Difference between revisions of "LID opportunities on public land"

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==Small- and large-scale projects==
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The scale of your LID project will largely determine how to proceed. While you can usually complete small-scale LID projects with in-house expertise and resources, large-scale projects require external support from consultants and contractors.
 +
 +
===Small-scale projects===
 +
 +
[[File:Example4.jpg|thumb|A [[no-mow]] zone is a landscape alternative that does not require construction activities. (Source: Aquafor Beech)]]
 +
 +
[[File:Fletchers Creek Senior School - planting - 2013.jpg|thumb|right|A student helps with planting at Fletchers Creek Senior School. Small-scale LID projects are a great way to engage with the next generation of environmental stewards. Source: CVC]]
 +
 +
Starting with small-scale projects is a good strategy to increase public interest in LID practices, gauge municipal support, and gain retrofit experience. Small-scale projects include retrofitting your site with [[Landscape alternatives|landscape alternatives]], [[Rain barrels|rain barrels]], enhancements of existing swales, or using [[Pollution prevention|pollution prevention]] strategies and practices.
 +
Small-scale projects require fewer resources and a smaller project budget:
 +
*They do not require integration into capital works projects
 +
*Engineering consultants are not required
 +
*Contractors may not be not required
 +
*External approvals are not required
 +
*Consultation with the public is limited
 +
 +
Due to less financial commitment, it can be easier to build colleague support and to gain supervisor approval for small-scale projects. However, small-scale projects like landscape alternatives and pollution prevention may not be easily identified as LID practices by the public. Your project team should consider establishing educational signage to inform the public.
 +
 +
Pollution prevention (P2) projects are great small-scale projects for municipal facilities, such as schools and public works yards. Many P2 techniques and strategies do not require construction, consultants or contractors. In fact, simply adding signage to a site is a simple and easy to implement pollution prevention at municipal facilities.
 +
 +
A successful small-scale LID retrofit project is a good indication that you are ready to take on a more intensive retrofit project. You now know the resources that are available and understand the internal municipal processes required to move a LID project from planning to finished product.
 +
 +
===Large-scale projects===
 +
 +
[[File:Example5.jpg|thumb|When installing new parks equipment, consider whether the LID practices can be integrated into the design. Here a bioswale has been built into the landscape between a playground and sidewalk. (Source: CVC)]]
 +
 +
Large-scale projects require significantly more effort, budget and staff than small-scale projects. Large-scale LID practices include:
 +
* [[Bioretention]]
 +
* [[Enhanced grass swales]]
 +
* [[Bioswales]]
 +
* Perforated pipe systems
 +
* [[Permeable pavements]]
 +
* [[Soakaways, Infiltration Trenches and Infiltration Chambers Guide|Soakaways]]
 +
* [[Infiltration chambers]]
 +
* [[Rainwater harvesting]]
 +
* Prefabricated modules
 +
* [[Green roofs]]
 +
 +
Consider a large-scale project if your municipality, school or place of worship would like to be a leader in sustainability. Large-scale projects are often highly visible and attract more public attention. Large-scale projects may also be the only solution to site-specific challenges. For example, if the parking lot on your site does not have existing stormwater controls, small-scale projects are not likely to fully achieve compliance with water quality and quantity objectives. Consider using an infiltration chamber or bioswale project to meet those objectives.
 +
Before starting a large-scale retrofit project, consider the following distinctions that set these retrofits apart from small-scale projects.
 +
 +
====Integration with capital works programs====
 +
 +
Most large-scale LID retrofits must function with existing site infrastructure, such as storm sewers, catch basins, and pavement systems. The construction of large-scale LID practices often requires these systems to be removed, exposed, or replaced. The best time for this type of project to occur is when an infrastructure replacement or rehabilitation project is already planned.
 +
 +
When LID retrofits are worked into other construction projects, such as parking lot repaving, or grading or drainage improvements, there can be substantial cost savings. Whether big or small, every municipality, school and place of worship spends relatively large sums of money and substantial time planning for major capital projects. This includes redevelopment of public buildings and spaces. Many communities which have undertaken retrofits recognize that even if a relatively small portion of the project funds goes towards LID retrofits, they can retrofit large impervious surfaces and avoid new stormwater management infrastructure projects.
 +
 +
Municipal facility rehabilitation is typically forecast well in advance of the project. Parking lot paving is typically worked into municipal budgets based on expected life cycle and observed wear. As such, funds may be set aside prior to the project planning phases. Long-term forecast budgets may also be available for site revitalization or expansion. These budget forecasts provide opportunities to compare the capital and life-cycle costs and benefits of conventional construction projects against LID retrofits.
 +
 +
====Regulatory compliance====
 +
 +
The objectives, technologies and standard practices associated with stormwater management are constantly evolving. It is unlikely that the stormwater management practices on your site meet modern industry standards. When you are making changes to your site, it is important to stay ahead of regulation. Your school, park, place of worship or municipal facility may not be required to improve on-site stormwater management infrastructure, but those retrofits can be beneficial and save money and time over the long term. Consider both current and future water regulations which may affect your property. Consulting with your municipality will help you determine if LID retrofits can reduce taxes or prevent costly upgrades required at a later date.
 +
 +
====Involvement of consultants and contractors====
 +
 +
Consultants are required for large-scale retrofit projects, specifically for the final screening of options, pre-design, detailed design, tender and contract documents, construction supervision and administration, and assumption and verification. Site contractors are also required for large-scale LID retrofits.
 +
 +
Ideally, contractors should be pre-qualified based on previous experience with similar LID projects. Remember, the contractor with the lowest bid does not necessarily deliver the best product.
 +
 +
====Intensive public consultation====
 +
 +
Stakeholders must be closely involved in the retrofit process for large-scale LID projects. These projects have longer construction windows, may have significant impacts on long term public use patterns of the site and will have significantly higher costs. Gaining public insight before LID implementation can help address public concerns and information gaps, as well as identify public supporters and champions. Public consultation can help designers tailor the project to address community concerns, values and use-patterns.
 +
 +
====External approvals====
 +
 +
Large-scale retrofits may require a variety of approvals at the municipal, watershed, provincial, and/or federal level. Since LID is still relatively new, you may encounter policies or bylaws that present barriers to LID retrofit projects. Alternatively, the municipality may have to amend or enforce some policies and bylaws to facilitate the implementation of LID projects on your site.
  
