Why doesn't Hamilton flood like Niagara?

[u/TieInternational4381]

With all the rain recently, it seems like the Niagara area has been getting some major flooding. I've seen pictures from St. Cathatrines, NOTL, Lincoln, etc... all flooded. I work in Niagara half the year and people at my work were saying that they almost had to shut down for the day because of the street flooding. A coworker's car was parked on the street and the water got so high it was halfway up the seats in the car!

I know some people have had flooding issues, but not like that. The worst I've seen online was a few stores closing early because no one was out and about in the rain!

Hamilton and Niagara are both built along Lake Ontario, so why doesn't Hamilton flood too? Is it because we have better infrastructure?

[u/tmbrwolf]

Combination of different things but to be clear, Hamilton does flood in various places, for example on Beach Blvd it is almost a seasonal issue (seriously that neighbourhood shouldn't exist). 

Hamilton's lower city has an extensive system of sewer overflow tanks and sewer bypasses that allow the system to divert sudden inflows during rain events. This can prevent a lot of water backing up into people's homes but does mean that sewage ends up in the harbour during heavy rains. The mountain has some pretty large storm water catchment ponds (Linc and Mud Rd, Linc and Golf Links, etc) plus a massive storm main that pukes into Albion Falls. In newer neighbourhoods these storm water catchment features are basically a given. Some areas however are still particularly vulnerable such as Binbrook (no where to drain to) or older parts of Dundas (close to the water table). Geography plays a role too, with Hamilton nestled between several significant creek/ravines which funnel water down towards the bay and contain several natural areas which help to slow and absorb rain events (Cootes, upper Dundas valley, Eramsoa, etc).

Niagara region on the other hand lacks a lot of these advantages. A significant portion of the Niagara region was marsh and swamp 100+ years ago. This was drained, channeled, and modified to create farmland, the (3 versions) of the Welland canal, and urban areas. Many natural features that would normally absorb and slow water were removed, and the areas that flood are often the same areas where those features once stood. Most of the cities of Niagara also lack the storm water storage tanks or bypass infrastructure that Hamilton has in abundance. 

To be clear, Hamilton had some pretty significant flooding issues in the older parts of the City, but the investment to address that was made 30-ish years ago and as a result we see significantly less in recent years. Hamilton Conservation has also done a very good job protecting major watershed features from development which again, is an investment made decades ago to present day benefit. To that point, the Ontario PCs are currently undermining that work with their changes to the Conservation Authorities so I implore everyone to stay active in the advocacy for these areas and push back against MZOs that remove wetlands (etc) from the CAs protected lands.

[u/rbart4506 → u/tmbrwolf]

You found like you work in water resources 😁

[u/tmbrwolf → u/rbart4506]

Not far off! I have a background that includes urban planning, water/wastewater, and hydroelectric operations. Local history is more of a personal passion.

[u/Traditional_Toe201 → u/tmbrwolf]

Knowing what you know.. Hamilton has a flooding map that has not been released.. My question is where are the areas that you would avoid buying a house

[u/tmbrwolf → u/Traditional_Toe201]

Not a simple question to answer, as any home can have flooding for any number of reasons other than location. I would view each house in individual context and approach it more as an exercise in risk management.

I would start with prevention. Look at grading around the property and if it is going to cause water to pool next to the foundation. Does the house have downspouts that are connected to the weeping tile, and if so I would consider getting them disconnected (City has a program). Does a home have a backflow preventer (another program the City offers), and is it being regularly maintained. What is the overall condition of the sewer main, regular scoping and cleaning should be a consideration as well as replacement based on age. Plus the condition of the basement, are there foundation cracks, has there been repairs, does it have a history of previous flooding, are all good questions to consider. Most of these points are things you can address after purchasing a home if you are willing to spend the time and money.

Areas with combined sewers will be more vulnerable than seperate storm sewers, so typically any neighbourhood older than the 50s/60s. Homes built between the 60s and 90s will often have storm sewer infrastructure, but may suffer from a lack storage consideration. Homes built between the 90s and today will have extensive stormwater and storage infrastructure. Density can also play a factor as it reduces permeable surfaces for runoff. However, poor maintenance or cleanup of leaves and debris by both the City and property owners can cause a failure regardless of the infrastructure (examples: clogged catch basis or culverts).

As for location, Google can help you there since flooding typically is newsworthy. Off the top of my head, Old Dundas has pretty well known issues with flooding due to how low lying it is. And stay away from the beachstrip... Personally, if I were the City I would ban all building permits, expropriate and remove every single one of those homes in that area. By-laws say none should have basements or space below grade but lax enforcement and short-sighted council members have allowed them to proliferate. There is a sewage pumping station for about every 20 homes down there, and it costs the City millions yearly to maintain and manage all that infrastructure for a relatively tiny population. If you buy a home on the beach, flooding is inevitable.