ly/LongTermSuccess
48 TACKLING BARRIERS TO GREEN INFRASTRUCTURE
REFERENCES
Demuzere et al., 2014. Mitigating and
Adapting to Climate Change: Multi-
functional and Multi-scale Assessment
of Green Urban Infrastructure. Journal of
Environmental Management 146:107-115.
Lee and Maheswaran, 2011. The Health
Benefits of Urban Green Spaces: A
Review of the Evidence. Journal of
Public Health 33(2):212 –222.
Lee et al., 2014. Mitigation of Urban Heat
Island Effect and Greenroofs. Indoor
and Built Environment 23(1): 62–69.
Martin Jaffe et al., 2010. The Illinois
Green Infrastructure Study. Illinois
Environmental Protection Agency.
Milwaukee Metropolitan Sewerage
District, 2005. Surface and Stormwater
Rules Guidance Manual, Appendix L: Low
Impact Development Documentation.
Milwaukee Metropolitan Sewerage
District, 2012. Determining the
Potential of Green Infrastructure to
Reduce Overflows in Milwaukee.
Milwaukee Metropolitan Sewerage District,
2012. Sustainable Water Reclamation.
Milwaukee Metropolitan Sewerage District,
2014. Rules and Regulations, Chapter 13:
Surface Water and Storm Water. Milwaukee
National Recreation and Park
Association, 2010. Air Quality
Effects of Urban Trees and Parks.
New York State Energy Research
and Development Authority, 2006.
Mitigating New York City’s Heat Island
With Urban Forestry, Living Roofs,
and Light Surfaces. Final Report.
Philadelphia Water Department,
2011. Green City Clean Waters: The
City of Philadelphia’s Program for
Combined Sewer Overflow Control
Program Summary (amended).
Sands and Chapman, 2011. Why Green
Infrastructure and I/I Control Go Hand
in Hand, WaterWorld. Retrieved from
bit.ly/WhyGreenInfrastructure.
Tzoulas et al., 2007. Promoting Ecosystem
and Human Health in Urban Areas Using
Green Infrastructure: A Literature Review.
Landscape and Urban Planning 81:167–178.
U.S. EPA, 2002. National Water Quality
Inventory, 2000 report. EPA-841-R-02-001.
U.S. EPA, 2010. Green Infrastructure Case
Studies: Municipal Policies for Managing
Stormwater With Green Infrastructure.
U.S. EPA, 2014. Greening CSO
Plans: Planning and Modeling
Green Infrastructure for Combined
Sewer Overflow (CSO) Control.
U.S. EPA. Implementing Clean Water
Act Section 303(D): Impaired Waters
and Total Maximum Daily Loads
(TMDLs). US EPA. Retrieved December
1, 2015, from www.epa.gov/tmdl.
U.S. EPA, 2008. Incorporating Green
Infrastructure Concepts Into Total
Maximum Daily Loads (TMDLs).
U.S. EPA. Stormwater Runoff - Effective
vs. Total Imperviousness, CADDIS:
Sources, Stressors & Responses. Retrieved
December 1, 2015, from bit.ly/CADDIS.
Wisconsin Department of Natural
Resources, 2014, 2004. Storm Water
Post-construction Technical Standards,
Conservation Practice Standard 1004,
Bioretention for Infiltration; Conservation
Practice Standard 1003, Infiltration Basin.
TACKLING BARRIERS TO GREEN INFRASTRUCTURE 49
Reed Street Yards eco-industrial zone, Milwaukee
50 TACKLING BARRIERS TO GREEN INFRASTRUCTURE
FOOTNOTES
1 Systems include shared parking formulas,
sample agreements and recording docu-
ments. These can ensure that as shared or
off-site parking plans are developed they
will be consistent with what is already
acceptable to the municipal attorney
and the burden is not on the applicants
to develop these documents, which can
make the cost and uncertainty go up
significantly.
2 State regulatory agencies, such as the
Wisconsin Department of Natural
Resources, provide technical standards
and guidance for permeable surfacing.
See Appendix 2. Green Infrastructure
Resources.
3 Vegetated swales are graded, open and
shallow engineered channels that help
reduce peak stormwater discharge flow
volumes and rates. The design of swales
promotes the conveyance of stormwater
at a slower, controlled rate and allows
them to act as a filter medium, removing
pollutants and allowing stormwater infil-
tration. Swales must be carefully designed
and maintained to function properly.
The vegetation is typically made up of
flood-tolerant, erosion-resistant plants,
such as thick grass.
4 The underdrain, standpipe and weir are
filtration design parameters that ensure
sufficient rapid drawdown of water within
the bioretention practice if it were to
become clogged or blocked. This safe-
guards against flooding, and subsequently,
the possible death of the plants within the
bioretention practice.
5 The engineered soil is the growing
medium for plants in the bioretention
practice. Sand and compost were specified
to provide well-drained nutrient-enriched
soil. Engineered soil infiltration rate was
assumed to be 3.6 inches per hour with a
void ratio of 0.27.
6 Rock is placed under the engineered soil
to serve as a storage area for stormwater
to reduce peak flows, store the water to
allow infiltration and allow for the filtra-
tion of solids. Void ratio in stone storage
was assumed to be 0.33.
7 Landscaped areas represent 26% of the
total office park source area.
8 The addition of 5,700 square feet of
bioretention in place of turf grass results
in further reductions in runoff volume and
total suspended solids (48% and 60.4%,
respectively).
9 Adapted from Milwaukee Metropolitan
Sewerage District Surface & Storm
Water Rules Guidance Manual,
Appendix L: Low Impact Development
Documentation (24).
10 Adapted from Wisconsin Department
of Natural Resources Conservation
Practice Standard 1004, Bioretention
for Infiltration; Conservation Practice
Standard 1003, Infiltration Basin (25).
11 Adapted from Milwaukee Metropolitan
Sewerage District Surface & Storm
Water Rules Guidance Manual,
Appendix L: Low Impact Development
Documentation (24).
12 Adapted from Milwaukee Metropolitan
Sewerage District Surface & Storm
Water Rules Guidance Manual,
Appendix L: Low Impact Development
Documentation (24).
13 Adapted from Milwaukee Metropolitan
Sewerage District Rules and Regulations,
Chapter 13: Surface Water and Storm
Water (26).
14 Adapted from Milwaukee Metropolitan
Sewerage District Surface & Storm
Water Rules Guidance Manual,
Appendix L: Low Impact Development
Documentation (24).
15 Adapted from Milwaukee Metropolitan
Sewerage District Surface & Storm
Water Rules Guidance Manual,
Appendix L: Low Impact Development
Documentation (24).
TACKLING BARRIERS TO GREEN INFRASTRUCTURE 51
Tackling Barriers to Green Infrastructure: An
Audit of Municipal Codes and Ordinances
project team included:
Julia Noordyk, University of Wisconsin Sea
Grant Institute, project manager, co-editor
Kate Morgan, formerly, 1000 Friends of
Wisconsin, principal author
Juli Beth Hinds, Orion Planning and
Design, Code Audit Tool author, co-editor
Timothy Detzer, Milwaukee County
Department of Transportation and Public
Works, SWAT modeling
Steve Hiniker, retired, 1000 Friends of
Wisconsin, foreword, technical review
Benjamin Benninghoff, Bryan Hartsook
and Mark Riedel, Wisconsin Department of
Natural Resources, technical review
Bre Plier and Karen Sands, Milwaukee
Metropolitan Sewerage District, technical
review
Jeffrey Nettesheim, Village of Menomonee
Falls, technical review
Matthew Maederer, Village of Brown Deer,
technical review
Moira Harrington, Elizabeth White and
Marie Zhuikov, University of Wisconsin Sea
Grant Institute, editors
Yael Gen, University of Wisconsin Sea
Grant Institute, design
Kevin J. Miyazaki, photography
Production of this workbook was funded
by the National Oceanic and Atmospheric
Administration Coastal Storms Program
and University of Wisconsin Sea Grant
Institute in partnership with 1000 Friends of
Wisconsin, Orion Planning and Design and
Milwaukee Metropolitan Sewerage District.
ACKNOWLEDGMENTS
This workbook would not have been possible
without the dedicated work and expertise
of Kate Morgan (formerly 1000 Friends
of Wisconsin) and Juli Beth Hinds (Orion
Planning and Design). Kate’s vision of
engaging and working one-on-one with
communities to implement green infra-
structure is a central part of what makes this
project a success. In addition to Juli Beth’s
extensive knowledge of water resources and
planning, she created an audit tool that is
relevant and helps communities to navi-
gate the complex landscape of local code
and ordinances.
We would also like to recognize contribu-
tions from Timothy Detzer (Milwaukee
County) and Bryan Hartsook (Wisconsin
Department of Natural Resources) who
were instrumental in the production of the
“What’s the Impact?” section. In addition,
we would like to acknowledge the members
of the Technical Advisory Review Team who
provided their time and invaluable feedback
on this workbook.
The University of Wisconsin Sea Grant
Institute offers gratitude to the partners
involved in creating this workbook.
52 TACKLING BARRIERS TO GREEN INFRASTRUCTURE
Menomonee Valley Redevelopment and Community Park, native plantings, Milwaukee
AUDIT TOOL“Examine each question in terms of what is ethically and aesthetically right, as well as
what is economically expedient. A thing is right when it tends to preserve the integrity,
stability, and beauty of the biotic community. It is wrong when it tends otherwise.”
— Aldo Leopold, A Sand County Almanac and Sketches Here and There
CONTENTS USING THE AUDIT TOOL A 1
YOUR GREEN INFRASTRCUTURE AUDIT A 3
EXAMPLE OF GRADING MATRIX CLASSIFICATIONS A 4
EXAMPLE OF COMPLETED AUDIT TOOL QUESTIONS A 5
ARCHITECTURAL DESIGN STANDARDS A 8
COASTAL COMMUNITIES A 11
COMMUNITY OUTREACH AND EDUCATION A 14
CONSTRUCTION AND POST-CONSTRUCTION MANAGEMENT A 17
LANDSCAPING A 21
PARKING A 29
PERMEABLE MATERIALS A 35
POLLUTANT REDUCTION THROUGH SITE PLAN REVIEW A 38
POST-CONSTRUCTION STORMWATER STANDARDS AND
LONG-TERM MAINTENANCE A 42
PUBLIC WORKS STANDARDS A 45
PURPOSE STATEMENTS AND COMMUNITY PLANS A 50
SANITARY AND STORM SEWER DISCONNECTIONS A 52
STORMWATER MANAGEMENT STANDARDS A 54
SUBDIVISIONS AND NEW “GREENFIELD” DEVELOPMENT A 59
ZONING A 63
A 1GREEN INFRASTRUCTURE AUDIT TOOL
USING THE AUDIT TOOL
Questions related to impervious surfacing
requirements — parking standards, roadway
widths, public safety access areas, etc. —
are also included in the audit because the
reduction of impervious surfaces and effec-
tive impervious areas reduces the volume
of stormwater that must be managed, and
can significantly improve water quality in a
community’s rivers and streams.
The audit also includes questions regarding
supplemental standards and review require-
ments for conditional or “hot spot” land
uses. These are land uses that have a higher
potential to contribute to stormwater runoff
pollution and include animal-related facil-
ities; establishments producing grease and
food waste; contractor and municipal yards
with outdoor storage areas; landscaping and
garden centers with outdoor use of water,
pesticides and fertilizers; and gas stations
and any type of vehicle repair or fueling
station. Stormwater runoff from these types
of land uses can be a significant source of
bacteria and pathogens, sediment, nutri-
ents and toxic chemicals, but this can be
addressed through site plan standards and
stormwater treatment practices.