 
==Parks==
 
==Parks==
 +
 
[[File:Example.jpg|thumb|The bioretention area installed at O’Connor Park in Mississauga is part of a stormwater management system that treats parking lot runoff prior to discharging to a local wetland. (Source: CVC)]]
 
[[File:Example.jpg|thumb|The bioretention area installed at O’Connor Park in Mississauga is part of a stormwater management system that treats parking lot runoff prior to discharging to a local wetland. (Source: CVC)]]
 
[[File:Example1.jpg|thumb|Urban parkettes may look small, but they have the potential to treat a large surface area of road. Typical ratios of impervious drainage area to a bioretention range from 5:1 to 15:1. (Source: CVC)]]
 
[[File:Example1.jpg|thumb|Urban parkettes may look small, but they have the potential to treat a large surface area of road. Typical ratios of impervious drainage area to a bioretention range from 5:1 to 15:1. (Source: CVC)]]
 
[[File:Example3.jpg|thumb|The road surface (left) contributes significantly more stormwater pollutants than the parkland area (right). To achieve maximum watershed benefit a designer could consider accepting runoff from this external area. (Source: CVC)]]
 
[[File:Example3.jpg|thumb|The road surface (left) contributes significantly more stormwater pollutants than the parkland area (right). To achieve maximum watershed benefit a designer could consider accepting runoff from this external area. (Source: CVC)]]
[[File:Example6.jpg|thumb|Source areas within a typical park]]
+
 
  
 
Parks range from simple parcels of municipal property to complex outdoor recreational facilities that include parking, sidewalks, trails, sports fields, field houses, operations facilities and washrooms. Each distinct area of your site can be a source for runoff (referred to as a ‘source area’). Target these areas when introducing LID in your park.
 
Parks range from simple parcels of municipal property to complex outdoor recreational facilities that include parking, sidewalks, trails, sports fields, field houses, operations facilities and washrooms. Each distinct area of your site can be a source for runoff (referred to as a ‘source area’). Target these areas when introducing LID in your park.
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located adjacent to pervious areas such as lawns, gardens or naturalized areas. This makes parks an ideal location for a LID retrofit. Where grading allows, you can construct [[bioswales]] and [[bioretention]] areas in these green areas to pre-treat water prior to infiltration.
 
located adjacent to pervious areas such as lawns, gardens or naturalized areas. This makes parks an ideal location for a LID retrofit. Where grading allows, you can construct [[bioswales]] and [[bioretention]] areas in these green areas to pre-treat water prior to infiltration.
  
You can also design parking surfaces and internal roadways as infiltration systems using permeable pavement. This retrofit strategy can be combined with other LID practices. Pathways paved with [[permeable paving]] are another LID option for your park. They reduce runoff volumes and encourage on-site infiltration. [[Exfiltration trenches]] are a viable option on many parks sites as well, as they provide an alternative to conventional conveyance systems (such as storm sewers). They encourage infiltration from hard surfaces and can be used to convey water to other LID features.
+
You can also design parking surfaces and internal roadways as infiltration systems using permeable pavement. This retrofit strategy can be combined with other LID practices. Pathways paved with [[permeable pavements]] are another LID option for your park. They reduce runoff volumes and encourage on-site infiltration. [[Exfiltration trenches]] are a viable option on many parks sites as well, as they provide an alternative to conventional conveyance systems (such as storm sewers). They encourage infiltration from hard surfaces and can be used to convey water to other LID features.
+
 
 
===Accepting drainage from off-site areas===   
 
===Accepting drainage from off-site areas===   
  
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===Inter-municipal transfer of funds===
 
===Inter-municipal transfer of funds===
 +
 
Integrating LID practices into the municipal stormwater management framework may require a change in how municipal funds are managed. Traditional stormwater management maintenance resources and funds may have to be transferred to a more landscape-based stormwater management maintenance program. Instead of infrequent but expensive stormwater management pond sediment removal operations, time and resources would be spent on more frequent but inexpensive maintenance projects, including pruning and weeding bioretention practices or sweeping permeable pavement.
 
Integrating LID practices into the municipal stormwater management framework may require a change in how municipal funds are managed. Traditional stormwater management maintenance resources and funds may have to be transferred to a more landscape-based stormwater management maintenance program. Instead of infrequent but expensive stormwater management pond sediment removal operations, time and resources would be spent on more frequent but inexpensive maintenance projects, including pruning and weeding bioretention practices or sweeping permeable pavement.
 
Municipalities generally have the required staff and infrastructure within departments (e.g. arborists and horticulturalists in parks departments) to manage the maintenance of LID measures. However, funding this maintenance may require a transfer of funding and additional training.  
 
Municipalities generally have the required staff and infrastructure within departments (e.g. arborists and horticulturalists in parks departments) to manage the maintenance of LID measures. However, funding this maintenance may require a transfer of funding and additional training.  
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===Source Areas===   
 
===Source Areas===   
 
The best LID option for your site will depend what types of source areas are present. Source areas may include:
 
The best LID option for your site will depend what types of source areas are present. Source areas may include:
 +
[[File:Example6.jpg|thumb|Source areas within a typical park]]
 
* Active use areas
 
* Active use areas
 
* Passive use areas
 
* Passive use areas
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* Internal driveways
 
* Internal driveways
 
* Parking lots
 
* Parking lots
On park sites, pollution prevention is often associated with changes to operations and maintenance practices and has not been included in the table below.
+
On park sites, [[Pollution prevention|pollution prevention]] is often associated with changes to operations and maintenance practices and has not been included in the table below.
 
Options and implementation strategies for a few of these source areas will give you some ideas for your park site.
 
Options and implementation strategies for a few of these source areas will give you some ideas for your park site.
 
{| class="wikitable sortable"
 
{| class="wikitable sortable"
Line 41: Line 113:
 
|-
 
|-
 
!Source area
 
!Source area
![[Permeable paving]]
+
![[Permeable pavements]]
 
![[Bioretention]]
 
![[Bioretention]]
 
![[Enhanced grass swales]]
 
![[Enhanced grass swales]]
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|}
 
|}
  
===Making it happen: Approaches to getting LID into parks===
 
The scale of your LID project will largely determine how to proceed. While you can usually complete small-scale LID projects with in-house expertise and resources, large-scale projects require external support from consultants and contractors.
 
 
====Small-scale projects====
 
[[File:Example4.jpg|thumb|A [[no-mow]] zone is a landscape alternative that does not require construction activities. (Source: Aquafor Beech)]]
 
 
Starting with small-scale projects is a good strategy to increase public interest in LID practices, gauge municipal support and gain experience. Small-scale projects include retrofitting your park with landscape alternatives, [[rain barrels]], or by using pollution prevention strategies and practices.
 
 
Small-scale projects require fewer resources and a smaller project budget:
 
* They do not require integration into capital works projects
 
* Engineering consultants are not required
 
* Contractors may not be not required
 
* External approvals are not required
 
* Consultation with the public is limited
 
 
Due to less financial commitment, it can be easier to build colleague support and to gain supervisor approval for small-scale projects. However, small-scale projects like landscape alternatives and pollution prevention may not be easily identified as LID practices by the public. Your project team should consider establishing educational signage to inform the public.
 
