On the fifth anniversary of the Calgary flood, Mayor Naheed Nenshi and others highlighted the importance of mitigation work — stressing that there is still lots to be done.
If you want to know anything about how the rivers in Calgary work, there’s only one man to go to: the city’s leader of watershed analysis, Frank Frigo.
Frigo says in the past, the Bow cut a channel right through the middle of what is now downtown and that’s why the city has built a huge berm which doubles as a park near the Peace Bridge.
“This elevated work here that continues all the way down through Eau Claire will block that flow and prevent the inundation of much of the downtown.”
Another piece of flood infrastructure will be berms in Bowness, designed for one-in-20-year flood event.
“From the normal water levels you see now, to about the one-in-20, is about four metres of water level rise — 12, 13, 14 feet. To the 100 is only about another metre. So when we’re talking about the one-in-20, we’re generally talking about the level that is about one metre less than the one-in-100 (year flood event).”
Part of the problem inland, like in the Beltline, came from poor drainage — which we also see during thunderstorms in July and August.
“So the city does have something called a community drainage improvement program, that’s looking at going back through particularly parts of the city designed years ago — 1910, 1930 — where we didn’t have the information, the technology and the techniques we have today.
The goal will be to retrofit those areas with $300 million of new, green technology over the next decade that will help in both situations.