Each section of the audit tool addresses a
key code and ordinance topic area where
green infrastructure and impervious
surfacing barriers are found. The topic areas
are:
■■Architectural Design Standards
■■Coastal Hazards
■■Community Outreach and Education
■■Construction and Post-Construction
Management
■■Landscaping
■■Parking
■■Permeable Materials and Surfacing
■■Pollutant Reduction Through Site Plan
Review
■■Post-Construction Stormwater
Standards and Long-Term Maintenance
■■Public Works Standards
■■Purpose Statements and Community
Plans
■■Sanitary and Storm Sewer
Disconnections
■■Stormwater Management Standards
■■Subdivisions and New “Greenfield”
Development
■■Zoning
The goals of the audit tool are:
1. Identify regulations that directly prohibit
or are ambiguous, contradictory or silent
on the use of green infrastructure practices
2. Identify regulations pertaining to parking,
frontage and streetscapes that could be
updated and amended to reduce imper-
vious surfacing requirements
3. Identify conditional uses in zoning
districts that are potential sources of
stormwater pollution and determine if
additional standards are in place to protect
water quality
A2 GREEN INFRASTRUCTURE AUDIT TOOL
Scoring
You will answer questions about your codes and ordinances to deter-
mine if they are preventing green infrastructure implementation or
resulting in the spread of impervious surfaces.
While a clear “yes,” “no” or “question” response would be ideal,
in practice, an answer to a question is often more nuanced. For
example, a “yes” response may be dependent upon staff approval. You
are also likely to find a practice that is permitted in one section is
contradicted in a different section of the regulations. For example,
pervious pavement might be allowed in one section of the code, but
in another, all paved surfaces are required to be seal coated, which
cancels any benefit of using permeable material. The scoring matrix
(A+, A, A-, B, C, D, F) was developed to help identify code nuances
and internal conflicts.
Using the scoring matrix, you will indicate whether a code, policy or
operation is creating a barrier with regard to green infrastructure. The
code language is considered a barrier to green infrastructure imple-
mentation if it:
■■Contains language prohibiting or unintentionally discouraging
the use of a green infrastructure practice;
■■Includes ambiguous or unclear language about the use of a green
infrastructure practice;
■■Is silent on the topic or practice with no statement that identifies
green infrastructure as a potential, acceptable practice; or
■■Allows a practice in one area of the code but prohibits or
disallows in another.
An example of grading classifications and a completed audit
section follows.
The barrier column indicates where you could
encounter a barrier in the community’s codes
and ordinances. This could include a type of
code, policy or specific operational code. It may
be necessary to check several areas within the
code to determine if a practice is fully enabled or
if it is restricted by other sections of the code.
Tips give context and suggestions on
how to approach the audit question.
Use this column to note
code references and language
that you find related to the
audit question.
Use the notes, ideas and strategies column
to write down suggestions for overcoming
code barriers or improving language.
Assign the audit question a grade by using the
scoring matrix. Compile the grades in the report
card at the end of the audit to help you identify
areas of the code where barriers exist.
Are there supplemental provisions for protecting or buffering wetlands that are above state requirements?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Subdivision
Planned unit development
Supplemental regulations
Many communities require additional
setbacks and/or demarcation with fencing
or plantings along wetland buffers.
A+
Practice is enabled and described
specifically; clearly allowed and
approved as-of-right
A
Practice is specifically allowable/
as-of-right approval, but some ambi-
guity or potential conflict
A−Practice is enabled or encouraged,
with discretionary approval
B Practice is mentioned but without
standards or guidance for use
C No policy or standards adopted, but
not disallowed
D
Limitations or prohibitive language
in the code, but could potentially be
approved
F
Practice prohibited by code language,
or an active conflict would prevent
approval
YOUR GREEN INFRASTRUCTURE AUDIT
The scoring matrix helps indicate whether a code, policy or
operation is enabling, conditional, ambiguous, discouraging
or conflicted with regards to green infrastructure. An
example of an audit question and grading follows.
Most local regulations are available online and can be
downloaded as a document. As you use the audit tool to work
through the codes and ordinances, highlight the language
in the particular regulation for potential amendment and
make note of it on the audit tool for easy reference.
Record your grades on the report card in this book or
download a copy at gowisc.edu/greenreportcard.
A 3GREEN INFRASTRUCTURE AUDIT TOOL
A4 GREEN INFRASTRUCTURE AUDIT TOOL
EXAMPLE OF SCORING MATRIX CLASSIFICATIONS
Examples of code language for each classification and [justification or explanation of scoring]
Do parking lot edge landscaping requirements (islands and edges) specifically allow or encourage use as stormwater control areas?
Is a standard adopted?
Grade Classification Details and comments
A+
Practice is enabled and
described specifically;
clearly allowed and approved
as-of-right
Perimeter landscape areas shall be designed and installed to function as stormwater management areas or, where not
required for stormwater management, to provide naturalized landscaping. A combination of vertical features such as
green walls and fencing, along with a mix of plantings, shall be used to provide sufficient visual screening of the parking
lot area. [Landscape areas are clearly intended to be designed for stormwater management function.]
A
Practice is specifically allow-
able/as-of-right approval, but
some ambiguity or potential
conflict
The use of perimeter landscape areas to infiltrate and treat stormwater is strongly encouraged; however, the plan
commission shall require at a minimum one tree or woody shrub every ten (10) linear feet within the perimeter landscape
area. [Encourages use of landscaping for stormwater management, but requires woody plantings at specific intervals
that could conflict with bioretention designs.]
A−
Practice is enabled or encour-
aged, with discretionary
approval
The use of perimeter landscape areas for bioretention, swales or other stormwater may be approved by the plan
commission so long as the visual screening intent of this Section is accomplished through a combination of fencing,
tree planting and vegetation. [The plan commission has discretionary approval (may or may not approve) and the listed
standards for what the applicant must accomplish are not specific.]
B
Practice is mentioned but
without standards or guidance
for use
Portions of perimeter landscape areas may be designed as swales if approved by the plan commission. [Approval is
discretionary and standards for what situations would be approvable are not specified.]
C
No policy or standards adopted,
but not disallowed
Perimeter landscape areas shall be designed to accomplish 75% opacity within two years of planting. [While it can be
difficult to design a perimeter landscape as a bioretention area and to achieve 75% opacity, it is potentially allowable.]
D
Limitations or prohibitive
language in the code, but could
potentially be approved
Perimeter landscape buffers shall be comprised of landforms, lawn areas, ground cover, shade trees, flowering trees,
evergreen trees, shrubs and flowers. [While stormwater management or bioretention is not specifically prohibited,
neither bioretention nor ‘grasses’ are listed; language “shall be” often interpreted to mean that no plantings or uses are
allowed other than those listed.]
F
Practice prohibited by code
language, or an active conflict
would prevent approval
Perimeter landscape areas shall be graded into a berm or landform with a minimum slope of 2:1 topped by a planting
plan that will form a dense evergreen screen within two years of planting. [Does not allow for water inflow or
native plantings.]
A 5GREEN INFRASTRUCTURE AUDIT TOOL
EXAMPLE OF COMPLETED AUDIT TOOL QUESTIONS
An example of a completed Architectural Design Standard section of the audit tool
Are rainwater-harvesting and stormwater-control elements acknowledged in design standards?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Design guidelines
Architectural standards
Include illustrations or definitions of green
roofs, planter boxes and cisterns; this
ensures reviewers and designers will
know that these elements are allowed
or encouraged.
None. No mention of “rain
barrel” or “cistern”
anywhere in our municipal
code, zoning or historic
district, but it doesn’t say
that they are not allowed.
Zoning administration hasn’t
had complaints but wonders
if they’re legal within the
required setbacks.
[Select B for “not
mentioned, not prohibited.”]
Add to the list of accessory
structures in Section 24.3
that are exempt from zoning
permits and setbacks, “a
maximum of two rain barrels
or cisterns up to 100
gallons each.”
Ask at landscape center
whether people have
requested or bought larger
rainwater tanks.
Discuss if bigger tanks
should require plan commis-
sion review during upcoming
meeting on misc. zoning
issues.
B
Are green infrastructure practices suitable for high-density areas (e.g., planter boxes, cisterns) allowed to extend into the right-of-way or onto
sidewalks?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Municipal code
Design guidelines
Architectural standards
Table of dimensional
standards
Most zoning ordinances specify what
elements, like awnings or signs, may
extend into the public right-of-way. Planter
boxes and cisterns often need to be
added to this list and allowed to extend
at least 24 inches into the right-of-way or
other setbacks.
Village Code Chapter 8.3(b)
states, “No portion of
any building or struc-
ture may extend into the
right-of-way.”
Zoning administration says
a structural planter box
might be allowed if trustees
approved it but isn’t sure.
[Select D for “prohibitive
language, but possible
option for approval.”]
Ask university extension
staff for photos of planter
boxes along village street
and in other communities so
the Architectural Advisory
Committee can see what
these look like and make a
recommendation.
D
A6 GREEN INFRASTRUCTURE AUDIT TOOL
Do design standards allow siting of stormwater-control measures along façade?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Design guidelines
Architectural standards
Zoning setbacks
Zoning often will limit the structures that
can be attached to a building façade or
located within a setback. Codes should
specify that rain barrels or cisterns and
planter boxes may be sited along façades
or extend into setbacks.
Village Design Guidelines
show photos and illustra-
tions of planter boxes along
façades, but they don’t say
that they’re for “stormwater
control” or give allowable
dimensions.
[Select A- for “allowable,
but no specific guidance or
standards.”]
In our next revision,
add a note to the Design
Guidelines that states:
“Planter boxes are designed
to treat stormwater runoff
and approval by the village
engineer is encouraged.”
Have the municipal planner
make a note that planter
boxes should be encouraged
when talking to applicants.
A-
Do standards allow for the waiver of design or architectural provisions to accommodate stormwater-control measures (planters, cisterns, green
roofs, etc.)?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Design guidelines
Architectural standards
Zoning setbacks
Where a community provides for waivers
of architectural standards, “siting of green
infrastructure measures” should be a
specific reason for the grant of a waiver.
The Historic Overlay
District prohibits “non-his-
toric features” from being
attached to any building
façade or sited in a front
yard.
[Select D for “limitations
or prohibitive language in
the code, but could poten-
tially be approved.”]
Could argue that rain barrel
was used historically and
not as limiting as “rain
barrels shall not...”
Add language allowing
waivers from historic
standards or roof design
upon compatibility review
by a design or historic
commission.
D
EXAMPLE OF COMPLETED AUDIT TOOL QUESTIONS (continued)
A 7GREEN INFRASTRUCTURE AUDIT TOOL
Are pitched roofs required? If so, is a waiver or provision for green roofs or rainwater harvesting made?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Design guidelines
Architectural standards
Zoning setbacks
If design standards require pitched roofs
of a certain slope (i.e., 3:1) or for buildings
to match adjacent roof pitches, some
allowance for changing pitch should be
made for rainwater harvesting or green
roof installation.
Design standards require
new buildings to “match
the prevailing roof pitch
and design of the adjacent
structures” or to have a
minimum pitch.
Select D for “limitations or
prohibitive language in the
code, but could potentially
be approved.”]
Add language allowing a
waiver where the review
board finds that the intent
of the regulations is met.
Consult with a local archi-
tect on how to illustrate
a compatible design that
doesn’t “match” the roof
pitch.