 
====Large-scale projects====
 
 
[[File:Example5.jpg|thumb|When installing new parks equipment, consider whether the LID practices can be integrated into the design. Here a bioswale has been built into the landscape between a playground and sidewalk. (Source: CVC)]]
 
[[File:Example5.jpg|thumb|When installing new parks equipment, consider whether the LID practices can be integrated into the design. Here a bioswale has been built into the landscape between a playground and sidewalk. (Source: CVC)]]
 
Large-scale projects require significantly more effort, budget, and staff than small-scale projects. Large-scale LID practices include:
 
* Bioretention
 
* Enhanced grass swales
 
* Bioswales
 
* Perforated pipe systems
 
* Permeable pavement
 
* Soakaways
 
* Infiltration chambers
 
* [[Rainwater harvesting]]
 
* Prefabricated modules
 
 
Consider a large-scale project if your municipality or department would like to be a leader in sustainability. Large scale projects are often highly visible and attract more public attention. Large-scale projects may also be the only solution to site-specific challenges. For example, if the parking lot on your site does not have existing stormwater controls, small-scale projects are not likely to fully achieve compliance with water quality and quantity objectives. Consider using an infiltration chamber or bioswale project to meet those objectives.
 
 
Before starting a large-scale retrofit project, consider the following distinctions that set these retrofits apart from small-scale projects.
 
====Integration with capital works programs====
 
Most large-scale LID retrofits must function with existing site infrastructure, such as storm sewers, catch basins and pavement systems. Constructing large-scale
 
LID practices often requires these systems to be removed, exposed or replaced. Planned infrastructure replacement or rehabilitation projects provide opportunities for implementing LID practices. For example, if a planned project requires removing existing pavement, infiltration chambers, permeable pavement or bioretention can be incorporated. Budget and resources already set aside for infrastructure projects can be set aside for a retrofit project including replacement existing infrastructure.
 
 
====Involvement of consultants and contractors====
 
Consultants are required for large-scale retrofit projects, specifically for the final screening of options, pre-design, detailed design, tender and contract documents, construction supervision and administration, and assumption and verification. Site contractors are also required for large-scale LID retrofits.
 
 
Ideally, contractors should be pre-qualified based on previous experience with similar LID projects.
 
 
====More intensive public consultation====
 
Stakeholders must be closely involved in the retrofit process for large-scale LID projects. These projects have longer construction windows, may have significant impacts on long term public use patterns of the park, and will have significantly higher costs. Gaining public insight in advance of LID implementation can
 
help address public concerns and information gaps, as well as identify public supporters and champions. Public consultation can help designers tailor the project to address community concerns and values.
 
 
====External approvals====
 
Large-scale park retrofits may require a variety of approvals at the municipal, watershed, provincial and/or federal level. Since LID is still relatively new, you may encounter policies or bylaws that present barriers to LID retrofit projects. Alternatively, the municipality may have to enforce some policies and bylaws to facilitate the implementation of LID projects within parks.
 
  
 
[[Category:Planning]]
 
[[Category:Planning]]
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==Schools==
 
==Schools==
 +
 
[[File:Elm Drive Bioretention.JPG|thumb|right|The Peel District School Board's Adult Education Centre South school partnered with the City of Mississauga to manage runoff from the adjacent street, Elm Drive, on their property. This partnership benefits the City by giving it space to provide an enhanced level of stormwater treatment, and benefited the school through the construction of new parking lay-bys for students. The site is maintained by the City of Mississauga. Source: CVC]]
 
[[File:Elm Drive Bioretention.JPG|thumb|right|The Peel District School Board's Adult Education Centre South school partnered with the City of Mississauga to manage runoff from the adjacent street, Elm Drive, on their property. This partnership benefits the City by giving it space to provide an enhanced level of stormwater treatment, and benefited the school through the construction of new parking lay-bys for students. The site is maintained by the City of Mississauga. Source: CVC]]
  
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(referred to as a ‘source area’). These areas should be
 
(referred to as a ‘source area’). These areas should be
 
targeted when introducing LID at your school.
 
targeted when introducing LID at your school.
 +
 
===Targeting hard surfaces===
 
===Targeting hard surfaces===
 +
 
Parking areas represent the most significant source of
 
Parking areas represent the most significant source of
 
pollutant loading from school sites and contribute significantly
 
pollutant loading from school sites and contribute significantly
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integrated into the design. These practices will also function
 
integrated into the design. These practices will also function
 
to improve pedestrian safety and calm traffic.
 
to improve pedestrian safety and calm traffic.
 +
 
Other types of infiltrating practices like infiltration chambers
 
Other types of infiltrating practices like infiltration chambers
 
are gaining acceptance for their easy integration with parking
 
are gaining acceptance for their easy integration with parking
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implement bioswales or bioretention areas. Perforated pipe
 
implement bioswales or bioretention areas. Perforated pipe
 
systems may also work in areas adjacent to parking lots.
 
systems may also work in areas adjacent to parking lots.
 +
 
===Roof options===
 
===Roof options===
 +
 
Schools typically have large flat roofs that produce a significant
 
Schools typically have large flat roofs that produce a significant
 
amount of runoff that is drained internally via rain leaders.
 
amount of runoff that is drained internally via rain leaders.
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providing insulation during the winter and evaporative cooling
 
providing insulation during the winter and evaporative cooling
 
during the summer.
 
during the summer.
 +
 
===Pollution prevention (P2)===
 
===Pollution prevention (P2)===
On school sites, P2 strategies and practices, such as modifying
+
 
 +
On school sites, [[Pollution prevention|P2 strategies and practices]], such as modifying
 
de-icing programs and isolating drainage from waste storage
 
de-icing programs and isolating drainage from waste storage
 
areas, can be applied to operations and maintenance
 
areas, can be applied to operations and maintenance
 
activities. Discuss these changes with your school board and
 
activities. Discuss these changes with your school board and
 
operations staff.
 
operations staff.
 +
 
===School board partnerships with municipalities===
 
===School board partnerships with municipalities===
 +
 
LID practices located on school grounds can also be used to
 
LID practices located on school grounds can also be used to
 
treat stormwater from external properties. These partnership
 
treat stormwater from external properties. These partnership
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Accepting and treating runoff on your existing property can
 
Accepting and treating runoff on your existing property can
 
make funds available through:
 
make funds available through:
Contributions to capital projects like parking lot
+
* Contributions to capital projects like parking lot rehabilitations which include rain gardens, permeable pavements, or subsurface infiltration facilities
rehabilitations which include rain gardens, permeable
+
* Ongoing revenues from long-term land leases to accommodate surface or subsurface LID retrofits
pavements, or subsurface infiltration facilities
+
* Funds for maintenance of on-site LIDs
Ongoing revenues from long-term land leases to
 
accommodate surface or subsurface LID retrofits
 
Funds for maintenance of on-site LIDs
 
  
===Regulatory Compliance===
 
The objectives, technologies, and standard practices
 
associated with stormwater management are constantly
 
evolving. It is unlikely that the stormwater management
 
practices on your site meet modern industry standards.
 
