Low Impact Development


Low Impact Development (LID) practices are increasingly being used to deal with problems related to urban stormwater runoff including erosion, sedimentation and pollution.

The traditional approach to dealing with stormwater has been to move it away from city streets as quickly and efficiently as possible. This results in large volumes of water entering our waterways at high velocities, carrying the pollutants picked up along the way.

LID, by contrast, deals with stormwater by mimicking natural water cycles. It increases the infiltration of stormwater into the soil, where it can be filtered and/or absorbed by plants. LID is a lower-cost alternative to conventional grey infrastructure and provides a number of ecological, economic and social benefits.

Examples of LID include:

Bond Lake Bioswale
Bioswales, like this one in the Bond Lake area of Richmond Hill, are one commonly-used type of low impact development (LID) solution.

The benefits of low impact development include:

  • Improved water quality
  • Improved groundwater recharge
  • Reduced number of costly flooding events
  • Reduced urban heat island effect

  • Restored aquatic habitat
  • Increased habitat for pollinators and other wildlife
  • Enhanced neighbourhood beauty


The number of LID installations (including hybrid LID/conventional stormwater infrastructure) has been growing in Toronto over the last several years. Both the public sector and the private land development industry have been adopting LID practices under various standards and legislative measures.

Toronto and Region Conservation Authority (TRCA) is currently working to incorporate LID into its Restoration Projects portfolio.


Black Creek Pioneer Village Rain Garden

In 2016, TRCA constructed a rain garden just outside Charles Irvin’s Weaver’s Shop at Black Creek Pioneer Village.

Populated with Black-eyed Susan, Red Bergamot, Blue Flag Iris and Pearly Everlasting, this colourful garden captures roof run-off and retains stormwater on site before it exits into a storm drain.

rain garden at Black Creek Pioneer Village
Charles Irvin’s Weaver’s Shop at Black Creek Pioneer Village during (top) and after (bottom) the construction of a rain garden.

Glencrest Park Rain Garden

A partnership between City of Markham and TRCA’s Sustainable Neighbourhood Action Program (SNAP) resulted in the construction of a rain garden at Glencrest Park as part of a larger park renewal project.

The main objectives of the project were to:

  • Naturalize the park
  • Improve hydrologic function of the low-lying area of the park
  • Improve the park’s appearance and usability for the community

The rain garden also provides habitat for urban wildlife, reduces lawn cutting needs, and offers the public health benefits associated with greater access to and interaction with nature.

The new Glencrest Park, with its modern playground, trail system and rain garden, opened officially on May 26, 2018.

TRCA rain garden project at Glencrest Park
The Glencrest Park Rain Garden project, before (left) and after (right).