LID Case Studies

Overview

This page is a repository of recent case studies that the Sustainable Technologies Evaluation Program (STEP) have conducted over the past two decades or so. Keep your eye on this page as new projects wrap up and technical briefs or reports are developed they will be added to this page.

Each of the documents are separated by the LID BMP feature that was studied / monitored or built, several of these documents will appear several times throughout this page as many have information on multiple LIDs' performance.

Bioretention

This report by TRCA found several stormwater management benefits by incorporating several LID principles Bioretention, Infiltration trenches/Infiltration chambers, and Enhanced grass swales into sustainable functional design in an underutilized space, now named the 'Bentway' under Toronto's Gardiner Expressway. This allowed for dual functioning of a public recreational area and suitable stormwater management. Read more by clicking the button above.

This report by TRCA discusses the recent 'Markham Municipal Green Road Pilot Project' that was established between 2015 - 2018 and which is located on Vanni Avenue, south east of the intersection of 14th Avenue and Middlefield Rd. in a a mixed use residential and commercial property area. The specially designed road includes multiple low impact development (LID) technologies, including Permeable paver boulevards, Bioretention and Infiltration trenches/galleries underlain beneath the bioretention features to manage stormwater at the source. To learn more about this "Green Street" read the project brief by clicking the button above.

This report by CVC highlights the benefits of a multi-LID retrofit on a mixed-use street with residential homes and an education centre on Elm Drive in Mississauga. The retrofit included, a Permeable pavement sidewalk and parking layby along with six Bioretention cells connected with an underdrain. The site now provides stormwater treatment by improving the quality of stormwater discharged (thermal mitigation, reduction in runoff volume to storm sewers, etc.) to Cooksville Creek. Read more by clicking the button above.

This report by CVC provides a thorough overview of the monitoring work done at the Imax corporate Headquarters, located in Mississauga, ON. The parking lot was expanded and retrofitted with a combination of traditional asphalt and permeable pavement. The asphalt runoff drains to one of three vegetated bioretention units on site. The The parking lot runoff is collected, absorbed and filtered by these LID practices before entering a wetland adjacent to the parking lot. Read more about these features performance over this multi-year study by clicking the button above.

This report by TRCA highlights the first pilot project by Toronto Green Streets completed as a partnership between City Planning and Toronto Water. The site was first identified as a priority location for improving traffic flow and pedestrian safety in 2014, and the City took the opportunity to retrofit it as a green infrastructure demonstration site. For the project, the right turn lane from Fairford Avenue eastbound to Coxwell Avenue was eliminated and the space was used to build a landscaped bioretention area and public seating. Read more about how this project was spurred by community request for pedestrian improvements to the area and showcased the aesthetic and instrumental value of the new parquetted designed with a bioretention cell on site, by clicking the button above.

This report by TRCA discusses the various Low Impact Development (LID) technologies used in key areas of interest throughout UOIT's campus (located in Oshawa, ON.), to both mitigate the impacts of the development and to green the campus. The processes are transparent to the campus community providing valuable visible lessons for students and faculty. The LID technologies used include Bioretention, linear Wetlands, Green roofs and Rainwater harvesting, all designed to reduce runoff volumes and pollutant loads to the adjacent ravine.

Read more about Bioretention here.

Stormwater Tree Trenches

The Sustainable Sidewalk project was initiated as a solution to address the disturbance of street tree roots associated with the removal of sidewalks for utility cuts. A working group with participants from various City of Toronto Divisions was formed and the group decided to use soil cells for a stormwater tree trench system (bioretention) and in the fall of 2008 constructed The 'Queensway Sustainable Sidewalk Pilot Project'. Monitoring results from the study found that the soils were able to reduce TSS (>80%) and heavy metal concentrations in the road run off that entered the system. Also the outlet flow meter did not show any flow release after a rainfall of 3 mm that was preceded by a period of no rain, showcasing the systems ability to mitigate excess stormwater runoff in the heavily urbanized location.

Read more about Stormwater Tree Trenches here.

Wetlands

The purpose of this document authored by TRCA and CVC is to inform the need for, and the design of, mitigation measures to ensure a minimal difference between the post-development and pre-development water balance of a wetland. This Modelling Document provides an overview of wetland hydrology modelling, the strengths and weaknesses of various hydrological models, and the information that needs to be included in a wetland feature-based water analysis report. Read more about the importance of choosing the correct hydrological model and inclusion of the pertinent information required for a proper water analysis report by clicking the button above.

The following document from TRCA helps user better determine the appropriate model to simulate wetland hydrology, wetland storage dynamics, and the representation of stormwater management and low impact development (LID) facilities, etc. This document is an appendix to the previously mentioned, Wetland Water Balance Modelling Guidance Document and is intended to be a resource for modelers to help them make more informed decisions in modelling wetland water balance scenarios. Read more about this valuable resource for modelers to consult for applications requiring a wetland water balance, by clicking the button above.

Read more about Wetlands here.

Rain Garden

The Kleinburg Starbucks Fusion Garden is the first one York Region has established as part of their Fusion Gardening® pilot project. The case study discusses the benefits of a Rain garden, which allows for a beautiful tailored aesthetic for the owner, while also serving as a more absorbent landscape that reduces stormwater runoff and conserves water on site. The garden also uses an Infiltration trench for irrigating the planting bed and Permeable pavement on the pedestrian paths and seating area. Read more about this design concept by clicking the button above.

Read more about Rain gardens here.

Sustainable Technologies Evaluation Program

Low 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.

Best management practice. State of the art methods or techniques used to manage the quantity and improve the quality of wet weather flow. BMPs include: source, conveyance and end-of-pipe controls.

A shallow excavated surface depression containing prepared filter media, mulch, and planted with selected vegetation.

Toronto and Region Conservation Authority

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.

A shallow excavated surface depression containing prepared filter media, mulch, and planted with selected vegetation.

Credit Valley Conservation

The portion of water precipitated onto a catchment area, which then 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.

A mixture of mineral aggregates bound with bituminous materials, used in the construction and maintenance of paved surfaces.

An 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.

A vegetated area such as a bog, fen, marsh, or swamp, where the soil or root zone is saturated for part of the year.

Natural vegetation and vegetative technologies in urban settings such as: urban forests; green roofs; green walls; green spaces; rain gardens; bioswales; community gardens; natural and engineered wetlands and stormwater management ponds; and porous pavement systems. These systems are designed to provide multiple benefits, such as moderate temperatures, clean air and water, and improve aesthetics.

Low impact development is a stormwater management and land development strategy applied at the parcel and subdivision scale that emphasizes conservation and use of on-site natural features integrated with engineered, small scale hydrologic controls to more closely mimic pre-development hydrologic functions.

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.

Total suspended solids

refers to the characteristics and functions of a system prior to urban development.

The accounting of inflow and outflow of water in a system according to the components of the hydrologic cycle.

Relating to the properties, distribution and effects of water on and below the earth’s surface, and in the atmosphere.