D
Are green infrastructure practices suitable for high-density areas allowed or encouraged in streetscapes (e.g., tree boxes, sidewalk bioretention
areas, curb bump-outs)?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Design guidelines
Streetscape standards
Architectural standards
Streetscape standards often need amend-
ments to specifically enable stormwater
trees, sidewalk bioretention or curb
bump-outs to be included in renovated or
new streets.
The streetscape for all
new buildings in a commer-
cial sub-district requires a
specific pattern of concrete
sidewalk and curbing at the
end of each block.
[Select F for “Practice
prohibited by code language,
or an active conflict would
prevent approval.” Would
likely require a code change
to achieve.]
Cannot deviate from the
adopted standard that
precludes incorporation of
green or vegetated features.
Add a supplemental illus-
tration and text showing an
option for a curb bump-out
that incorporates plantings
and bioretention. Provide
these alternatives to the
city engineer for review.
F
EXAMPLE OF COMPLETED AUDIT TOOL QUESTIONS (continued)
A8 GREEN INFRASTRUCTURE AUDIT TOOL ARCHITECTURAL DESIGN STANDARDS
Are rainwater-harvesting and stormwater-control elements acknowledged in design standards?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Design guidelines
Architectural standards
Include illustrations or definitions of green
roofs, planter boxes and cisterns; this
ensures reviewers and designers will
know that these elements are allowed
or encouraged.
Are green infrastructure practices suitable for high-density areas (e.g., planter boxes, cisterns) allowed to extend into the right-of-way
or onto sidewalks?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Municipal code
Design guidelines
Architectural standards
Table of dimensional
standards
Most zoning ordinances specify what
elements, like awnings or signs, may
extend into the public right-of-way. Planter
boxes and cisterns often need to be
added to this list and allowed to extend
at least 24 inches into the right-of-way or
other setbacks.
ARCHITECTURAL DESIGN STANDARDS
Design guidelines, architectural standards, streetscape designs and specific dimensional standards in zoning may need to be modified to enable green infrastructure
practices. Reviewing standards with an eye to whether practices such as planter boxes, curb bump-outs, rainwater harvesting cisterns or green roofs would be allowed can
highlight areas that may need revision.
A 9GREEN INFRASTRUCTURE AUDIT TOOLARCHITECTURAL DESIGN STANDARDS
Do design standards allow siting of stormwater-control measures along façade?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Design guidelines
Architectural standards
Zoning setbacks
Zoning often will limit the structures that
can be attached to a building façade or
located within a setback. Codes should
specify that rain barrels or cisterns and
planter boxes may be sited along façades
or extend into setbacks.
Do standards allow for the waiver of design or architectural provisions to accommodate stormwater-control measures (planters, cisterns, green
roofs, etc.)?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Design guidelines
Architectural standards
Zoning setbacks
Where a community provides for waivers
of architectural standards, “siting of green
infrastructure measures” should be a
specific reason for the grant of a waiver.
Are pitched roofs required? If so, is a waiver or provision for green roofs or rainwater harvesting made?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Design guidelines
Architectural standards
Zoning setbacks
If design standards require pitched roofs
of a certain slope (i.e., 3:1) or for buildings
to match adjacent roof pitches, some
allowance for changing pitch should be
made for rainwater harvesting or green
roof installation.
A10 GREEN INFRASTRUCTURE AUDIT TOOL ARCHITECTURAL DESIGN STANDARDS
Are green infrastructure practices suitable for high-density areas allowed or encouraged in streetscapes (e.g., tree boxes, sidewalk bioretention
areas, curb bump-outs)?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Design guidelines
Streetscape standards
Architectural standards
Streetscape standards often need amend-
ments to specifically enable stormwater
trees, sidewalk bioretention or curb
bump-outs to be included in renovated or
new streets.
A 11GREEN INFRASTRUCTURE AUDIT TOOLCOASTAL COMMUNITIES
COASTAL COMMUNITIES
Located at the end of the watershed “pipe,” coastal communities face unique challenges related to stormwater management, including beach swimming advisories, excess
nutrients and eutrophication, and coastal erosion. Taking a look at local codes and ordinances that deal with stormwater outfalls, ravine and bluff protection, and erosion
control can help reduce the amount of sediment and contaminants entering coastal areas.
Is protection of bluffs and ravines described in the Comprehensive Plan and ordinance?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Comprehensive plan
Zoning
Special purpose
ordinance
Provide a policy basis in the comprehen-
sive plan that supports the adoption and
revision of standards, such as, “Adopt
setbacks and planting standards that
will lead to the creation of a buffer along
vulnerable bluffs and ravines.”
Are there review procedures over and above other code provisions for activities in proximity to bluffs and ravines?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Comprehensive plan
Zoning
Special purpose
ordinance
Requiring setbacks for new or expanded
structures and impervious surfaces, and
limitations on clearing or grading where
erosion could be exacerbated are common
provisions of a bluff and ravine protection
ordinance.
Grades:
A12 GREEN INFRASTRUCTURE AUDIT TOOL COASTAL COMMUNITIES
Are there provisions or setbacks from bluffs and ravines for new or expanded structures?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Comprehensive plan
Zoning
Special purpose
ordinance
Requiring setbacks for new or expanded
structures and impervious surfaces, and
limitations on clearing or grading where
erosion could be exacerbated are common
provisions of a bluff and ravine protection
ordinance.
Are there provisions or setbacks from bluffs and ravines for new impervious surfaces?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Comprehensive plan
Zoning
Special purpose
ordinance
Requiring setbacks for new or expanded
structures and impervious surfaces, and
limitations on clearing or grading where
erosion could be exacerbated are common
provisions of a bluff and ravine protection
ordinance.
Are there provisions on clearing and grading near bluffs and ravines?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Comprehensive plan
Zoning
Special purpose
ordinance
Requiring setbacks for new or expanded
structures and impervious surfaces, and
limitations on clearing or grading where
erosion could be exacerbated are common
provisions of a bluff and ravine protection
ordinance.
A 13GREEN INFRASTRUCTURE AUDIT TOOLCOASTAL COMMUNITIES
Can foundation drain, roof leaders or sump pump discharges be sited where discharge will exit on the slope of a bluff or ravine? What is the
review process, if any?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Comprehensive plan
Zoning
Special purpose
ordinance
Ensuring some review of clear water
discharges can identify cases where
relocation or re-direction to a permeable
or vegetated area may provide better
protection against erosion.
Has the community identified stormwater outfalls flowing directly onto beaches or into streams that flow directly to beaches?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Comprehensive plan
Zoning
Special purpose
ordinance
Identification of outfall locations and
contributing drainage areas helps prioritize
investments in stormwater improvements.
A14 GREEN INFRASTRUCTURE AUDIT TOOL COMMUNITY OUTREACH AND EDUCATION
COMMUNITY OUTREACH AND EDUCATION
Local activities and investments also support implementation of green infrastructure. Pilot projects, education and training for boards, and staff training on handling inquiries
about downspout disconnection or rain barrels are all important parts of a green infrastructure strategy.
Is there a local ordinance or policy limiting the application of pesticides or herbicides on public property?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Municipal policy
Staff knowledge
Pesticides and herbicides can affect
soil function and capacity to absorb
water and pollutants. Many communities
have adopted policies or procedures
limiting the use of pesticides and herbi-
cides for noxious and invasive plants to
spot treatments.
Has green infrastructure education been provided to staff involved in plan reviews? This includes staff in public safety, engineering, parks and
recreation, economic development, and planning and zoning.
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Municipal policy
Staff knowledge
Training staff, appointed boards and
elected officials helps provide a common
base of knowledge about green infrastruc-
ture techniques and their applicability in
this climate and region.
A 15GREEN INFRASTRUCTURE AUDIT TOOLCOMMUNITY OUTREACH AND EDUCATION
Has green infrastructure education been provided to planning boards and elected officials?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Municipal policy
Staff knowledge
Training staff, appointed boards and
elected officials helps provide a common
base of knowledge about green infrastruc-
ture techniques and their applicability in
this climate and region.
Has a rain barrel or rain garden pilot program been done in your community?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Municipal policy
Staff knowledge
Pilot projects allow the public to visit
and “see for themselves” how green
infrastructure techniques look and work
once installed.
Is a review or procedure in place for rain garden construction and planting native plants in yards and lawns?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Municipal policy
Staff knowledge
Having a written procedure (even if not
formally adopted) for common requests
greatly facilitates both the use of these
techniques and managing neighbor
inquiries and public concerns. It is equally
important to ensure that all staff know to
transfer questions to a knowledgeable
person or department.
A16 GREEN INFRASTRUCTURE AUDIT TOOL COMMUNITY OUTREACH AND EDUCATION
Is a review or procedure in place for downspout disconnection and rain barrel installation?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Municipal policy
Staff knowledge
Having a written procedure (even if not
formally adopted) for common requests
greatly facilitates both the use of these
techniques and managing neighbor
inquiries and public concerns. It is equally
important to ensure that all staff know to
transfer questions to a knowledgeable
person or department.
Is a review or permit process in place to facilitate the disconnection of foundation drains?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Municipal policy
Staff knowledge
Having a written procedure (even if not
formally adopted) for common requests
greatly facilitates both the use of these
techniques and managing neighbor
inquiries and public concerns. It is equally
important to ensure that all staff know to
transfer questions to a knowledgeable
person or department.
Who answers inquiries and what is his or her level of knowledge?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Municipal policy
Staff knowledge
Having a written procedure (even if not
formally adopted) for common requests
greatly facilitates both the use of these
techniques and managing neighbor
inquiries and public concerns. It is equally
important to ensure that all staff know to
transfer questions to a knowledgeable
person or department.
A 17GREEN INFRASTRUCTURE AUDIT TOOLCONSTRUCTION AND POST-CONSTRUCTION MANAGEMENT
CONSTRUCTION AND POST-CONSTRUCTION MANAGEMENT
Many municipal code provisions relate to how previously open and unbuilt land is managed during and after construction. Construction-phase provisions focus on limiting
erosion and also on preventing damage to trees, plants and soils, all of which maintain natural functions including stormwater control. How open-space areas are planted,
maintained and managed after construction also affects stormwater management and natural functions. It should be considered during development planning and review.
Does the ordinance require or promote preservation of native vegetation at development sites?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Stormwater ordinance
[construction provisions]
Subdivision
Planned unit development
Many planned unit developments or
subdivision provisions encourage or
require areas of well-established or native
vegetation, particularly stands of mature
trees, to be incorporated into reserved
open space or landscaped areas on the
site where possible.
Does the ordinance require or encourage limiting clearing and grading at development sites (e.g., construction-site phasing, clearing limit
demarcation requirements, prohibitions on construction equipment storage)?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Stormwater ordinance
[construction provisions]
Requiring construction phase activities
and limits of disturbance to be identi-
fied is an important and straightforward
measure. Inspections should include limits
of disturbance, tree protection and hydric
soil areas.
A18 GREEN INFRASTRUCTURE AUDIT TOOL CONSTRUCTION AND POST-CONSTRUCTION MANAGEMENT
Are the limits of disturbance shown on site plans required to be physically marked on the construction site?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Stormwater ordinance
[construction provisions]
Requiring construction phase activities
and limits of disturbance to be identi-
fied is an important and straightforward
measure. Inspections should include limits
of disturbance, tree protection and hydric
soil areas.
Does the ordinance include construction-phase inspection of limits of disturbance?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Stormwater ordinance
[construction provisions]
Requiring construction phase activities
and limits of disturbance to be identi-
fied is an important and straightforward
measure. Inspections should include limits
of disturbance, tree protection and hydric
soil areas.
