Currently working on permitting for a property in a Canadian flood zone, and also been on the city side in the past so lotssof experience......
First toughhlove; You are ignoring two huge impacts: the safety of those who will have to rescue you if it floods and b. The cost of bailouts by the government for those hit by flooding. Both are expensive and the rest of the taxpayers don't want to be paying for your refusal to take appropriate measures.
But, appropriate is a very broad term so as an architect what can you do to mitigate the risk? Be creative!
Knowing the 100 and 200 year flood levels is the basis for any discussion. From there plan your response. What would be impacted, is there an escape route, are services above the flood level? As an architect you are legally responsible for areas such as egrrss in a fire, so it surprises me that you want to throw your professional standards out if the window.
Personally, we are formulating a plan that includes raising some buildings and leaving others to flood but with electrical up high. Our scheme doesn't necessarily meet the bylaw as written, but we will argue that it will be safe with minimal risk. But we need the data to back those arguments up for the variance if needed.
I may sound harsh, but the reality is that floods, even near streams, can and do kill people. I've watched several floods in tbe past and seen the devastation. Prove to yourself the risk, and if there is none sleep soundly in your new extension. Good luck!