When you are making changes to your site, it is important to
 
stay ahead of the regulations. Your school may not be required
 
to improve on-site stormwater management infrastructure,
 
but those retrofits can be beneficial and save money and time
 
over the long term. Consider both current and future water
 
regulations which may affect your property. Consulting with
 
your municipality will help you determine if LID retrofits can
 
reduce taxes or prevent costly upgrades required at a later
 
date.
 
 
The table below identifies the LID practices that are common,
 
The table below identifies the LID practices that are common,
 
possible and unlikely options for the source areas that you
 
possible and unlikely options for the source areas that you
 
are likely to find on your school site. These source areas are:
 
are likely to find on your school site. These source areas are:
• Active use area
+
[[File:Landforms of a school.JPG|thumb|Source areas within a typical school site.]]
• Passive use area
+
* Active use area
• Pedestrian walkway
+
* Passive use area
• Internal driveway
+
* Pedestrian walkway
• Parking lot
+
* Internal driveway
An aerial photo of a school property with each of these source
+
* Parking lot
areas accompanies Table 5.3.1. Options and implementation
 
strategies for a few of these source areas will give you some
 
ideas for your site.
 
This guide provides two tiers of LID retrofit projects The scale
 
of your LID retrofit project will largely determine how you will
 
proceed with the retrofit process. You can usually complete
 
small-scale LID projects with in-school expertise and
 
resources. Large-scale projects will require external support
 
from consultants and contractors.
 
It is often difficult to ask students or teachers
 
to maintain LID practices during the summer
 
break. Include summer operations staff time in
 
your budget during the planning process.
 
===Small-scale projects===
 
[[File:Fletchers Creek Senior School - planting - 2013.jpg|thumb|right|A student helps with planting at Fletchers Creek Senior School. Small-scale LID projects are a great way to engage with young children. Source: CVC]]
 
Starting with small-scale projects is a good strategy to
 
increase interest within your school, determine what support
 
is available from stakeholder groups (parent council, school
 
board, administration and operations) and gain retrofit
 
experience. Small-scale projects include retrofitting your
 
school property with landscape alternatives or rain barrels, or
 
using pollution prevention strategies and practices.
 
Small-scale projects require fewer resources and require a
 
smaller project budget because:
 
• They do not require integration into long-term
 
infrastructure replacement and rehabilitation plans
 
• Engineering consultants are not required
 
• Contractors may not be required
 
• External approvals are not required
 
• Consultation with the public is limited
 
Due to the smaller financial commitment, it can be easier
 
to build colleague and school board support for small-scale
 
projects.
 
A successful small-scale LID retrofit project on your school
 
property can be a good indication that you are ready to take on
 
a more intensive retrofit project. You now know the resources
 
that are available and understand the internal municipal
 
processes required to move a LID project from planning to
 
finished product.
 
 
 
===Large-scale projects===
 
Large-scale projects require significantly more effort, budget,
 
and staff than small-scale projects. Large-scale LID retrofits
 
include:
 
 
 
* Bioretention
 
* Enhanced grass swales
 
* Bioswales
 
* Perforated pipe systems
 
* Permeable pavement
 
* Soakaways
 
* Infiltration chambers
 
* Rainwater harvesting (excluding rain barrels)
 
* Prefabricated modules
 
* Green roofs
 
  
Consider a large-scale project if your school board is striving
 
to be a leader in sustainability. Large-scale projects are often
 
highly visible and attract more public attention. They may also
 
be the only solution to site-specific challenges. For example, if
 
the parking lot of your site does not have existing stormwater controls, small-scale projects are unlikely to fully achieve
 
compliance with water quality and water quantity objectives.
 
Instead, use a large-scale project like an infiltration chamber
 
or bioswale.
 
Before starting a large-scale retrofit project, consider the
 
following distinctions that set these retrofits apart from small-scale
 
projects.
 
  
[[File:Landforms of a school.JPG|centre|overhead view of a typical school, with LID options identified]]
+
See the landforms of a school picture on the right for ideas on how to target these areas. The table below gives a more detailed breakdown of LID options for different source areas.
 
 
===Integration with long-term infrastructure replacement and rehabilitation plans===
 
Most large-scale LID retrofits must function with existing
 
site infrastructure, such as storm sewers, catch basins,
 
and pavement systems. The construction of large-scale
 
LID practices often requires these systems to be removed,
 
exposed, or replaced. The best time for this type of project to
 
occur is when an infrastructure replacement or rehabilitation
 
project is already planned.
 
Like other large public sites, schools typically have maintenance
 
programs that take into consideration the expected life cycle
 
of critical site components, including parking lots and roofs.
 
To save construction costs, incorporate LID retrofits into
 
these projects and share construction material, construction
 
equipment, staff resources, and time.
 
For example, installing bioretention, infiltration chambers,
 
or permeable pavement in a parking lot will require the
 
existing pavement to be removed. Budget and resources that
 
have been set aside for a parking lot replacement could be
 
transferred to a retrofit project.
 
 
 
===Involvement of consultants and contractors===
 
Consultants are required for large-scale retrofit projects,
 
specifically for the final screening of options, pre-design,
 
detailed design, tender and contract documents, construction
 
supervision and administration, and assumption and
 
verification. The consultant selection process is described in
 
Chapter 7.
 
Site contractors are also required for large-scale LID retrofits.
 
Contractors should be pre-qualified based on previous
 
experience with similar LID projects.
 
Remember, the contractor with the lowest bid
 
does not necessarily deliver the best product.
 
Refer to Chapter 7 for tips on how to select the
 
right contractor for your project.
 
===More intensive public consultation===
 
Stakeholders must be closely involved in the retrofit process
 
for large-scale LID projects. These projects have longer
 
construction windows, larger costs, and will more significantly
 
affect the use patterns of the property. Large-scale projects
 
are also more complex systems that require continued
 
inspections, operations, and maintenance to achieve
 
continued success. All stakeholder groups must be aware of
 
the long-term project needs before implementation.
 
===External approvals===
 
Large-scale retrofits may require a variety of approvals at the
 
municipal, watershed, provincial, and/or federal level.
 
Since LID is still relatively new, you may encounter policies or
 
bylaws that present barriers to LID retrofit projects. Conduct a
 
review of relevant municipal and school board policies prior to
 
implementing a large-scale retrofit. School board policies may
 
require amendments to move forward.
 
===Next Steps===
 
After reading this section you should know how to select the
 
right LID practice for your site. You should also be familiar
 
with the details you need to consider before undertaking an
 
LID retrofit.
 