Do site and erosion control plans require identification, site marking and protection of mature trees?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Stormwater ordinance
[construction provisions]
Site plan
Subdivision
Landscape standards
Requiring construction phase activities
and limits of disturbance to be identi-
fied is an important and straightforward
measure. Inspections should include limits
of disturbance, tree protection and hydric
soil areas.
A19GREEN INFRASTRUCTURE AUDIT TOOLCONSTRUCTION AND POST-CONSTRUCTION MANAGEMENT
Are native or hydric soils required to be identified, demarcated and protected from disturbance and construction activity?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Stormwater ordinance
[construction provisions]
In areas where infiltration is needed to
manage stormwater or where soils are
highly erodible, these should be identified
on erosion control plans and specifically
protected from disturbance and compac-
tion during construction.
Are management plans required for open space and conservation areas set aside in development?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Subdivision
Planned unit development
The value of open space areas for habitat,
stormwater management and natural func-
tions is affected by both vegetative cover
(e.g., trees, plantings) and by management
(e.g., mowing, removing invasive plants).
Reviewing a plan for vegetation and
management helps identify opportunities
for resource protection and the level of
maintenance needed.
If open space or conservation areas are required, does a minimum percentage have to be managed in a natural condition (e.g., maintained as
woodland, deep-rooted plantings or native vegetation instead of turf)?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Subdivision
Planned unit development
The value of open space areas for habitat,
stormwater management and natural func-
tions is affected by both vegetative cover
(e.g., trees, plantings) and by management
(e.g., mowing, removing invasive plants).
Reviewing a plan for vegetation and
management helps identify opportunities
for resource protection and the level of
maintenance needed.
A20 GREEN INFRASTRUCTURE AUDIT TOOL CONSTRUCTION AND POST-CONSTRUCTION MANAGEMENT
Are there supplemental provisions for protecting or buffering wetlands that are above state requirements?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Subdivision
Planned unit development
Supplemental regulations
Many communities require additional
setbacks and/or demarcation with fencing
or plantings along wetland buffers.
Has the community identified historic stream channels and waterways? Are any of these features protected from modification or development?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Subdivision
Planned unit development
Stormwater ordinance
Areas where historic stream channels
and ponds have been filled in or modified
are often prone to flooding. They may be
good areas to incorporate into stormwater
management features, open space or
landscaping.
A 21GREEN INFRASTRUCTURE AUDIT TOOLLANDSCAPING
LANDSCAPING
Each landscaping feature can be considered a critically important water quality protection measure. The design and management of “everyday” landscaping features —
including trees, medians, tree lawns, buffer strips, landscaped borders, foundation plantings and how snow storage is handled — can greatly benefit water quality without
adding cost for applicants or municipal projects.
Do preliminary or sketch plans include stormwater measures and landscape techniques for initial review?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Procedures [Site plan,
Planned unit development,
Subdivision]
Early review of land use concepts helps
identify opportunities to integrate green
infrastructure into landscaping and
drainage.
Is a consolidated plan for landscaping, grading/drainage and stormwater-control measures encouraged or required?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Procedures [Site plan,
Planned unit development,
Subdivision]
Stormwater ordinance
Putting grading/drainage and landscaping
plans on the same sheet illustrates where
and how landscaping and stormwater
management can be integrated.
A22 GREEN INFRASTRUCTURE AUDIT TOOL LANDSCAPING
Is the use of deep-rooted or native plants, plants with habitat value, or edibles allowed or encouraged in the landscaping standards?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Landscape standards
Design guidelines
Explicitly listing or illustrating the use of
native plantings, deep-rooted plants or
other alternatives to turfgrass and shrubs
tells site planners up front that the commu-
nity encourages these types of plantings.
Is there a process or standard to waive numerical, spacing and species requirements for stormwater-control measures in required landscape
areas?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Landscape standards
Design guidelines
Specific dimensional standards, such as a
requirement to space trees 25 feet apart,
may conflict with the design of vegetated
stormwater controls. Waivers can allow
variation where needed to accommodate
green infrastructure.
Do visual buffer and screening provisions enable a variation in plantings or substitution of fencing if co-designed for stormwater?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Landscape standards
Design guidelines
Codes often require buffers between
properties or uses be composed of a
“dense evergreen hedge” or similar. Codes
can be modified to provide an option for
integrating vegetated stormwater-control
measures where needed using a combina-
tion of fencing and plants for screen and
buffer areas.
A 23GREEN INFRASTRUCTURE AUDIT TOOLLANDSCAPING
Do vegetated stormwater management areas such as bioretention areas, rain gardens, stormwater trees or other plantings count toward
required landscape minimums?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Landscape standards
Design guidelines
Requiring ornamental landscaping in addi-
tion to bioretention areas or other green
infrastructure is a significant barrier; often,
there will not be enough area on the site to
accommodate both.
Is berming of setback and landscape areas along right-of-ways required and/or habitually preferred as a method of visual screening?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Landscape standards
Street standards
Design guidelines
Requirements for berms will limit or
entirely prevent the use of “edge”
areas and road frontage for stormwater
management.
Are naturalized landscaping standards and requirements promoted for use in stormwater treatment practices?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Stormwater ordinance
Landscape standards
Subdivision
Communities may have standards that
encourage or require naturalized land-
scaping or native plantings in and around
stormwater ponds and swales.
A24 GREEN INFRASTRUCTURE AUDIT TOOL LANDSCAPING
Are there minimum landscaping requirements for parking lots? Perimeters, islands or both (e.g., percentage of parking landscaped, number of
trees per parking spaces, canopy coverage)?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Site plan
Parking standards
Landscape standards
Parking lot landscaping — both perimeter
and island — can mitigate urban heat
island effects and can be co-designed
as green infrastructure for stormwater
treatment.
Is there a minimum size for parking lot landscape islands?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Site plan
Parking standards
Landscape standards
Parking lot islands must be large enough
(typically a 100-square-foot minimum) to
have sufficient soil volume for healthy tree
and plant growth.
Do parking lot edge landscaping requirements (islands and edges) specifically allow or encourage use as stormwater-control areas? Is a
standard adopted?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Site plan
Parking standards
Landscape standards
Actively encouraging the use of islands
and perimeters for green infrastructure
gives important direction to site planners.
A 25GREEN INFRASTRUCTURE AUDIT TOOLLANDSCAPING
Are flush curbs and/or curb cuts allowed to direct runoff into vegetated landscaped islands?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Site plan
Parking standards
Landscape standards
Allowing breaks in curbs or the use of
wheel stops/barriers enables co-design
of islands and perimeters for storm-
water, while also protecting adjacent
landscaping.
Are green walls defined or encouraged? Do they count toward required landscaping?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Landscape standards
Definitions
Design guidelines
Green wall systems are gaining popularity
and have many applications for land-
scaping and screening; some definitions
of “fence” may be too specific to allow
green walls.
Is turfgrass required in new subdivisions or construction? Could deep-rooted plants be substituted?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Subdivision
Landscape standards
Site plan
Stormwater ordinance
[construction provisions]
Subdivision regulations often require
lots to be “sodded.” Standards should
state that native or deep-rooted plantings
may be used, even if temporarily, on new
residential lots.
A26 GREEN INFRASTRUCTURE AUDIT TOOL LANDSCAPING
Do the standards encourage or require that turfgrass be used only for active recreation areas?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Subdivision
Landscape standards
Site plan
Stormwater ordinance
[construction provisions]
In subdivisions or planned unit devel-
opments with common open space, or
large-lot commercial development, limiting
turfgrass to active recreation areas
encourages the use of deeper-rooted
plants and trees that reduce runoff
volumes and sediment loads.
Are snow storage areas required to be shown on site plans?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Subdivision
Landscape standards
Site plan
Stormwater ordinance
[construction provisions]
Snow storage should be required to be
shown on site plan applications. Storage
should be located in areas where melting
and infiltration can occur and spring
residue removed, without affecting the
performance of stormwater treatment
practices or leading to sedimenta-
tion and pollution in adjacent streams
and wetlands.
Is snow storage in bioretention areas prohibited or discouraged, unless the area is specifically designed for snow storage (i.e., grass swales)?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Subdivision
Landscape standards
Site plan
Stormwater ordinance
[construction provisions]
Snow storage should be required to be
shown on site plan applications. Storage
should be located in areas where melting
and infiltration can occur and spring
residue removed, without affecting the
performance of stormwater treatment
practices or leading to sedimenta-
tion and pollution in adjacent streams
and wetlands.
A 27GREEN INFRASTRUCTURE AUDIT TOOLLANDSCAPING
Are street trees required or encouraged along streets (residential, commercial, other or all)?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Site plan
Subdivision
Landscape standards
Public works
specifications
Design guidelines
Street trees help attenuate stormwater
flows and pollutants, especially if planted
in sufficient volumes of well-aerated soils.
This can be specified in a stormwater
management plan.
Are tree lawns and terraces allowed or encouraged to be designed as stormwater treatment areas rather than turfgrass and trees only?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Landscape standards
Public works
specifications
Municipal code
Some tree lawn or terrace areas may be
suitable for use as stormwater manage-
ment areas or can be landscaped with
deeper-rooted plantings. Maintenance
responsibility and an approval procedure
should be specified.
Can landscaped islands for stormwater treatment be created within culs-de-sac or medians?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Public works
specifications
If standard specifications do not allow
for different engineering designs (i.e.,
“all medians shall be composed of…”),
some variance procedure or alternative
standard may be needed.
A28 GREEN INFRASTRUCTURE AUDIT TOOL LANDSCAPING
Are native plantings specifically allowed in front yards or lawn areas?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Municipal code
Nuisance weeds
ordinance
Landscape standards
Consider establishing a written review
or approval procedure, simple standards
requiring demarcation of edging and
bordering with native and deep-rooted
plants and a procedure for mowing if
noxious weeds or lack of maintenance
occurs.
A 29GREEN INFRASTRUCTURE AUDIT TOOLPARKING
PARKING
Measures that allow for reductions in the total impervious area devoted to parking, both through reductions in the total volume of required parking and in the requirements for
landscaping and surfacing, are crucial to reducing stormwater runoff volumes. In addition to the landscaping issues discussed above, zoning regulations govern parking space
sizes and the total number of spaces required on individual development sites, and whether parking can be shared among uses in a building, shopping center or office park.
Do parking ratios reflect current Urban Land Institute or Institute of Transportation Engineers recommended ratios of spaces per square feet of
gross floor area?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Zoning
Off-street parking and
loading standards
Parking ratios should be updated to reflect
recent professional survey data on parking
demand for uses such as restaurants,
medical offices and banks to reflect
changing consumer and worker patterns.
Are the uses in the parking regulations updated to reflect contemporary development types (e.g., drive-through pharmacies, large home
improvement stores) and eliminate outdated ones (e.g., video rental, photo processing, men’s clothiers)?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Zoning
Off-street parking and
loading standards
The table of uses can be reviewed to
incorporate expected types of develop-
ment and eliminate outdated ones, so that
parking requirements are both easy to
administer and not excessive.
Note Vehicle trip end refers to the origin or destination of a vehicle trip (e.g., work commute, grocery run). Each trip has two ends.
A30 GREEN INFRASTRUCTURE AUDIT TOOL PARKING
Are parking ratios set as maximum or median (rather than minimum) requirements?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Zoning
Off-street parking and
loading standards
Many communities set maximum parking
ratios, which effectively prevent “over-
parking.” In some cases, the required
amount of parking is the maximum that
may be built; in others, up to 120% of the
requirement is allowed.
