Stormwater Management

Be Rain Ready!

The town manages stormwater to make sure there are a range of measures in place to decrease the risk of flooding and to reduce pollution. Stormwater management ensures that our stormwater system protects Oakville residents while preserving our natural environment.

As part of the town’s long-term vision for stormwater management, we are developing a Stormwater Master Plan to assess what has been done—what still needs to be done—and priorities for the future.

Be part of developing the plan and enhancing the quality of life for everyone in Oakville!

Questions or comments:

Kristina Parker
Water Resources Engineer
Development Engineering
905-845-6601 ext. 3889

Stormwater management is more essential than ever

Have you noticed a lot of extreme rainstorms over the last few years? You’re not imagining things. In Southern Ontario, we are experiencing more intense and more frequent rainfall than ever.

As our town continues to grow, develop and redevelop/intensify there is less natural ground for the stormwater to soak into. Instead the stormwater runs onto our roads, driveways, and sidewalks, which can lead to floods. And that’s not all, stormwater releases pollution into our community. Stormwater management practices have improved over time and as such some older neighbourhoods are more vulnerable to flooding.

Fortunately, we’re on the job! We’ve had a stormwater system in place for over fifty years that we continue to enhance. We are now gaining an improved and extensive understanding of our system that will help us address deficiencies and make improvements.

Highlights: Stormwater Management in Oakville

How we manage stormwater in Oakville - Fast Facts

  • Stormwater runoff is rain and melting snow that flows overland. This water is makes its way to Lake Ontario through the town’s stormwater drainage system and private drainage system.
  • The minor drainage system includes catch basins, storm sewers, ditches, swales, and driveway culverts, which are typically sized to handle more frequent storm events such as the 1 in 5 year event (a storm event that statistically has a 20% chance of occurring in any given year).
  • The major drainage system handles flows that are too large for the minor system resulting from infrequent storm events. The major system includes overland flow routes such as road right-of-ways, man-made diversion channels, and natural waterways like the many creeks found throughout Oakville.
  • There are areas within the town that would likely be vulnerable to flooding during extreme rainfall events due in part to the nature of the stormwater management practices considered at the time of development. This flooding can range from nuisance drainage/ponding issues in backyards and ditches to basement flooding.
  • Who does what? There are various ways that flooding can occur and jurisdiction varies for each. Riverine flooding concerns are shared with the Conservation Authority that regulate the creek floodplains. The town-owned minor (storm sewer pipes) and major (overland flow route) storm drainage systems are the responsibility of the town. Flooding related to surcharging sanitary sewers is the responsibility of the Region of Halton.

Stormwater Management, by the numbers

  • The town currently owns and manages 34 stormwater management ponds (SWMPs), plus approximately 25 additional ponds in various stages of development.
  • To support greenfield development in the north end of town, a further 50 ponds are proposed.
  • The town manages and inspects over 350 storm sewer outfalls and approximately 550 km of storm sewer pipes
  • Approximately 8.8 km of shoreline along Lake Ontario and 116 km of open watercourse (streams) are owned and managed by the town.

What can homeowners do – helpful resources

  • Ensure proper drainage around your home to keep water away.
  • On-going maintenance around your home and yard will assist in lowering flooding risks.
  • There are several helpful websites that provide information on protecting your property from flood risk and vulnerability. For further information, including details regarding the Region of Halton’s Basement Flooding Prevention Subsidy Program please visit the websites provided below:
  • Town of Oakville climateXchange event
  • Town of Oakville Emergency Preparedness

Stormwater management ponds (SWMPs)

  • SWMPs control the flow of water. Without these ponds, large amounts of water would enter a stream all at once, causing flooding and eroding soil from the stream banks.
  • SWMPs also improve water quality. The permanent pool of water within the pond allows sediment to settle before water enters the stream. Vegetation in landscaped areas also improves the water quality by helping to filter the sediment.
  • The town carries out inspections and maintenance on SWMPs to ensure they are functioning as intended.
  • Once every five to 10 years the SWMP is cleaned out to remove accumulated sediment to ensure the pond continues to function as intended. This clean out involves draining the SWMP and the use of heavy equipment.
  • Please do not dispose of trash, grass clippings, or fish in the SWMPs and minimize the use of fertilizer.

Visit the stormwater management ponds page for more information.