For further guidance on implementing and constructing LID
 
practices, '''please refer to Chapters 7-9.''' These chapters
 
provides the next steps for you to implement your LID project,
 
including building the project team, creating a design,
 
getting approvals, construction, certification and guidance on
 
operations and maintenance of LID practices.
 
  
 
{| class="wikitable sortable" style="text-align: center;"
 
{| class="wikitable sortable" style="text-align: center;"
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(** = Common, * = Possible, o = Unusual)
 
(** = Common, * = Possible, o = Unusual)
 
! Source area  
 
! Source area  
! [[Permeable pavement]]  
+
! [[Permeable pavements]]  
 
! [[Bioretention]]  
 
! [[Bioretention]]  
 
! [[Enhanced grass swales]] / [[Bioswales|bioswales]]  
 
! [[Enhanced grass swales]] / [[Bioswales|bioswales]]  
 
! [[Green roofs]]  
 
! [[Green roofs]]  
![[Soakaways, Infiltration Trenches and Infiltration Chambers Guide| Soakaways]] and [[Infiltration trenches|infiltration trenches]]  
+
! Soakaways and [[Infiltration trenches|infiltration trenches]]  
 
! [[Exfiltration trenches|Perforated pipe systems]]  
 
! [[Exfiltration trenches|Perforated pipe systems]]  
 
! [[Rainwater harvesting]]  
 
! [[Rainwater harvesting]]  
Line 373: Line 261:
  
 
==Places of worship==
 
==Places of worship==
 +
 +
Each distinct area of a place of worship can be a source for runoff
 +
(referred to as a ‘source area’). One or more of these areas
 +
should be targeted when introducing LID at your place of
 +
worship.
 +
===Targeting hard surfaces===
 +
Hard surfaces such as parking lots are a great opportunity to
 +
implement LID. Parking lots are the main source of runoff and
 +
represent the most significant source of stormwater pollutants
 +
coming from your site.
 +
Parking lots at places of worship are typically busy only on
 +
select days of the week when groups gather for prayer or
 +
other community activities. Due to this intermittent schedule,
 +
parking lots at these facilities are often rented for other
 +
purposes during times of low usage. On sites where peak
 +
demand does not approach the total capacity of the lot,
 +
consider reducing the parking surface.
 +
Retrofit options for these large parking lot areas include
 +
permeable pavement, bioswales and bioretention areas.
 +
A benefit of permeable pavement systems is that they often
 +
have a longer lifespan than conventional infrastructure.
 +
The freeze-thaw cycle of the Ontario climate is tough on
 +
pavement. Frost heaving and slumping can cause cracks and
 +
potholes because of the expansion and contraction of water.
 +
The expected lifespan for conventional asphalt pavement
 +
in a northern climate, such as Ontario, is approximately 15 to
 +
20 years. A well-maintained porous asphalt system can last for
 +
over 30 years, and permeable interlocking concrete pavers
 +
can have a design life of 20 to 25 years or greater.
 +
 +
Prefabricated modular infiltration chambers are gaining
 +
acceptance because they are easy to integrate with parking
 +
lot functions. These subsurface systems are typically installed
 +
over a coarse granular reservoir to provide water storage and
 +
allow infiltration into native soils. Infiltration chambers under
 +
conventional asphalt systems work well on sites where parking
 +
demand does not allow space for a stormwater feature.
 +
 +
Using LID techniques to manage stormwater can also
 +
eliminate or reduce the need for an on-site storm sewer
 +
system. By eliminating piping, failure points in the pavement,
 +
such as areas around catch basins and manholes, can be
 +
eliminated. A design that does not use storm sewers also
 +
negates the need to replace on-site piping, thereby saving
 +
long-term infrastructure replacement costs.
 +
 +
===Landscaped areas===
 +
 +
Landscaped or lawn areas adjacent to the parking lot or
 +
building present opportunities for implementation of LID
 +
practices such as bioswales and bioretention areas. These
 +
areas typically accept runoff from nearby hard surfaces and
 +
provide water quality and water balance benefits.
 +
 +
===Roof options===
 +
 +
Rainwater harvesting systems can be simple or complex
 +
depending on the architecture and roof drainage patterns of
 +
your building. Many places of worship have peaked roofs with
 +
piping to convey water from the rooftop. If your site is set up
 +
this way, it can be easy to integrate harvesting systems into
 +
the landscape surrounding your building.
 +
 +
Roof runoff can also be directed to soakaways located on
 +
passive use areas around your building. Due to the relatively
 +
good quality of this runoff, pre-treatment devices are not
 +
required.
 +
 +
===Source Areas===
 +
The LID option that best fits your site will depend what types
 +
of source areas are present. Types of source areas include:
 +
[[File:Landforms of a place of worship.JPG|thumb|Source areas within a typical place of worship]]
 +
* Active use area
 +
* Passive use area
 +
* Pedestrian walkway
 +
* Internal driveway
 +
* Parking lot
 +
 +
At places of worship, pollution prevention is often associated with
 +
changes to operations and maintenance practices and has
 +
not been included in the table below.
 +
 +
{| class="wikitable sortable" style="text-align: center;"
 +
|+ LID opportunities at Places of Worship <br>
 +
(** = Common, * = Possible, o = Unusual)
 +
! Source area
 +
! [[Permeable pavements]]
 +
! [[Bioretention]]
 +
! [[Enhanced grass swales]] / [[Bioswales|bioswales]]
 +
! [[Green roofs]]
 +
! Soakaways and [[Infiltration chambers|infiltration chambers]]
 +
! [[Exfiltration trenches|Perforated pipe systems]]
 +
! [[Rainwater harvesting]]
 +
! [[Landscape alternatives]]
 +
! Prefabricated modules
 +
! [[Pollution prevention]]
 +
|-
 +
|style="text-align: left;" |Active use area || ** || ** || ** || o || ** || * || o || * || o || o
 +
|-
 +
|style="text-align: left;" |Passive use area || o || ** || * || o || ** || ** || o || ** || ** || o
 +
|-
 +
|style="text-align: left;" |Pedestrian walkway || ** || ** || ** || o || ** || * || o || * || o || o
 +
|-
 +
|style="text-align: left;" |Internal driveway || ** || ** || ** || o || ** || ** || o || o || * || *
 +
|-
 +
|style="text-align: left;" |Parking lot || ** || ** || ** || o || ** || ** || o || o || ** || *
 +
|-
 +
|style="text-align: left;" |Building || * || * || * || ** || ** || * || ** || o || o || *
 +
|}
 +
 +
[[Category: Planning]]

Latest revision as of 18:36, 6 August 2020

Small- and large-scale projects[edit]

The scale of your LID project will largely determine how to proceed. While you can usually complete small-scale LID projects with in-house expertise and resources, large-scale projects require external support from consultants and contractors.