Do dense districts eliminate on-site parking requirements or have reduced requirements?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Zoning
Off-street parking and
loading standards
In downtowns or mixed-use districts
where walking among uses can be
expected, parking ratios per individual use
may be substantially reduced or even elim-
inated, especially if municipal or on-street
parking is available.
Is the parking ratio reduced if shared parking arrangements are in place or multi-modal transit (e.g., mass transit, bike-n-shower facilities) is
provided nearby? (Note distance to transit.)
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Zoning
Off-street parking and
loading standards
Parking ratios can be reduced where
transit access is likely to reduce vehicle
trip ends, or for offices, etc., that provide
storage and other facilities promoting
bicycle commuting.
A 31GREEN INFRASTRUCTURE AUDIT TOOLPARKING
Are there incentives to developers to provide parking within garages rather than surface parking lots [structured parking funded/incentivized
where suitable to zoning district]?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
TIF policy
Zoning
Planned unit development
Development agreements
Is the minimum stall width for a standard parking space 9 feet or less?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Zoning
Off-street parking and
loading standards
Is the minimum stall length for a standard parking space 18 feet or less?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Zoning
Off-street parking and
loading standards
A32 GREEN INFRASTRUCTURE AUDIT TOOL PARKING
Are flexible space sizes and/or compact parking spaces allowed or encouraged? What percentage or limits?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Zoning
Off-street parking and
loading standards
Allowing a certain number or percent of
spaces (often 20% to 25%) to have reduced
sizes and to be labeled “compact” can
reduce total parking surface area.
Is the use of shared parking arrangements promoted?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Zoning
Off-street parking and
loading standards
Encouraging shared parking among uses
in the same building or on the same site is
a key strategy to reduce parking surface
area.
Is a shared parking agreement format, calculation and administration procedure for changes in use in place?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Zoning
Off-street parking and
loading standards
Rather than requiring each applicant to
justify the number of spaces in a shared
parking plan, a table with formulas can
be provided to streamline the process.
Providing a simple format for tracking
changes in use also makes administration
and enforcement easier.
A 33GREEN INFRASTRUCTURE AUDIT TOOLPARKING
Is the use of off-site parking arrangements promoted?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Zoning
Off-street parking and
loading standards
Required parking may be provided on
properties owned by others, provided
an agreement is recorded ensuring that
the spaces will be made available to the
permitted use.
Is an off-site parking agreement or recording document provided or adopted?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Staff knowledge Providing a sample agreement acceptable
to the municipal attorney facilitates admin-
istration and enforcement.
How many off-street parking spaces per residence are allowed or required? How many driveway spaces are allowed or required?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Zoning
Off-street parking and
loading standards
Subdivision
Municipal code
Residential parking requirements affect
the amount of impervious cover on indi-
vidual home sites.
A34 GREEN INFRASTRUCTURE AUDIT TOOL PARKING
Is there a maximum number of cars or area of off-street or driveway parking per single family residence?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Zoning
Off-street parking and
loading standards
Subdivision
Municipal code
Setting a maximum number of vehicles
or off-street spaces can avoid expansive
driveways. Alternatively, any driveway
area above and beyond what is required
for a standard driveway can be required to
be permeable or grasscrete surfacing.
Is there a prohibition on parking on vegetated areas or required yards*?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Zoning
Off-street parking and
loading standards
Subdivision
Municipal code
Allowing vehicles to park on required
yards or vegetated areas results in soil
compaction and reduces infiltration
capacity. Cars and RVs can be required to
be parked on improved or graveled areas.
*A required yard is the area that lies between a property line or right-of-way and an object required to be set back, such as a structure. A yard is more commonly known as a setback.
A 35GREEN INFRASTRUCTURE AUDIT TOOLPERMEABLE MATERIALS
PERMEABLE MATERIALS
Standards for parking, driveways and loading areas tend to be included in zoning, while standards for construction of driveway aprons, streets, alleys, sidewalks and
streetscapes usually are found in public works standards or even municipal code.
Does the municipality have experience with permeable material, curbless streets or other green infrastructure measures?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Local knowledge Taking a group tour to a permeable paving
site or bringing in university or state
departments of natural resources or envi-
ronmental protection staff to talk about
options can help build knowledge.
Are standard specifications or performance standards adopted or referenced for permeable materials?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Public works standards
Local knowledge
Many state departments of natural
resources or environmental protection and
the American Society of Civil Engineers
publish standards that can be referenced
in local standards or codes.
A36 GREEN INFRASTRUCTURE AUDIT TOOL PERMEABLE MATERIALS
Must a sealant be used on improved surfaces, and, if so, can that provision be waived?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Public works standards When adding allowances for permeable
surfacing, communities must ensure that
any requirement for sealants is modified or
waived for permeable surfacing.
Are low-volume street sections allowed or encouraged to be permeable?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Zoning
Subdivision
Public works standards
and specifications
A good place to start can be to write
a general waiver in the code allowing
permeable surfacing “upon review and
approval of the village/city engineer,” or
making an as-of-right allowance in parking
stalls, with other areas allowed with engi-
neering review.
Can parking lanes along streets be constructed with permeable surfacing?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Zoning
Subdivision
Public works standards
and specifications
A good place to start can be to write
a general waiver in the code allowing
permeable surfacing “upon review and
approval of the village/city engineer,” or
making an as-of-right allowance in parking
stalls, with other areas allowed with engi-
neering review.
A 37GREEN INFRASTRUCTURE AUDIT TOOLPERMEABLE MATERIALS
Is the width or total surface area of driveways limited (e.g., as percent of lot area)? Can permeable driveways exceed that limitation?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Zoning (lot coverage or
general regulations)
Public works standards
Many communities limit driveway widths
to 20 feet for residential and 24 feet or 30
feet for non-residential uses, or limited
as a percent of total lot area. In dense
settings, permeable driveways may be
allowed to exceed limits.
Are driveway aprons allowed or encouraged to be permeable?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Zoning (lot coverage or
general regulations)
Public works standards
Many communities require all driveway
aprons to be constructed of concrete. This
can have the effect of prohibiting installa-
tion of French drains at driveway aprons.
A provision ensuring that French drains for
infiltration or permeable surfacing can be
allowed behind the apron can be added to
the code to ensure this important storm-
water reduction option is allowable.
A38 GREEN INFRASTRUCTURE AUDIT TOOL POLLUTANT REDUCTION THROUGH SITE PLAN REVIEW
POLLUTANT REDUCTION THROUGH SITE PLAN REVIEW
A number of uses have the potential to cause polluted runoff unless outdoor areas are properly managed and reviewed. Providing additional review of these uses can be
especially important where TMDLs are in place or where receiving waters are used for swimming, boating and fishing.
Are standards and requirements adopted for trash areas and dumpsters?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Municipal code
Zoning
Supplemental regulations
Conditional use
requirements
Ensuring that trash is covered and fully
contained, with trash storage areas
graded or curbed to drain away from storm
drains and surface waters, both prevents
animals from getting into trash and
prevents polluted runoff.
Are trash/dumpster areas required to have four-sided enclosures?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Municipal code
Zoning
Supplemental regulations
Conditional use
requirements
Effective measures require a four-sided
enclosure with a locking gate rather than
simply “visual screening.”
A 39GREEN INFRASTRUCTURE AUDIT TOOLPOLLUTANT REDUCTION THROUGH SITE PLAN REVIEW
Are trash/dumpster areas required to be covered?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Municipal code
Zoning
Supplemental regulations
Conditional use
requirements
Some communities with swimming
beaches or sensitive water resources
require trash and dumpster area covers,
which reduce the potential for bacterial
transport. Covers are not inexpensive but
are available from commercial suppliers.
Are trash/dumpster areas reviewed for drainage?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Municipal code
Zoning
Supplemental regulations
Conditional use
requirements
A provision can be added to ensure that
drainage from trash and dumpster areas is
generally directed away from storm drains
toward a grass or vegetated area, or at a
minimum that storm drains are not located
directly under dumpsters.
Are there supplemental standards for potentially polluting uses?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Municipal code
Zoning
Supplemental regulations
Conditional use
requirements
Better trash and outdoor area manage-
ment at any business or activity that
handles food or animals, such as dog
day care centers or restaurants, can
reduce bacteria, grease/oil and nutrient
loads to the storm drain system. See the
“Stormwater Pollution Prevention for
Restaurants” video at go.wisc.edu/ok7974.
A40 GREEN INFRASTRUCTURE AUDIT TOOL POLLUTANT REDUCTION THROUGH SITE PLAN REVIEW
Are there standards for gas and auto repair stations?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Municipal code
Zoning
Supplemental regulations
Conditional use
requirements
Auto-related uses should be reviewed
to ensure fueling or repair areas meet
published standards, and no potentially
polluting materials such as washer fluids,
oil or parts are stored outside unless
completely covered.
Are there standards for food-related uses?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Municipal code
Zoning
Supplemental regulations
Conditional use
requirements
Food-related uses warrant extra scrutiny
to ensure trash-handling areas, delivery
areas and grease traps are properly
designed and installed.
Are there standards for animal-related uses (e.g., dog daycare centers, kennels)?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Municipal code
Zoning
Supplemental regulations
Conditional use
requirements
Outdoor areas at animal-related facili-
ties should be reviewed to ensure that
drainage from washing or rainfall will be
directed into a sanitary drain or vegetated
area well away from storm drains, surface
waters or wetlands.
A 41GREEN INFRASTRUCTURE AUDIT TOOLPOLLUTANT REDUCTION THROUGH SITE PLAN REVIEW
Are there standards for outdoor storage areas?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Municipal code
Zoning
Supplemental regulations
Conditional use
requirements
Outdoor storage and contractors’ yards
can become substantial sources of
nutrients, toxics, metals or sediment in
runoff. Review should ensure vegetated
buffers, grading plans or other measures
are in place.
Are there standards for contractors’ yards?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Municipal code
Zoning
Supplemental regulations
Conditional use
requirements
Outdoor storage and contractors’ yards
can become substantial sources of
nutrients, toxics, metals or sediment in
runoff. Review should ensure vegetated
buffers, grading plans or other measures
are in place.
Are there standards for other potentially polluting uses?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Municipal code
Zoning
Supplemental regulations
Conditional use
requirements
Locally, other uses such as nurseries
and garden centers might benefit from
supplemental review of outdoor areas
and activities.
A42 GREEN INFRASTRUCTURE AUDIT TOOL POST-CONSTRUCTION STORMWATER STANDARDS AND LONG-TERM MAINTENANCE
POST-CONSTRUCTION STORMWATER STANDARDS AND LONG-TERM MAINTENANCE
Having methods in place to inspect and manage stormwater treatment systems during and after construction is important to the long-term performance of green infrastructure.
Does the municipality have a stormwater utility or user fee to provide a dedicated funding source for stormwater management?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Municipal code Many communities have local, fee-based
funding or a formal utility for storm-
water management. Where fees are not
currently charged, these may be adopted
by referendum under some state laws.
Is there construction-phase inspection of stormwater treatment practices to ensure conformance with the site and stormwater management
plan?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Stormwater ordinance
Written policies and
procedures
Stormwater ordinances should explicitly
require inspection of stormwater treat-
ment systems during the construction
phase, which is critical to function and
performance.
A 43GREEN INFRASTRUCTURE AUDIT TOOLPOST-CONSTRUCTION STORMWATER STANDARDS AND LONG-TERM MAINTENANCE
Is there a process for regular post-construction inspection of stormwater treatment practices for both private and publicly maintained facilities?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Stormwater ordinance
Written policies and
procedures
Regular post-construction inspections
can be reported to the municipality, if a
tracking system is in place, or system
owners may keep their inspection reports
on file.
