Flooding

Understand the different types of flooding and how they impact stormwater management.

Floods can happen anywhere and anytime, especially during heavy thunderstorms. They can damage your home and your belongings. Sewer back-ups occur when the storm or sanitary sewers become too full and the sewage flows backwards into residents’ homes.

By taking the right steps and being prepared, you can help keep your home safe from the effects of flooding.

Contact the Town of Oakville for

  • Catch basin, ditch or culvert flooding
  • Creek  or stormwater management ponds
  • Road or sidewalk water pooling
  • Fallen tree branches or downed trees
  • Property flooding that does not drain away
  • Park, trail, or town facility drainage concerns
  • Road debris

Flood prevention tips

The Government of Canada provides 10 tips to make your home flood-ready and other online resources that help prevent flooding in your home.

  • Ensure your yard slopes away from your house, not towards it.
  • Ensure that eavestroughs (gutters) and downspouts are clear and drain properly.
  • Keep floor drains inside your home clear.
  • Ensure window wells are free of debris.
  • Install weather protection sealant around basement windows and the base of ground-level doors.

Town staff perform a number of activities to ensure the rainwater network operates as planned and that actionable responses are available if unexpected situations arise. These include: 

  • Pre-event activities: 
    • Monitoring, inspection and maintenance – staff  use several weather/flood reporting services, including the Conservation Authorities and use this information to prepare for pre-storm event activities such as patrol inspections and pro-active works. Proactive works include clearing inlets / outlets and pushing back snow banks identified by patrol inspections when potential significant rainfall and/or fast melt scenarios are in the forecast.
  • Service calls
    • All flood related service calls are to be directed to ServiceOakville as this will allow the town to track the event and document activities for post review and/or follow-up.
  • During-event activities: 
    • Emergency support/response – during a storm event, staff monitors service calls and are deployed to inspect, service, support and remedy (where possible) emergency issues that arise such as clearing blockages or cordoning off and securing an area until flood waters subside. 
  • Post event
    • Support/response - staff will respond to flood related service calls to examine cause and address public infrastructure elements if/when found to be the cause or contributor. If simple, the remedy to address the issue will be actioned in a timely manner. Often, an issue requires further review and potential for inclusion in future capital programs. Staff will also clean up roads and rights of way following a flood event where debris and material are left behind once flood waters subside. 
    • Post event reviews - de-briefs are conducted to ensure simple remedies are completed and issues have been resolved and include adding the location to proactive inspection programs; more extensive investigation/engineering review and/or addition to the capital program for longer term improvements.

Homeowners who have in-house flooding in their home should take action quickly and safely.

If you are in immediate danger call 911.

If your basement flooded

  1. Take immediate health and safety precautions. Visit the Halton Region website for information about how to prevent illness and injury.
  2. Call Halton Region at 3-1-1. You can also reach the Halton Region contact centre at 905-825-6000, or toll-free at 1-866-442-5866, TTY: 905-827-9833
  3. Contact your home or business insurance provider.
    • The town does not provide advice to private homeowners about insurance policies. If you do not have home or contents insurance, contact your preferred insurance company or broker to obtain an insurance policy.

Visit Halton Region website for more information on what to do if your basement has flooded.

Stormwater network flooding happens if the amount of rainfall or melting snow is too much for drainage systems to handle. If this happens, storm sewers can backup, roadways and parks fill with water and water may seep into building walls, floors, and back up through sewer pipes. 

Design standards for stormwater management in Ontario have evolved over the years. Oakville's stormwater management network is designed to reduce the risk of flooding. However, communities have different design standards and levels of flooding risk depending on when the community was built.  

Pre-1970 drainage systems were designed to move rainfall runoff as quickly as possible. They focused on flooding of individual developments, but the impacts that resulted from development were generally ignored. As a result, natural drainage systems, such as creeks and lakes were affected by increased flooding, erosion and poorer water quality.  

In the late 1970’s to early 1980’s, a new approach focused on preventing downstream flooding and erosion problems. Stormwater management techniques, such as dry stormwater management ponds, were applied to reduce peak flow discharges from developments. 

In the early 1990's, the watershed planning approach emerged. The key principle being that overall watershed objectives should consider all physical, chemical, and biological criteria that are important to aquatic life and to human health. The use of wet stormwater management ponds became a primary stormwater management technique.

Learn more about stormwater management

Creeks can flood when rain or melting snow causes the creek water levels to rise and spill over its banks into areas next to it. The areas next to the creeks that can be underwater for a period of time are called floodplains.  

If you would like to know if your property is next to a floodplain, or if you're considering construction within or next to a floodplain, you should contact to local regulatory authority.

Contact

Properties near the following creeks should contact Conservation Halton at 905-336-1158, ext. 2227 or envserv@hrca.on.ca:

  • Sheldon Creek
  • Bronte Creek
  • Fourteen Mile Creek
  • McCraney Creek
  • Taplow and Glen Oaks Creeks
  • Sixteen Mile Creek
  • Shannon Creek
  • Munn’s Creek
  • Morrison and Wedgewood Creeks
  • Joshua’s Creek

Properties near Clearview Creek should contact Credit Valley Conservation at 905-670-1615 or planning@creditvalleyca.ca.

Learn more about Oakville's creek flood mitigation studies

Visit the Environmental Projects & Studies page.

Lake Ontario collects water from precipitation, runoff from the surrounding basin, and water from the Niagara River. Lake Ontario flooding happens when high water levels from these water sources making the lake overflow along the shoreline. 

In 2017, this is what happened. 

  • From January to June of 2017, the Niagara River swelled to higher than average levels. 
  • April and May had record-breaking precipitation, including rain and snow, in the Lake Ontario basin.
  • Precipitation added about three quarters of a metre to Lake Ontario through precipitation directly onto the lake surface as well as runoff from the rest of the basin.  
  • Floodwaters along the shores of Lake Ontario closed roads, penetrated homes, destroyed break walls and eroded away shoreline. 
  • Shore-bound residents watched the lake rise almost a meter above its normal levels.  
  • Resulted in Oakville council having to approve $3.8 million to repair damage to its shoreline and harbours.

If you are considering construction on a shoreline property, check with Conservation Halton at 905-336-1158 ext. 2227 or envserv@hrca.on.ca.

Learn more about shoreline protection

Visit the Shoreline page.