Small-scale projects[edit]

A no-mow zone is a landscape alternative that does not require construction activities. (Source: Aquafor Beech)
A student helps with planting at Fletchers Creek Senior School. Small-scale LID projects are a great way to engage with the next generation of environmental stewards. Source: CVC

Starting with small-scale projects is a good strategy to increase public interest in LID practices, gauge municipal support, and gain retrofit experience. Small-scale projects include retrofitting your site with landscape alternatives, rain barrels, enhancements of existing swales, or using pollution prevention strategies and practices. Small-scale projects require fewer resources and a smaller project budget:

  • They do not require integration into capital works projects
  • Engineering consultants are not required
  • Contractors may not be not required
  • External approvals are not required
  • Consultation with the public is limited

Due to less financial commitment, it can be easier to build colleague support and to gain supervisor approval for small-scale projects. However, small-scale projects like landscape alternatives and pollution prevention may not be easily identified as LID practices by the public. Your project team should consider establishing educational signage to inform the public.

Pollution prevention (P2) projects are great small-scale projects for municipal facilities, such as schools and public works yards. Many P2 techniques and strategies do not require construction, consultants or contractors. In fact, simply adding signage to a site is a simple and easy to implement pollution prevention at municipal facilities.

A successful small-scale LID retrofit project is a good indication that you are ready to take on a more intensive retrofit project. You now know the resources that are available and understand the internal municipal processes required to move a LID project from planning to finished product.

Large-scale projects[edit]

When installing new parks equipment, consider whether the LID practices can be integrated into the design. Here a bioswale has been built into the landscape between a playground and sidewalk. (Source: CVC)

Large-scale projects require significantly more effort, budget and staff than small-scale projects. Large-scale LID practices include:

Consider a large-scale project if your municipality, school or place of worship would like to be a leader in sustainability. Large-scale projects are often highly visible and attract more public attention. Large-scale projects may also be the only solution to site-specific challenges. For example, if the parking lot on your site does not have existing stormwater controls, small-scale projects are not likely to fully achieve compliance with water quality and quantity objectives. Consider using an infiltration chamber or bioswale project to meet those objectives. Before starting a large-scale retrofit project, consider the following distinctions that set these retrofits apart from small-scale projects.

Integration with capital works programs[edit]

Most large-scale LID retrofits must function with existing site infrastructure, such as storm sewers, catch basins, and pavement systems. The construction of large-scale LID practices often requires these systems to be removed, exposed, or replaced. The best time for this type of project to occur is when an infrastructure replacement or rehabilitation project is already planned.

When LID retrofits are worked into other construction projects, such as parking lot repaving, or grading or drainage improvements, there can be substantial cost savings. Whether big or small, every municipality, school and place of worship spends relatively large sums of money and substantial time planning for major capital projects. This includes redevelopment of public buildings and spaces. Many communities which have undertaken retrofits recognize that even if a relatively small portion of the project funds goes towards LID retrofits, they can retrofit large impervious surfaces and avoid new stormwater management infrastructure projects.

Municipal facility rehabilitation is typically forecast well in advance of the project. Parking lot paving is typically worked into municipal budgets based on expected life cycle and observed wear. As such, funds may be set aside prior to the project planning phases. Long-term forecast budgets may also be available for site revitalization or expansion. These budget forecasts provide opportunities to compare the capital and life-cycle costs and benefits of conventional construction projects against LID retrofits.

Regulatory compliance[edit]

The objectives, technologies and standard practices associated with stormwater management are constantly evolving. It is unlikely that the stormwater management practices on your site meet modern industry standards. When you are making changes to your site, it is important to stay ahead of regulation. Your school, park, place of worship or municipal facility may not be required to improve on-site stormwater management infrastructure, but those retrofits can be beneficial and save money and time over the long term. Consider both current and future water regulations which may affect your property. Consulting with your municipality will help you determine if LID retrofits can reduce taxes or prevent costly upgrades required at a later date.

Involvement of consultants and contractors[edit]

Consultants are required for large-scale retrofit projects, specifically for the final screening of options, pre-design, detailed design, tender and contract documents, construction supervision and administration, and assumption and verification. Site contractors are also required for large-scale LID retrofits.

Ideally, contractors should be pre-qualified based on previous experience with similar LID projects. Remember, the contractor with the lowest bid does not necessarily deliver the best product.

Intensive public consultation[edit]

Stakeholders must be closely involved in the retrofit process for large-scale LID projects. These projects have longer construction windows, may have significant impacts on long term public use patterns of the site and will have significantly higher costs. Gaining public insight before LID implementation can help address public concerns and information gaps, as well as identify public supporters and champions. Public consultation can help designers tailor the project to address community concerns, values and use-patterns.

External approvals[edit]

Large-scale retrofits may require a variety of approvals at the municipal, watershed, provincial, and/or federal level. Since LID is still relatively new, you may encounter policies or bylaws that present barriers to LID retrofit projects. Alternatively, the municipality may have to amend or enforce some policies and bylaws to facilitate the implementation of LID projects on your site.

Parks[edit]

The bioretention area installed at O’Connor Park in Mississauga is part of a stormwater management system that treats parking lot runoff prior to discharging to a local wetland. (Source: CVC)
Urban parkettes may look small, but they have the potential to treat a large surface area of road. Typical ratios of impervious drainage area to a bioretention range from 5:1 to 15:1. (Source: CVC)
The road surface (left) contributes significantly more stormwater pollutants than the parkland area (right). To achieve maximum watershed benefit a designer could consider accepting runoff from this external area. (Source: CVC)


Parks range from simple parcels of municipal property to complex outdoor recreational facilities that include parking, sidewalks, trails, sports fields, field houses, operations facilities and washrooms. Each distinct area of your site can be a source for runoff (referred to as a ‘source area’). Target these areas when introducing LID in your park.

Targeting hard surfaces[edit]

Hard surfaces like parking lots and internal driveways are the most obvious targets for both stormwater quality and water balance improvements. These features produce more runoff than any other area on your site. Runoff from parking lots and driveways is typically more polluted than other source areas. Common water quality concerns include sand and salt from winter de-icing operations, hydrocarbons (gasoline) and heavy metals from vehicle breakdowns.

Runoff from vegetated areas of parks will be relatively clean and more closely matches the natural water balance. On municipal park properties, hard surfaces are usually located adjacent to pervious areas such as lawns, gardens or naturalized areas. This makes parks an ideal location for a LID retrofit. Where grading allows, you can construct bioswales and bioretention areas in these green areas to pre-treat water prior to infiltration.

You can also design parking surfaces and internal roadways as infiltration systems using permeable pavement. This retrofit strategy can be combined with other LID practices. Pathways paved with permeable pavements are another LID option for your park. They reduce runoff volumes and encourage on-site infiltration. Exfiltration trenches are a viable option on many parks sites as well, as they provide an alternative to conventional conveyance systems (such as storm sewers). They encourage infiltration from hard surfaces and can be used to convey water to other LID features.