Are maintenance agreements required for stormwater treatment practices and landscaped areas that accept stormwater runoff?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Stormwater ordinance
Municipal maintenance
agreement
Providing a model maintenance agreement
ensures that developers understand the
municipality’s requirements for ongoing
maintenance and reporting.
Have model maintenance agreements been developed or adopted?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Stormwater ordinance
Municipal maintenance
agreement
Plan review and public works staff benefit
from a working knowledge of green
infrastructure maintenance needs, such
as sweeping frequencies for permeable
surfacing or how to identify invasive plants
in bioretention areas.
A44 GREEN INFRASTRUCTURE AUDIT TOOL POST-CONSTRUCTION STORMWATER STANDARDS AND LONG-TERM MAINTENANCE
Have maintenance needs for green infrastructure practices been communicated and understood among staff involved in plan review
or inspection?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Staff knowledge Plan review and public works staff benefit
from a working knowledge of green
infrastructure maintenance needs, such
as sweeping frequencies for permeable
surfacing or how to identify invasive plants
in bioretention areas.
A 45GREEN INFRASTRUCTURE AUDIT TOOLPUBLIC WORKS STANDARDS
PUBLIC WORKS STANDARDS
Public works standards, which may be part of subdivision regulations, adopted as a separate ordinance or adopted administratively by the municipality, control key aspects
of municipal infrastructure and stormwater systems. Public works staff and commissioners should be actively involved in audits and provide input on how different changes
or alternatives would work.
Do drainage systems allow any use of drain restrictors to hold water back on streets for temporary stormwater storage during larger
storm events?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Zoning
Subdivision
Department of public
works standards
In some communities, providing temporary
flood storage on streets can decrease
the need for large (and costly) storage
facilities. In others, however, this is not
practiced.
Is the minimum pavement width for local streets in medium density residential developments less than 22 feet? Can other widths be reduced?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Zoning
Subdivision
Department of public
works standards
Contemporary standards for roadway
widths often are much narrower than what
is required in subdivision or public works
standards. Comparing local standards
against updated guidance can identify
where local standards may be changed.
A46 GREEN INFRASTRUCTURE AUDIT TOOL PUBLIC WORKS STANDARDS
Are private streets allowed? If so, are reduced roadway widths or alternative drainage permitted for private streets?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Zoning
Subdivision
Department of public
works standards
Some communities will allow reduced
street widths or waive curb-and-drain
requirements if streets are designated as
private roads. This can be a strategy for
reducing effective imperviousness.
Is there a maximum driveway width (e.g., 20 feet for residential/24 feet at roadway opening, 26 feet for commercial/30 feet at roadway
opening)?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Zoning
Subdivision
Department of public
works standards
Driveway widths and widths at roadway
openings can be limited to support both
better access management and reduced
imperviousness.
Do codes allow utilities to be placed under the paved section of the right-of-way or tree lawns? Under what circumstances?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Zoning
Subdivision
Department of public
works standard
If utilities can be placed under a paved
surface rather than requiring an additional
grass strip adjacent to the right-of-way,
the total area in paved plus grass strip
surface is reduced.
A 47GREEN INFRASTRUCTURE AUDIT TOOLPUBLIC WORKS STANDARDS
What is the minimum cul-de-sac radius (e.g., <35 feet)? Can it be modified, and by whom, when and why?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Zoning
Fire protection ordinance
Department of public
works standards
Contemporary engineering standards
for culs-de-sac call for a 35 foot radius
(70’ diameter).
Are alternative turnarounds such as “hammerheads” allowed? What is the approval process?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Zoning
Fire protection ordinance
Department of public
works standards
“Hammerheads” and T-style turnarounds
can reduce the total land consumption and
impervious area needed on a site, espe-
cially in subdivisions and commercial sites.
Can grasscrete be used to meet public safety and fire access needs?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Zoning
Fire protection ordinance
Department of public
works standards
Many types of commercially available
permeable surfacing have sufficient struc-
tural strength to support fire trucks and
can be plowed; these can be substituted
for asphalt in areas of a site that must
provide fire truck access to buildings.
A48 GREEN INFRASTRUCTURE AUDIT TOOL PUBLIC WORKS STANDARDS
Can minimum sidewalk or multi-purpose path width in the community be varied by path segment and type (note widths)?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Department of public
works standards
Subdivision
Planned unit development
Varied widths for sidewalks and recreation
paths allow flexibility to reduce impervious
surface where appropriate but ensure
wide paths where greater use is expected.
Are vegetated open channels allowed in lieu of curb and gutter, and for what uses (e.g., residential, commercial)?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Department of public
works standards
Subdivision
Options for swale drainage, or partial
curb-and-drain profiles with inlets for
bioretention can allow for enhanced water
quality and infiltration.
Can traffic calming measures be co-designed as stormwater-control measures?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Department of public
works standards
Streetscape standards
It is helpful to state specifically
that islands and bump-outs that act
as traffic calming measures are
encouraged to be co-designed to
provide stormwater management or
green infrastructure functions.
A 49GREEN INFRASTRUCTURE AUDIT TOOLPUBLIC WORKS STANDARDS
Is a standard or review process defined for removing impervious surface?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Department of public
works standards
In communities that are redeveloping,
it is useful to have a standard for demo-
lition or removal of impervious surface
and replacement with sufficient soil and
vegetation to enable stormwater infiltra-
tion. The Environmental Protection Agency
Great Lakes Region has developed a
useful model standard.
Is the specified width of tree lawn based on street section and neighborhood type? Is it adequate to support trees at maturity (6 feet in most
cases)?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Subdivision
Department of public
works standards
Tree lawns or terraces should be at least
6 feet wide in most cases, with sufficient
soil depth and composition to support
healthy tree growth. A municipal forester
or extension staff can advise on widths,
soils and depths.
A50 GREEN INFRASTRUCTURE AUDIT TOOL PURPOSE STATEMENTS AND COMMUNITY PLANS
PURPOSE STATEMENTS AND COMMUNITY PLANS
Ensuring that comprehensive or master plans specifically call out green infrastructure, water quality and watershed protection in goals and objectives will provide crucial
policy support for updating regulations, securing grant funds for pilot projects and setting a tone for integrating water resource protection into municipal investments and
development review.
Are watershed water quality and green infrastructure implementation stated goals in the master plan?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Master and
comprehensive plan
Example: “It is the goal of the Municipality
to implement policies, investments,
standards and actions, including the use
of green infrastructure, that will protect
and enhance water quality within the
Municipality and its watersheds.”
Does the master plan describe green infrastructure and water quality outside the “drainage” or “infrastructure” chapter?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Master and
comprehensive plan
Many older comprehensive plans do
not discuss stormwater other than as a
utility issue (i.e., drainage, flood control).
Park and recreation, natural resource,
landscaping, design and sustainability
goals all can reference the potential for
multiple benefits from incorporating green
infrastructure techniques in private and
municipal projects.
A 51GREEN INFRASTRUCTURE AUDIT TOOLPURPOSE STATEMENTS AND COMMUNITY PLANS
Do master plan objectives and recommended actions include green infrastructure pilot projects, new standards, design manual or
other measures?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Master and
comprehensive plan
Specific language such as “complete a
permeable paving demonstration project
in a municipal parking lot” or “update the
downtown design guidelines to include
green infrastructure features” helps in
grant applications.
A52 GREEN INFRASTRUCTURE AUDIT TOOL SANITARY AND STORM SEWER DISCONNECTIONS
SANITARY AND STORM SEWER DISCONNECTIONS
Stormwater and other “clean water” sources should not be directly connected to the sanitary sewer system and may be prohibited from connection in combined sewer areas.
Infrastructure inspections help ensure that illegal connections and potential bacteria sources are eliminated. Green infrastructure such as green roofs and cisterns or other
practices that direct clean water discharges to rain gardens or permeable areas can reduce demands on the storm drain system, reduce street flooding and provide a water
supply for landscape features.
Is an inspection process in place that verifies that clean water sources do not enter the sanitary sewer in separate sewer areas?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Operational
Sewer ordinance
Some communities have specific proce-
dures for determining if clean water
sources are connected to sanitary sewers
and for requiring property owners to
disconnect or replumb if found. These
sources usually include air conditioner
condensate, sump pump discharge and
roof downspouts.
Are there restrictions on downspouts being directly connected to the sanitary sewer?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Sewer ordinance
Public works standards
Building code
In combined sewer overflow areas, down-
spout connections may be prohibited by
the sewer ordinance.
A 53GREEN INFRASTRUCTURE AUDIT TOOLSANITARY AND STORM SEWER DISCONNECTIONS
Can rooftop runoff, air conditioning condensate, sump pump discharges or other “clean water” sources be discharged to pervious areas?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Code (plumbing, building
or sewer)
Code language can clarify how these
sources should be treated, for example,
“Clean water sources including but not
limited to…may be discharged to lawns or
pervious areas a minimum of three (3) feet
from any building foundation or property
line and provided no water is discharged
in such a manner as to cause icing on any
improved surface.”
Is temporary storage of rainwater on rooftops permitted?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Code (building,
plumbing, public works
specifications)
Look for any prohibition that would prevent
using drain restrictors or a green roof from
holding back drainage rather than sending
it directly into a downspout.
At any routine point-of-sale, is the condition of lateral sewer pipes inspected?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Operational
Sewer ordinance
Most communities only inspect at time of
initial construction. Point-of-sale inspec-
tions may be done if there is a private
property infiltration or inflow reduction
program. Community education on sewer
laterals also can be valuable.
A54 GREEN INFRASTRUCTURE AUDIT TOOL STORMWATER MANAGEMENT STANDARDS
STORMWATER MANAGEMENT STANDARDS
Technical provisions in the stormwater ordinance are particularly important to review with the municipal engineer or consulting engineer. Involving applicants’ engineers
who are familiar with how provisions are interpreted also can be helpful in understanding where and how the ordinance or standards could be modified to encourage use
of green infrastructure.
What design criteria (such as those from state departments of natural resources, environmental protection or conservation) are adopted or
referenced in stormwater management plan requirements?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Stormwater ordinance Referring to your state’s conservation
practice standards (if applicable) or
other published design criteria can help
designers and plan reviewers gain confi-
dence that green infrastructure measures
are designed correctly.
Have primary types of green infrastructure practices (e.g., bioretention/rain gardens, permeable surfacing, rainwater harvesting, vegetated
swales, green roofs) been defined in the stormwater ordinance or zoning regulations?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Stormwater ordinance Adding definitions of different green infra-
structure practices is especially important
to providing guidance and encouragement
to applicants and effective standards for
its use in the community.
A 55GREEN INFRASTRUCTURE AUDIT TOOLSTORMWATER MANAGEMENT STANDARDS
What design storm is used for sizing stormwater-control measures?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Stormwater ordinance Requirements to size stormwater systems
for very large storms can discourage the
use of green infrastructure or distributed
practices, and may lead to other mainte-
nance issues. A one- or two-year storm
typically is consistent with the use of
green infrastructure practices and with
state standards.
Do sizing requirements vary by soil type?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Stormwater ordinance If designers must assume a “D” soil
regardless of on-site conditions, runoff
volumes will be larger than otherwise
needed, which may discourage the use of
green infrastructure practices. Most state
standards provide for variation in curve
numbers based on soil type.
Are green infrastructure practices counted toward meeting the volume control requirements for a site?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Stormwater ordinance It is very important for the local ordinance
to be clear about how the local engineer
will “credit” the volume managed by
different green infrastructure practices.
