Quote:
Originally Posted by ScreamingViking
Posting because this issue may be (is likely, it seems to me) related to growth around the airport... and IMO the city needs to think about this stuff, because it will become a larger problem over time as more land is developed.
Looking at that image, it's not hard to imagine why this home got flooded.
Hopefully the coming mitigations will help. Though historically, there was little understanding that building anything on a flood plain was a bad idea...
Floodwaters keep coming. Insurance company won’t pay. Who is to blame? This Glanbrook couple points to a giant new development
‘We’re tapped out,’ Dickenson Road couple says of ruined basement
https://www.thespec.com/news/hamilto...3dddefdd8.html
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This is an unfortunate situation for the homeowners. It also illustrates an example of what I'll call 'told you so' situations where the longer-term cost of suburban development is disproportionately high compared to more compact forms of more urbanized development and the older central city itself.
Building in a floodplain is sometimes unavoidable, especially historically when so many communities formed on river banks and deltas because they were fertile and generally flat and had a freshwater source. But it inherently comes with flooding risk, especially when the proportion of impermeable surfaces steadily increases over time without a concomitant increase in stormwater management infrastructure.
When suburban development typically occurred, including flood-prone areas, it was only required to provide the minimal viable servicing infrastructure, such as stormwater ditches and culverts with some interspersed detention ponds and generally undersized connections to the broader municipal stormwater system. In each instance, the supplied infrastructure was sufficient to meet the codes and by-laws of the time. But taken in aggregate, the patchwork system of subdivision-oriented stormwater infrastructure was not built to the same standard as the more urbanized/older parts of the city with a fully grade-separated stormwater system, albeit one that is, unfortunately, still commonly utilizing a combined stormwater and sewage outflow system in the older parts of a city.
The longer-term challenges of this approach are on display here where new development has, for a variety of reasons, upset the balance and produced runoff that exceeds the capability of the downstream stormwater systems to cope. Couple that with the inherent topographic channeling of a floodplain and it's a real problem with no easy solution. As a result, the City is hiring expensive consultants to study the situation and it will undoubtedly require some quite significant capital investments to mitigate, all while the homeowners are incurring huge financial costs and insurers are balking.
Meanwhile, the City is undertaking expensive infrastructure upgrades and studies throughout the area to keep up with demand, all while grappling with and preparing for a vexing aspect of climate change which is the cycle of increasing periods of hot dry weather, which parches the soil and lowers its permeability, and more intense rainfall events. This cycle, unfortunately, reduces the effectiveness of natural infiltration stormwater management systems like ditches, swales, and detention ponds, exacerbating the likelihood of localized flooding during heavy rainstorms.
So, my point with all of this is that as we are gearing up for another round of suburban development that will result from provincial policies, we
have to significantly increase the capacities and quality of the stormwater management system that is being required in new subdivisions and ensure that these new developments bear the preponderance of costs to upgrade the downstream municipal infrastructure that will be required to service them. A major reason why suburban and exurban development is so cheap is that it's only making a down payment on the true cost of the development to the broader city. When those additional costs are borne, often decades down the line, it is everyone who foots the bill and it's a
large bill. <gestures expansively at our roads>