Difference between revisions of "LID opportunities at municipal facilities"

From LID SWM Planning and Design Guide
Jump to: navigation, search
m (Source areas)
m (Source areas)
Line 60: Line 60:
 
|}
 
|}
  
[[File:Figure 4.3.7 (G-to-G Public Lands).JPG|thumb|Source areas within a typical park.]]
+
[[File:Figure 4.3.7 (G-to-G Public Lands).JPG|thumb|Source areas within a typical community centre.]]
  
 
===Small-scale projects===
 
===Small-scale projects===

Revision as of 17:46, 18 December 2017

Each distinct area of your site can be a source for runoffThat potion of the water precipitated onto a catchment area, which flows as surface discharge from the catchment area past a specified point.Water from rain, snow melt, or irrigation that flows over the land surface. (referred to as a ‘source areaThe land draining to a single reference point (usually a structural BMP); similar to a subwatershed, but on a smaller scale.’). Target these areas when introducing LIDLow Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting. in your municipal facility.

Targeting hard surfaces

Municipal facilities have large parking lots to accommodate public demand. Parking areas represent the most significant source of pollutant loadingThe total mass of a pollutant entering a waterbody over a defined time period.The net amount of something (e.g. chemical, such as phosphorus), calculated as the product of concentration and volume in a given time. Some BMPs significantly reduce loading of pollutants to the environment by reducing volume more so than concentration. from these sites and contribute significantly to increased runoffThat potion of the water precipitated onto a catchment area, which flows as surface discharge from the catchment area past a specified point.Water from rain, snow melt, or irrigation that flows over the land surface. 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.

LIDLow Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting. 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 bioswaleLinear bioretention cell designed to convey, treat and attenuate stormwater runoff. The engineered filter media soil mixture and vegetation slows the runoff water to allow sedimentation, filtration through the root zone, evapotranspiration, and infiltration into the underlying native soil. 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 granularGravel, or crushed stone of various size gradations (i.e., diameter), used in construction; void forming material used as bedding and runoff storage reservoirs and underdrains in stormwater infiltration practices. reservoir to provide storage and allow infiltration into native soils. Infiltration chambers under conventional asphaltA mixture of mineral aggregates bound with bituminous materials, used in the construction and maintenance of paved surfaces. 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 LIDLow Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting. practice. (Source: Aquafor Beech)

Permeable paving is also an option in large municipal parking lots. Pervious concrete, permeable interlocking concrete pavers, and porous asphaltA mixture of mineral aggregates bound with bituminous materials, used in the construction and maintenance of paved surfaces. can detain stormwater and increase infiltrationThe slow movement of water into or through a soil or drainage system.Penetration of water through the ground surface..

Municipal facilities provide excellent opportunities for integrating rainwater harvesting systems. Rainwater harvestingThe practice of intercepting, conveying and storing rainwater for future use. Captured rainwater is typically used for outdoor non-potable water uses such as irrigation, or in the building to flush toilets. systems have two requirements: an area for catchmentThe land draining to a single reference point (usually a structural BMP); similar to a subwatershed, but on a smaller scale. of relatively clean runoffThat potion of the water precipitated onto a catchment area, which flows as surface discharge from the catchment area past a specified point.Water from rain, snow melt, or irrigation that flows over the land surface. and a nearby demand for water usage. Municipal facilities often have large rooftop areas producing relatively clean runoffThat potion of the water precipitated onto a catchment area, which flows as surface discharge from the catchment area past a specified point.Water from rain, snow melt, or irrigation that flows over the land surface.. Installing a cisternTank used to store rainwater (typically roof runoff) for later use. internal to the building or buried adjacent to the building can provide a sustainable source of water for site irrigationHuman application of water to agricultural or recreational land for watering purposes. City of Toronto Wet Weather Flow Management November 2006 47 needs for landscaped areas, recreational fields and indoor use (e.g. flushing toilets and urinals).

Targeting highly visible areas

If your LIDLow Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting. integration strategy involves highly visible LIDLow Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting. practices, consider targeting areas with high-volume pedestrian traffic. This can help promote LIDLow Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting.'s visibility among the public and increase support for future LIDLow Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting. projects.

Targeting pollution prevention opportunities

On some municipal sites, pollution prevention techniques and strategies outlined in Chapter 2 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. LIDLow Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting. retrofits should focus primarily on reducing pollution generated on-site. Fuelling stations, waste storage areas, truck washing stations, sandMineral particles which are smaller than 2 mm, and which are free of appreciable quantities of clay and silt. Coarse sand usually designates sand grains with particle size between 0.2 and 0.02 mm. and salt storage, staging areas and water conveyance features are ideal for pollution prevention.

Source areas

The best LIDLow Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting. option for your site will depend what source areas are present. Types of source areas include:

  • 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.

LIDLow Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting. opportunities in municipal buildings
(** = Common, * = Possible, o = Unusual)
Source areaThe land draining to a single reference point (usually a structural BMP); similar to a subwatershed, but on a smaller scale. Permeable pavement 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 * * **
Internal driveway ** ** ** o ** ** o o ** **
Parking lot ** ** ** o ** ** o o ** **
Building * * * ** ** * ** o o **
Source areas within a typical community centre.