Accepting drainage from off-site areas[edit]

Does municipally owned land drain into your retrofit site? If so, this is an opportunity to provide stormwater controls for these areas. Roads are the most common source of runoff from external properties into parks. Treating municipal road runoff in a park requires planning input from municipal roads department staff. For these projects, the team must understand how all road activities, including winter maintenance and potential roadwork, will affect the operation of LID practices in the park.

Inter-municipal transfer of funds[edit]

Integrating LID practices into the municipal stormwater management framework may require a change in how municipal funds are managed. Traditional stormwater management maintenance resources and funds may have to be transferred to a more landscape-based stormwater management maintenance program. Instead of infrequent but expensive stormwater management pond sediment removal operations, time and resources would be spent on more frequent but inexpensive maintenance projects, including pruning and weeding bioretention practices or sweeping permeable pavement. Municipalities generally have the required staff and infrastructure within departments (e.g. arborists and horticulturalists in parks departments) to manage the maintenance of LID measures. However, funding this maintenance may require a transfer of funding and additional training. The federal Gas Tax Fund (GTF) is another funding option for LID retrofits. This federal transfer provides long-term funding for municipalities to build and revitalize public infrastructure. Up to 30% of a municipality's yearly GTF allotment can be used for stormwater management.

Source Areas[edit]

The best LID option for your site will depend what types of source areas are present. Source areas may include:

Source areas within a typical park
  • Active use areas
  • Passive use areas
  • Pedestrian walkways
  • Internal driveways
  • Parking lots

On park sites, pollution prevention is often associated with changes to operations and maintenance practices and has not been included in the table below. Options and implementation strategies for a few of these source areas will give you some ideas for your park site.

LID opportunities in parks
(** = Common, * = Possible, o = Unusual)
Source area Permeable pavements Bioretention Enhanced grass swales Bioswales Infiltration trenches and chambers Exfiltration trenches Landscape alternatives Prefabricated modules
Active use area ** o * * ** * o o
Passive use area o ** ** ** ** ** ** **
Pedestrian walkway ** ** ** ** ** * * o
Internal driveway ** ** ** ** ** ** o *
Parking lot ** ** ** ** ** ** o **
When installing new parks equipment, consider whether the LID practices can be integrated into the design. Here a bioswale has been built into the landscape between a playground and sidewalk. (Source: CVC)

Municipal facilities[edit]

Each distinct area of your site can be a source for runoff (referred to as a ‘source area’). Target these areas when introducing LID in your municipal facility.

Targeting hard surfaces[edit]

Municipal facilities have large parking lots to accommodate public demand. Parking areas represent the most significant source of pollutant loading from these sites and contribute significantly to increased runoff rates in comparison to natural conditions. Parking lots include areas for parking, areas for driving, and islands or landscape planters used for calming traffic, directing vehicles and improving pedestrian safety.

LID practices can be incorporated into all areas of a parking lot. You can use bioretention in parking lot islands and along the lot perimeter. Standard curbs with small cut-outs (called ‘curb cuts’) can allow water to easily enter biorentention practices while also preventing damage from cars.

Bioswales are excellent options in parking lot islands or along lot perimeters. Parking lots with existing perimeter ditching are ideal for bioswale integration due to their extended continuous flow path.

Prefabricated modular infiltration chambers are gaining acceptance for their easy integration with parking lot functions. These subsurface systems are typically installed over a coarse granular reservoir to provide storage and allow infiltration into native soils. Infiltration chambers under conventional asphalt system work well on sites where parking demand and other site uses do not allow space for a stormwater feature.

Stormwater planters beautify this building entrance. The entrance receives a lot of traffic during business hours, making it an ideal location for a high visibility LID practice. (Source: Aquafor Beech)

Permeable pavements are also an option in large municipal parking lots. Pervious concrete, permeable interlocking concrete pavers, and porous asphalt can detain stormwater and increase infiltration.

Municipal facilities provide excellent opportunities for integrating rainwater harvesting systems. Rainwater harvesting systems have two requirements: an area for catchment of relatively clean runoff and a nearby demand for water usage. Municipal facilities often have large rooftop areas producing relatively clean runoff. Installing a cistern internal to the building or buried adjacent to the building can provide a sustainable source of water for site irrigation needs for landscaped areas, recreational fields and indoor use (e.g. flushing toilets and urinals).

Targeting highly visible areas[edit]

If your LID integration strategy involves highly visible LID practices, consider targeting areas with high-volume pedestrian traffic. This can help promote LID's visibility among the public and increase support for future LID projects.

Targeting pollution prevention opportunities[edit]

On some municipal sites, pollution prevention techniques and strategies are the best approaches to mitigating the environmental impact of your site. Retrofits of municipal works yards require a different approach than other land uses discussed in this guide. Works yards do not offer substantial opportunities for public interaction. LID retrofits should focus primarily on reducing pollution generated on-site. Fueling stations, waste storage areas, truck washing stations, sand and salt storage, staging areas and water conveyance features are ideal for pollution prevention.

Source areas[edit]

The best LID option for your site will depend what source areas are present. Types of source areas include:

Source areas within a typical community centre.
  • Active use areas
  • Passive use areas
  • Pedestrian walkways
  • Internal driveways
  • Parking lots

On municipal sites, pollution prevention is often associated with changes to operations and maintenance practices and has not been included in the table below.

LID opportunities in municipal buildings
(** = Common, * = Possible, o = Unusual)
Source area Permeable pavements Bioretention Enhanced grass swales / bioswales Green roofs Soakaways and infiltration chambers Perforated pipe systems Rainwater harvesting Landscape alternatives Prefabricated modules Pollution prevention
Active use area ** ** ** o ** * o * o **
Passive use area o ** * o ** ** o ** ** **
Pedestrian walkway ** ** ** o ** * o * * **
Internal driveway ** ** ** o ** ** o o ** **
Parking lot ** ** ** o ** ** o o ** **
Building * * * ** ** * ** o o **

Schools[edit]

The Peel District School Board's Adult Education Centre South school partnered with the City of Mississauga to manage runoff from the adjacent street, Elm Drive, on their property. This partnership benefits the City by giving it space to provide an enhanced level of stormwater treatment, and benefited the school through the construction of new parking lay-bys for students. The site is maintained by the City of Mississauga. Source: CVC

Each distinct area of your site can be a source for runoff (referred to as a ‘source area’). These areas should be targeted when introducing LID at your school.