Some communities limit the volume credit
for permeable surfacing, which discour-
ages its use. Often, state departments
of natural resources or environmental
protection and university extension staff
can provide guidance on this issue.
A56 GREEN INFRASTRUCTURE AUDIT TOOL STORMWATER MANAGEMENT STANDARDS
Are green infrastructure practices counted toward meeting the water quality requirements for a site?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Stormwater ordinance The local ordinance should specify that
green infrastructure practices are accept-
able to the municipal engineer for meeting
TSS and pollutant reduction goals.
Does the use of permeable materials reduce the stormwater quantity required to be managed? If so, is this a written or informal standard?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Stormwater ordinance To encourage the use of permeable
surfacing, stormwater management plans
must “count” these areas as permeable
(or at least at a lower runoff curve number
than impervious surfaces) and provide
credit for volume reduction as well.
Are there reduced [or modified] stormwater-control requirements for redevelopment and infill sites (e.g., waivers of quantity control
requirements, fee-in-lieu options)?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Stormwater ordinance Providing less stringent volume and
treatment requirements for small or
“infill” projects helps encourage infill
and redevelopment.
A 57GREEN INFRASTRUCTURE AUDIT TOOLSTORMWATER MANAGEMENT STANDARDS
Is there a process for identifying or requiring measures that reduce stormwater runoff when existing developed sites are modified, even if a full
stormwater management plan is not required?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Stormwater ordinance Through zoning or stormwater ordinances,
communities can require applicants to
make “low-hanging fruit” modifications
to sites to improve stormwater manage-
ment when development occurs, even
if a full stormwater management plan is
not required. These include modifying
parking lot landscaping to accept sheet
flow, replacing low-use paved areas with
permeable surfacing, replacing turf-
grass with deeper-rooted vegetation and
adding trees.
Is there a reported preference for wet ponds with fountains as an aesthetic approach?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Staff knowledge Moving community preferences from
encouraging wet ponds with fountains
towards distributed, naturalized storm-
water treatment can take time and
education. A statement in the storm-
water ordinance or comprehensive plan
encouraging consideration of different
landscaping and stormwater strategies
is important.
A58 GREEN INFRASTRUCTURE AUDIT TOOL STORMWATER MANAGEMENT STANDARDS
Are incentives provided (within the utility fee structure or elsewhere in the code) to developers who reduce impervious cover, conserve natural
areas or implement stormwater reduction practices such as green rooftops, rain barrels and rain gardens (e. g., reduced stormwater utility fees,
stormwater credits)?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Stormwater utility ordi-
nance credit policy
Where municipalities have a stormwater
utility or fee, it is very helpful to provide
language that specifically allows credits
for treatment with green infrastructure
practices as well as “ponds.”
A 59GREEN INFRASTRUCTURE AUDIT TOOLSUBDIVISIONS AND NEW “GREENFIELD” DEVELOPMENT
SUBDIVISIONS AND NEW “GREENFIELD” DEVELOPMENT
Amending regulations related to new development can help reduce the footprint, and consequently the spread, of impervious surfaces. Suggestions include reducing minimum
requirements for lot sizes, lot frontage and setbacks and allowing for shared driveways.
Are there provisions that encourage minimizing total impervious surfaces on new development sites (if they are consistent with building
patterns in the zoning district)?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Subdivision
Planned development unit
regulations
Reducing lot widths and minimum sizes
reduces the amount of land area disturbed
for new development, the total length
of roadway and associated impervious
surface required, and the amount of turf-
grass for lawn — all of which reduce the
volume of runoff and pollutant loads asso-
ciated with new development. Guidance
on conservation subdivisions or “smart
growth” can provide useful standards
and examples.
Are flexible dimensional criteria available for developers using planned development units, open space or cluster design options (e.g., setbacks,
lot sizes and shapes, road widths)?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Subdivision
Planned development unit
regulations
Reducing lot widths and minimum sizes
reduces the amount of land area disturbed
for new development, the total length
of roadway and associated impervious
surface required, and the amount of turf-
grass for lawn — all of which reduce the
volume of runoff and pollutant loads asso-
ciated with new development. Guidance
on conservation subdivisions or “smart
growth” can provide useful standards
and examples.
A60 GREEN INFRASTRUCTURE AUDIT TOOL SUBDIVISIONS AND NEW “GREENFIELD” DEVELOPMENT
Are flexible standards (planned development units, open space or cluster options) as-of-right or discretionary? What is the minimum lot size for
an open space subdivision or a planned development unit?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Subdivision
Planned development
unit regulations
Reducing lot widths and minimum sizes
reduces the amount of land area disturbed
for new development, the total length
of roadway and associated impervious
surface required, and the amount of turf-
grass for lawn — all of which reduce the
volume of runoff and pollutant loads asso-
ciated with new development. Guidance
on conservation subdivisions or “smart
growth” can provide useful standards
and examples.
Can lot frontage requirements be waived in a planned development unit or open space subdivision?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Subdivision
Table of dimensional
standards
Planned development
unit regulations
Lot frontage requirements (i.e., length of
a lot that must abut a street) are often
a hold-over from earlier zoning goals.
Reducing lot frontage requirements can
help spur redevelopment along commer-
cial strips and, in subdivisions, reduces
the total length of roadway required.
Provisions can be drafted that ensure
each lot has sufficient legal access to
a public roadway, without requiring
large frontages.
A 61GREEN INFRASTRUCTURE AUDIT TOOLSUBDIVISIONS AND NEW “GREENFIELD” DEVELOPMENT
Are the frontage requirements standard, minimal or above usual practice?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Table of dimensional
standards
Reduced setbacks (frontage, front, side
and rear) can allow for reduced roadway
and driveway length, and smaller areas
of turfgrass.
Are the front yard setbacks standard, minimal or above usual practice for the zoning district?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Table of dimensional
standards
Reduced setbacks (frontage, front, side
and rear) can allow for reduced roadway
and driveway length, and smaller areas
of turfgrass.
Are the side yard setbacks standard, minimal or above usual practice for zoning district?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Table of dimensional
standards
Reduced setbacks (frontage, front, side
and rear) can allow for reduced roadway
and driveway length, and smaller areas
of turfgrass.
A62 GREEN INFRASTRUCTURE AUDIT TOOL SUBDIVISIONS AND NEW “GREENFIELD” DEVELOPMENT
Are the rear yard setbacks standard, minimal or above usual practice for the zoning district?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Table of dimensional
standards
Reduced setbacks (frontage, front, side
and rear) can allow for reduced roadway
and driveway length, and smaller areas
of turfgrass.
Can stormwater-control measures be sited within required yard or setback areas? If so, are there any limitations on siting ponds within yards or
setbacks?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Zoning
General regulations
[definitions of setbacks
or yards]
Staff knowledge
Allowing ponds, bioretention areas or
other surface stormwater controls within
setbacks typically increases the density
that can be achieved on the site.
Are shared driveways allowed/encouraged? For what land uses?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Subdivision
Zoning and site plan
Public works standards
Allowing shared driveways among parcels
or land uses can reduce both curb cuts
and impervious surface area.
A 63GREEN INFRASTRUCTURE AUDIT TOOLZONING
ZONING
Specific aspects of the structure of a zoning code can be modified or clarified to ensure that green infrastructure practices are clearly allowed or encouraged in development
and in municipally sponsored projects.
Is a description or definition of “low impact development” or “green infrastructure” included in the zoning code or stormwater ordinance?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Zoning
Definitions
An inclusive definition of green infra-
structure can be: “Vegetated stormwater
management measures. Swales, bioret-
ention areas, rain gardens, amended soil
areas, pocket or modular wetlands, storm-
water trees, vegetated or green roofs, and
similar practices specifically designed to
provide water quantity and water quality
treatment of stormwater runoff, and to
promote evapotranspiration and infiltration
of stormwater.”
Do purpose statements in zoning specifically include encouraging green infrastructure or naturalized drainage?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Zoning
Establishment [individual
zoning districts]
Example: “It is the purpose of these
standards to promote the use of green
infrastructure or vegetated stormwater
management measures, where suitable,
to manage stormwater runoff volumes
and quality.”
A64 GREEN INFRASTRUCTURE AUDIT TOOL ZONING
Is there a clear process for approving green infrastructure, flood management or environmental restoration projects? Would these projects be
allowed in all zoning districts?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Zoning
Individual zoning districts
[site plan procedures]
The zoning code should note whether land
modifications to implement wetland or
stream restoration, construct stormwater
retrofits or modify landscaping and grading
requires plan commission, elected board
or staff approval and whether approval
goes through site plan, conditional use or
another approval process.
Do allowable uses for parks and other open space areas specifically include stormwater retrofits or green infrastructure projects?
Barrier Tips Code References and Language Notes, Ideas and Strategies Grade
Zoning
Table of uses [individual
zoning districts]
Depending on the community, the list of
permitted or conditional uses may need
to include “stormwater management and
green infrastructure installations” or a
similar use to enable stand-alone projects.
R 1GREEN INFRASTRUCTURE REPORT CARD
Green Infrastructure Audit Tool Report Card
A quick-reference summary to determine whether a code, policy or operation is enabling, conditional, ambiguous, discouraging or conflicting.
ARCHITECTURAL DESIGN STANDARDS
Are rainwater-harvesting and stormwater-control elements
acknowledged in design standards?
Are green infrastructure practices suitable for high-density areas (e.g.,
planter boxes, cisterns) allowed to extend into the right-of-way
or onto sidewalks?
Do design standards allow siting of stormwater-control measures
along façade?
Do standards allow for the waiver of design or architectural provisions
to accommodate stormwater-control measures (planters, cisterns,
green roofs, etc.)?
Are pitched roofs required? If so, is a waiver or provision for green
roofs or rainwater harvesting made?
Are green infrastructure practices suitable for high-density areas
allowed or encouraged in streetscapes (e.g., tree boxes, sidewalk
bioretention areas, curb bump-outs)?
COASTAL COMMUNITIES
Is protection of bluffs and ravines described in the Comprehensive
Plan and ordinance?
Are there review procedures over and above other code provisions for
activities in proximity to bluffs and ravines?
Are there provisions or setbacks from bluffs and ravines for new or
expanded structures?
Are there provisions or setbacks from bluffs and ravines for new
impervious surfaces?
Are there provisions on clearing and grading near bluffs and ravines?
Can foundation drain, roof leaders or sump pump discharges be sited
where discharge will exit on the slope of a bluff or ravine? What is the
review process, if any?
Has the community identified stormwater outfalls flowing directly onto
beaches or into streams that flow directly to beaches?
R2 GREEN INFRASTRUCTURE REPORT CARD
COMMUNITY OUTREACH AND EDUCATION
Is there a local ordinance or policy limiting the application of
pesticides or herbicides on public property?
Has green infrastructure education been provided to staff involved in
plan reviews? This includes staff in public safety, engineering, parks
and recreation, economic development, and planning and zoning.
Has green infrastructure education been provided to planning boards
and elected officials?
Has a rain barrel or rain garden pilot program been done in
your community?
Is a review or procedure in place for rain garden construction and
planting native plants in yards and lawns?
Is a review or procedure in place for downspout disconnection and
rain barrel installation?
Is a review or permit process in place to facilitate the disconnection of
foundation drains?
Who answers inquiries and what is his or her level of knowledge?
CONSTRUCTION AND POST-CONSTRUCTION MANAGEMENT
Does the ordinance require or promote preservation of native
vegetation at development sites?
