Stormwater Management

Stormwater management in Richmond Hill involves operating more than 85 stormwater ponds, 650 km of storm sewers and 18,000 catch basins to store, direct and control stormwater runoff. These efforts protect our community's more than 150 km of streams and rivers, prevents flooding and erosion, and improves water quality. 

What is stormwater runoff and why manage it?

Erosion near Elgin Mills Greenway Trail

Runoff comes from rain and melting snow running off of hard surfaces, such as driveways, parking lots and across all land. In a naturalized setting, runoff will either absorb into the soil or plants or evaporate from areas of open waters eventually making its way into our streams, rivers and lakes slowly over time.

An increase in hard surfaces is causing more runoff to enter our streams, rivers and lakes at an increased rate. Without stormwater management, runoff can flood communities and roads, cause stream erosion and destroy aquatic habitat. Managing this runoff prevents flooding, erosion and improves water quality.

Photo (right): Elgin Mills Greenway, where uncontrolled runoff caused significant erosion within the valleylands and the closure of several trails.

How does a stormwater management facility work?

Runoff enters storm sewers and flows into stormwater management ponds, where it is held before being slowly released into streams, rivers and lakes thereby helping to prevent flooding and erosion. In addition, this process allows sediment and other pollutants to settle to the bottom of the pond increasing the quality of the water being released into our watercourses.

Our more modern stormwater management facilities, such as Pioneer Pond and Rumble Pond have additional controls such as oil grit separators and filtration systems that clean the stormwater runoff before it enters the pond. Native plants and special landscaping materials also help to manage pollution and runoff at these facilities.

Our stormwater management systems

Aerial photo of Rumble PondOur stormwater management systems must meet guidelines and regulations set by authorities, such as the Ontario Ministry of Environment, Conservation and Parks (MECP) and the Toronto and Region Conservation Authority (TRCA).

Ensuring safe and reliable stormwater service is a core municipal responsibility, as such the City is moving towards a comprehensive modelling of the complete stormwater system. Our goal is to gain an understanding of the overall system capacity and constraints, and direction with respect to optimizing the existing system for today and in consideration of climate change, as well as the capacity to model various scenarios when new development is added to the system. The project is expected to be completed in 2023.

A number of the projects from our existing program, including the Pioneer Park Stormwater Management Facility in 2010, the Rumble Pond (pictured above) in 2014 and the Elgin Mills Greenway in 2018, have earned us Provincial and international awards.

Current projects 
Past projects 
  • Elgin Mills Greenway Pond  
  • Beaver Creek Pond
  • Ashfield Pond
  • Harding Pond
  • Don Head West Pond
  • Rumble Pond
  • Pioneer Pond 

Help reduce and improve your runoff

You can help Richmond Hill reduce the amount of runoff getting into our streams. Some ways to lower and improve your runoff footprint include:

  • Using a carwash instead of washing your car in your driveway
  • Cleaning up animal waste and yard waste
  • Using less fertilizer
  • Fixing leaking fluids from your car
  • Using rain barrels to catch roof runoff and using it to water your garden or lawn
  • Disconnecting your roof downspout if it's connected to a storm sewer and redirecting it to your lawn
  • Reducing your use of salt or sand in the winter
  • Getting rid of household hazardous waste properly
  • Choosing native plants that don't require as much watering
  • Checking your sprinklers for leaks
  • Following local rules for lawn watering

Technical information for Developers