Small-scale projects

Starting with small-scale projects is a good strategy to increase public interest in LIDLow Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting. practices, gauge municipal support, and gain retrofit experience. Small-scale projects include retrofitting your site with landscape alternatives or rain barrels, enhancements of existing swalesA shallow constructed channel, often grass-lined, which is used as an alternative to curb and channel, or as a pretreatment to other measures. Swales are generally characterized by a broad top width to depth ratio and gentle grades., 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 capital works

projects

  • Engineering consultants are not required
  • Contractors may not be required
  • External approvals are not required
  • Consultation with the public is limited

Due to this smaller financial commitment, it can be easier to build colleague and supervisor support for small-scale projects.

Pollution prevention (P2) projects are great small-scale projects for municipal facilities like public works yards. To learn more about implementing P2 on your site, refer to the case studies on Armstrong Manufacturing Inc, Bernardi Building Supply Ltd. and Unifay-Fedar Investments in Appendix B.

Many P2 techniques and strategies do not require construction, consultants or contractors. Adding signage to a site is a simple and easy to implement pollution prevention at municipal facilities.

A successful small-scale LIDLow Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting. retrofit project on your municipal site 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 LIDLow Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting. 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 LIDLow Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting. retrofits include:

  • BioretentionA shallow excavated surface depression containing prepared filter media, mulch, and planted with selected vegetation.
  • Enhanced grass swalesA shallow constructed channel, often grass-lined, which is used as an alternative to curb and channel, or as a pretreatment to other measures. Swales are generally characterized by a broad top width to depth ratio and gentle grades.Vegetated, open channels designed to convey, treat and attenuate runoff. Design variations range from simple grass channels, which are designed primarily for conveyance to more complex treatment and volume reduction designs like enhanced grass swales, and dry swales or bioswales.
  • BioswalesLinear bioretention cell designed to convey, treat and attenuate stormwater runoff. The engineered filter media soil mixture and vegetation slows the runoff water to allow sedimentation, filtration through the root zone, evapotranspiration, and infiltration into the underlying native soil.
  • Perforated pipe systems
  • Permeable pavementAn alternative practice to traditional impervious pavement, prevents the generation of runoff by allowing precipitation falling on the surface to infiltrate through the surface course into an underlying stone reservoir and, where suitable conditions exist, into the native soil.
  • Soakaways
  • Infiltration chambers
  • Rainwater harvestingThe practice of intercepting, conveying and storing rainwater for future use. Captured rainwater is typically used for outdoor non-potable water uses such as irrigation, or in the building to flush toilets. (excluding rain barrels)
  • Prefabricated modules
  • Green roofs

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 site infrastructure is at risk as a result of urban flooding, LIDLow Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting. practices that detain large volumes of runoffThat potion of the water precipitated onto a catchment area, which flows as surface discharge from the catchment area past a specified point.Water from rain, snow melt, or irrigation that flows over the land surface. and encourage infiltration are the most viable LIDLow Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting. options. 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 LIDLow Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting. retrofits must function with existing site infrastructure, such as storm sewers, catch basinsGround depression acting as a flow control and water treatment structure, that is normally dry., and pavement systems. The construction of large-scale LIDLow Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting. 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 LIDLow Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting. retrofits are worked into other construction projects, such as parking lot repaving, or grading or drainageNatural or artificial means of intercepting and removing surface or subsurface water (usually by gravity). improvements, there can be substantial cost savings. Whether big or small, every municipality spends relatively large sums of money and substantial time planning for major capital projects. This includes redevelopment of public building and spaces. Many communities who have undertaken retrofits recognize that even if a relatively small portion of the project funds goes towards LIDLow Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting. retrofits, they can retrofit large imperviousA hard surface area (e.g., road, parking area or rooftop) that prevents or retards the infiltration of water into the soil. surfaces and avoid new stormwater management infrastructure projects17.

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 revitalizations or expansions. These budget forecasts provide opportunities to compare the capital and life-cycle costs and benefits of the conventional construction project and LIDLow Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting. retrofit.

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 LIDLow Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting. retrofits. Ideally, contractors should be pre-qualified based on previous experience with similar LIDLow Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting. projects. Remember, the contractor with the lowest bid does not necessarily deliver the best product.

More intensive public consultation

Stakeholders must be closely involved in the retrofit process for large-scale LIDLow Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting. projects. These projects have longer construction windows, may have significant impacts on long-term public use patterns of the site, and will cost significantly more taxpayer dollars.

Gaining public insight in advance of LIDLow Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting. 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. Consultation can also help the design team integrate the LIDLow Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting. practice into the site’s landscape.

External approvals

Large-scale retrofits may require a variety of approvals at the municipal, watershedThe drainage area of a river.An area of land that drains into a river or a lake. The boundary of a watershed is based on the elevation (natural contours) of a landscape., provincial, and/or federal level. Since LIDLow Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting. is still relatively new, you may encounter policies or bylaws that present barriers to LIDLow Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting. retrofit projects. Alternatively, the municipality may have to amend or enforce some policies and bylaws to facilitate the implementation of LIDLow Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting. projects on your site.