Targeting hard surfaces[edit]

Parking areas represent the most significant source of pollutant loading from school sites and contribute significantly to increased runoff rates in comparison to natural conditions. Parking lots of all sizes can be targeted for permeable pavement retrofits. As an added benefit, permeable pavement systems have a longer lifespan compared to conventional asphalt. High schools often have large parking lots where the capacity outweighs the demand. These areas represent opportunities to install bioswales or bioretention areas in parking lot islands. Standard curbs with small cut-outs (called ‘curb cuts’) can allow water to easily enter biorentention practices while also preventing damage from cars. Often the existing drainage patterns and catch basin locations can be preserved and integrated into the design. These practices will also function to improve pedestrian safety and calm traffic.

Other types of infiltrating practices like infiltration chambers are gaining acceptance for their easy integration with parking lot functions. These subsurface systems are typically installed over a coarse granular reservoir to provide storage and allow infiltration into native soils. Infiltration chambers under conventional asphalt systems work well on sites where parking demand does not allow space for a stormwater feature. Grassed areas adjacent the parking lots are ideal areas to implement bioswales or bioretention areas. Perforated pipe systems may also work in areas adjacent to parking lots.

Roof options[edit]

Schools typically have large flat roofs that produce a significant amount of runoff that is drained internally via rain leaders. Schools also consume large quantities of water for flushing toilets and urinals. Rainwater harvesting systems can tackle both of these issues by intercepting this rooftop runoff and re-using it for toilet flushing as well as outdoor irrigation. This option has the benefit providing an ongoing financial benefit through reduced water bills. Roof runoff can also be directed to soakaways located on passive use areas around the building. As this runoff comes into contact with fewer hard surfaces, it produces better quality runoff than roads and does not require pretreatment devices. Green roof retrofits are another retrofit option for schools. When applying for external funding from organizations, highlight the fact that green roofs reduce energy usage by providing insulation during the winter and evaporative cooling during the summer.

Pollution prevention (P2)[edit]

On school sites, P2 strategies and practices, such as modifying de-icing programs and isolating drainage from waste storage areas, can be applied to operations and maintenance activities. Discuss these changes with your school board and operations staff.

School board partnerships with municipalities[edit]

LID practices located on school grounds can also be used to treat stormwater from external properties. These partnership opportunities give schools the potential to create new revenue. Accepting and treating runoff on your existing property can make funds available through:

  • Contributions to capital projects like parking lot rehabilitations which include rain gardens, permeable pavements, or subsurface infiltration facilities
  • Ongoing revenues from long-term land leases to accommodate surface or subsurface LID retrofits
  • Funds for maintenance of on-site LIDs

The table below identifies the LID practices that are common, possible and unlikely options for the source areas that you are likely to find on your school site. These source areas are:

Source areas within a typical school site.
  • Active use area
  • Passive use area
  • Pedestrian walkway
  • Internal driveway
  • Parking lot


See the landforms of a school picture on the right for ideas on how to target these areas. The table below gives a more detailed breakdown of LID options for different source areas.

LID opportunities at schools
(** = Common, * = Possible, o = Unusual)
Source area Permeable pavements Bioretention Enhanced grass swales / bioswales Green roofs Soakaways and infiltration trenches Perforated pipe systems Rainwater harvesting Landscape alternatives Prefabricated modules Pollution prevention
Active use area ** ** ** o ** * o * o **
Passive use area o ** * o ** ** o ** ** **
Pedestrian walkway ** ** ** o ** * o * o **
Internal driveway ** ** ** o ** ** o o * **
Parking lot ** ** ** o ** ** o o ** **
Building * * * ** ** * ** o o **

Places of worship[edit]

Each distinct area of a place of worship can be a source for runoff (referred to as a ‘source area’). One or more of these areas should be targeted when introducing LID at your place of worship.

Targeting hard surfaces[edit]

Hard surfaces such as parking lots are a great opportunity to implement LID. Parking lots are the main source of runoff and represent the most significant source of stormwater pollutants coming from your site. Parking lots at places of worship are typically busy only on select days of the week when groups gather for prayer or other community activities. Due to this intermittent schedule, parking lots at these facilities are often rented for other purposes during times of low usage. On sites where peak demand does not approach the total capacity of the lot, consider reducing the parking surface. Retrofit options for these large parking lot areas include permeable pavement, bioswales and bioretention areas. A benefit of permeable pavement systems is that they often have a longer lifespan than conventional infrastructure. The freeze-thaw cycle of the Ontario climate is tough on pavement. Frost heaving and slumping can cause cracks and potholes because of the expansion and contraction of water. The expected lifespan for conventional asphalt pavement in a northern climate, such as Ontario, is approximately 15 to 20 years. A well-maintained porous asphalt system can last for over 30 years, and permeable interlocking concrete pavers can have a design life of 20 to 25 years or greater.

Prefabricated modular infiltration chambers are gaining acceptance because they are easy to integrate with parking lot functions. These subsurface systems are typically installed over a coarse granular reservoir to provide water storage and allow infiltration into native soils. Infiltration chambers under conventional asphalt systems work well on sites where parking demand does not allow space for a stormwater feature.

Using LID techniques to manage stormwater can also eliminate or reduce the need for an on-site storm sewer system. By eliminating piping, failure points in the pavement, such as areas around catch basins and manholes, can be eliminated. A design that does not use storm sewers also negates the need to replace on-site piping, thereby saving long-term infrastructure replacement costs.

Landscaped areas[edit]

Landscaped or lawn areas adjacent to the parking lot or building present opportunities for implementation of LID practices such as bioswales and bioretention areas. These areas typically accept runoff from nearby hard surfaces and provide water quality and water balance benefits.

Roof options[edit]

Rainwater harvesting systems can be simple or complex depending on the architecture and roof drainage patterns of your building. Many places of worship have peaked roofs with piping to convey water from the rooftop. If your site is set up this way, it can be easy to integrate harvesting systems into the landscape surrounding your building.

Roof runoff can also be directed to soakaways located on passive use areas around your building. Due to the relatively good quality of this runoff, pre-treatment devices are not required.

Source Areas[edit]

The LID option that best fits your site will depend what types of source areas are present. Types of source areas include:

Source areas within a typical place of worship
  • Active use area
  • Passive use area
  • Pedestrian walkway
  • Internal driveway
  • Parking lot

At places of worship, pollution prevention is often associated with changes to operations and maintenance practices and has not been included in the table below.

LID opportunities at Places of Worship
(** = Common, * = Possible, o = Unusual)
Source area Permeable pavements Bioretention Enhanced grass swales / bioswales Green roofs Soakaways and infiltration chambers Perforated pipe systems Rainwater harvesting Landscape alternatives Prefabricated modules Pollution prevention
Active use area ** ** ** o ** * o * o o
Passive use area o ** * o ** ** o ** ** o
Pedestrian walkway ** ** ** o ** * o * o o
Internal driveway ** ** ** o ** ** o o * *
Parking lot ** ** ** o ** ** o o ** *
Building * * * ** ** * ** o o *