Does the ordinance require or encourage limiting clearing and
grading at development sites (e.g., construction-site phasing,
clearing limit demarcation requirements, prohibitions on construction
equipment storage)?
Are the limits of disturbance shown on site plans required to be
physically marked on the construction site?
Does the ordinance include construction-phase inspection of limits
of disturbance?
Do site and erosion control plans require identification, site marking
and protection of mature trees?
Are native or hydric soils required to be identified, demarcated and
protected from disturbance and construction activity?
Are management plans required for open space and conservation
areas set aside in development?
If open space or conservation areas are required, does a minimum
percentage have to be managed in a natural condition (e.g.,
maintained as woodland, deep-rooted plantings or native vegetation
instead of turf)?
Are there supplemental provisions for protecting or buffering wetlands
that are above state requirements?
Has the community identified historic stream channels and
waterways? Are any of these features protected from modification or
development?
R 3GREEN INFRASTRUCTURE REPORT CARD
LANDSCAPING
Do preliminary or sketch plans include stormwater measures and
landscape techniques for initial review?
Is a consolidated plan for landscaping, grading/drainage and
stormwater-control measures encouraged or required?
Is the use of deep-rooted or native plants, plants with habitat value, or
edibles allowed or encouraged in the landscaping standards?
Is there a process or standard to waive numerical, spacing and
species requirements for stormwater-control measures in required
landscape areas?
Do visual buffer and screening provisions enable a variation in
plantings or substitution of fencing if co-designed for stormwater?
Do vegetated stormwater management areas such as bioretention
areas, rain gardens, stormwater trees or other plantings count toward
required landscape minimums?
Is berming of setback and landscape areas along right-of-ways
required and/or habitually preferred as a method of visual screening?
Are naturalized landscaping standards and requirements promoted for
use in stormwater treatment practices?
Are there minimum landscaping requirements for parking lots?
Perimeters, islands or both (e.g., percentage of parking landscaped,
number of trees per parking spaces, canopy coverage)?
Is there a minimum size for parking lot landscape islands?
Do parking lot edge landscaping requirements (islands and edges)
specifically allow or encourage use as stormwater-control areas? Is a
standard adopted?
Are flush curbs and/or curb cuts allowed to direct runoff into
vegetated landscaped islands?
Are green walls defined or encouraged? Do they count toward
required landscaping?
Is turfgrass required in new subdivisions or construction? Could deep-
rooted plants be substituted?
Do the standards encourage or require that turfgrass be used only for
active recreation areas?
Are snow storage areas required to be shown on site plans?
Is snow storage in bioretention areas prohibited or discouraged,
unless the area is specifically designed for snow storage (i.e., grass
swales)?
Are street trees required or encouraged along streets (residential,
commercial, other or all)?
Are tree lawns and terraces allowed or encouraged to be designed as
stormwater treatment areas rather than turfgrass and trees only?
Can landscaped islands for stormwater treatment be created within
culs-de-sac or medians?
Are native plantings specifically allowed in front yards or lawn areas?
R4 GREEN INFRASTRUCTURE REPORT CARD
PARKING
Do parking ratios reflect current Urban Land Institute or Institute of
Transportation Engineers recommended ratios of spaces per square
feet of gross floor area?
Are the uses in the parking regulations updated to reflect
contemporary development types (e.g., drive-through pharmacies,
large home improvement stores) and eliminate outdated ones (e.g.,
video rental, photo processing, men’s clothiers)?
Are parking ratios set as maximum or median (rather than minimum)
requirements?
Do dense districts eliminate on-site parking requirements or have
reduced requirements?
Is the parking ratio reduced if shared parking arrangements are
in place or multi-modal transit (e.g., mass transit, bike-n-shower
facilities) is provided nearby? (Note distance to transit.)
Are there incentives to developers to provide parking within
garages rather than surface parking lots (structured parking funded/
incentivized where suitable to zoning district)?
Is the minimum stall width for a standard parking space 9 feet or less?
Is the minimum stall length for a standard parking space 18 feet
or less?
Are flexible space sizes and/or compact parking spaces allowed or
encouraged? What percentage or limits?
Is the use of shared parking arrangements promoted?
Is a shared parking agreement format, calculation and administration
procedure for changes in use in place?
Is the use of off-site parking arrangements promoted?
Is an off-site parking agreement or recording document provided
or adopted?
How many off-street parking spaces per residence are allowed or
required? How many driveway spaces are allowed or required?
Is there a maximum number of cars or area of off-street or driveway
parking per single family residence?
Is there a prohibition on parking on vegetated areas or
required yards?
PERMEABLE MATERIALS
Does the municipality have experience with permeable material,
curbless streets or other green infrastructure measures?
Are standard specifications or performance standards adopted or
referenced for permeable materials?
Must a sealant be used on improved surfaces, and, if so, can that
provision be waived?
Are low-volume street sections allowed or encouraged to
be permeable?
Can parking lanes along streets be constructed with
permeable surfacing?
Is the width or total surface area of driveways limited (e.g., as percent
of lot area)? Can permeable driveways exceed that limitation?
Are driveway aprons allowed or encouraged to be permeable?
R 5GREEN INFRASTRUCTURE REPORT CARD
POLLUTANT REDUCTION THROUGH SITE PLAN REVIEW
Are standards and requirements adopted for trash areas
and dumpsters?
Are trash/dumpster areas required to have four-sided enclosures?
Are trash/dumpster areas required to be covered?
Are trash/dumpster areas reviewed for drainage?
Are there supplemental standards for potentially polluting uses?
Are there standards for gas and auto repair stations?
Are there standards for food-related uses?
Are there standards for animal-related uses (e.g., dog daycare
centers, kennels)?
Are there standards for outdoor storage areas?
Are there standards for contractors’ yards?
Are there standards for other potentially polluting uses?
POST-CONSTRUCTION STORMWATER STANDARDS AND LONG-TERM MAINTENANCE
Does the municipality have a stormwater utility or user fee to provide a
dedicated funding source for stormwater management?
Is there construction-phase inspection of stormwater treatment
practices to ensure conformance with the site and stormwater
management plan?
Is there a process for regular post-construction inspection of
stormwater treatment practices for both private and publicly
maintained facilities?
Are maintenance agreements required for stormwater treatment
practices and landscaped areas that accept stormwater runoff?
Have model maintenance agreements been developed or adopted?
Have maintenance needs for green infrastructure practices been
communicated and understood among staff involved in plan review
or inspection?
R6 GREEN INFRASTRUCTURE REPORT CARD
PUBLIC WORKS STANDARDS
Do drainage systems allow any use of drain restrictors to hold water
back on streets for temporary stormwater storage during larger
storm events?
Is the minimum pavement width for local streets in medium-density
residential developments less than 22 feet? Can other widths
be reduced?
Are private streets allowed? If so, are reduced roadway widths or
alternative drainage permitted for private streets?
Is there a maximum driveway width (e.g., 20 feet for residential/24
feet at roadway opening, 26 feet for commercial/30 feet at roadway
opening)?
Do codes allow utilities to be placed under the paved section of the
right-of-way or tree lawns? Under what circumstances?
What is the minimum cul-de-sac radius (e.g., <35 feet)? Can it be
modified, and by whom, when and why?
Are alternative turnarounds such as “hammerheads” allowed? What is
the approval process?
Can grasscrete be used to meet public safety and fire access needs?
Can minimum sidewalk or multi-purpose path width in the community
be varied by path segment and type (note widths)?
Are vegetated open channels allowed in lieu of curb and gutter, and
for what uses (e.g., residential, commercial)?
Can traffic calming measures be co-designed as stormwater-control
measures?
Is a standard or review process defined for removing
impervious surface?
Is the specified width of tree lawn based on street section and
neighborhood type? Is it adequate to support trees at maturity (6 feet in
most cases)?
PURPOSE STATEMENTS AND COMMUNITY PLANS
Are watershed water quality and green infrastructure implementation
stated goals in the master plan?
Does the master plan describe green infrastructure and water quality
outside the ‘drainage’ or ‘infrastructure’ chapter?
Do master plan objectives and recommended actions include green
infrastructure pilot projects, new standards, design manual or
other measures?
R 7GREEN INFRASTRUCTURE REPORT CARD
SANITARY AND STORM SEWER DISCONNECTIONS
Is an inspection process in place that verifies that clean water sources
do not enter the sanitary sewer in separate sewer areas?
Are there restrictions on downspouts being directly connected to the
sanitary sewer?
Can rooftop runoff, air conditioning condensate, sump pump
discharges or other “clean water” sources be discharged to
pervious areas?
Is temporary storage of rainwater on rooftops permitted?
At any routine point-of-sale, is the condition of lateral sewer
pipes inspected?
STORMWATER MANAGEMENT STANDARDS
What design criteria (such as those from state departments of natural
resources, environmental protection or conservation) are adopted or
referenced in stormwater management plan requirements?
Have primary types of green infrastructure practices (e.g.,
bioretention/rain gardens, permeable surfacing, rainwater harvesting,
vegetated swales, green roofs) been defined in the stormwater
ordinance or zoning regulations?
What design storm is used for sizing stormwater-control measures?
Do sizing requirements vary by soil type?
Are green infrastructure practices counted toward meeting the volume
control requirements for a site?
Are green infrastructure practices counted toward meeting the water
quality requirements for a site?
Does the use of permeable materials reduce the stormwater quantity
required to be managed? If so, is this a written or informal standard?
Are there reduced (or modified) stormwater-control requirements
for redevelopment and infill sites (e.g., waivers of quantity control
requirements, fee-in-lieu options)?
Is there a process for identifying or requiring measures that reduce
stormwater runoff when existing developed sites are modified, even if
a full stormwater management plan is not required?
Is there a reported preference for wet ponds with fountains as an
aesthetic approach?
Are incentives provided (within the utility fee structure or elsewhere
in the code) to developers who reduce impervious cover, conserve
natural areas or implement stormwater reduction practices such
as green rooftops, rain barrels and rain gardens (e. g., reduced
stormwater utility fees, stormwater credits)?
SUBDIVISIONS AND NEW “GREENFIELD” DEVELOPMENT
Are there provisions that encourage minimizing total impervious
surfaces on new development sites (if they are consistent with building
patterns in the zoning district)?
Are flexible dimensional criteria available for developers using
planned development units, open space or cluster design options (e.g.,
setbacks, lot sizes and shapes, road widths)?
Are flexible standards (planned development units, open space or
cluster options) as-of-right or discretionary? What is the minimum lot
size for an open space subdivision or a planned development unit?
Can lot frontage requirements be waived in a planned development
unit or open space subdivision?
Are the frontage requirements standard, minimal or above
usual practice?
Are the front yard setbacks standard, minimal or above usual practice
for the zoning district?
Are the side yard setbacks standard, minimal or above usual practice
for zoning district?
Are the rear yard setbacks standard, minimal or above usual practice
for the zoning district?
Can stormwater-control measures be sited within required yard or
setback areas? If so, are there any limitations on siting ponds within
yards or setbacks?
Are shared driveways allowed/encouraged? For what land uses?
ZONING
Is a description or definition of “low impact development” or “green
infrastructure” included in the zoning code or stormwater ordinance?
Do purpose statements in zoning specifically include encouraging
green infrastructure or naturalized drainage?
Is there a clear process for approving green infrastructure, flood
management or environmental restoration projects? Would these
projects be allowed in all zoning districts?
Do allowable uses for parks and other open space areas specifically
include stormwater retrofits or green infrastructure projects?
seagrant.wisc.edu/greeninfrastructure
seagrant.wisc.edu/greeninfrastructure