100 Year Storm

I was watching the Weather Channel the other day (you can see how busy I am) and saw the report of a place in Ohio getting 12 inches of rain within a 24 hour period. That is about 30 cm as we measure things north of the border. I remember a couple of summers ago when North Bay got about 5 cm of rain in less than two hours and how it caused flooding because the storm sewers could not handle that sudden downpour. The weather person – a guy in a suit who knew all about isobars and fronts – said a high pressure just north of the Great Lakes had pulled all this moisture up from the Gulf; then a low pressure system sitting off the East coast had rushed ashore bringing moisture from the Atlantic. Maybe I got the highs and lows mixed up, anyway the two systems were battling it out over Ohio. I was still trying to figure it out when they went to a commercial for Lakota and how the pills would stop that aching I get in my knee every time the weather changes.

Our engineers have reckoned that about once in every 100 years we will get an unusual amount of rain, wind, snow or whatever mixture the heavens send us. So the prudent rule of thumb has been to design and build our infrastructure accordingly. That is, do not over-design systems for that one chance of a storm of epic proportions. Hence the overflow of the system when we got that cloud burst a few summers ago. The cost of cleaning up was less than the cost of over-building the infrastructure. Unless you were an engineer whose basement was flooded and whose spouse has never let you forget it, then the costs might be equal.

I am one of those few people who think maybe the climate is changing. When the US has more tornadoes in January than they normally get all spring, and when they had no hurricanes of note last year, something is amiss. When parts of Florida, where it used to rain every time we took a vacation down there, are in drought and Texas has more snow than they have seen in years, something is happening to our weather. Forget about all the talk about the polar bears because we will study and argue that long after the bears have grown brown hides and moved south. At least that is what you can tell your grandchildren. Blame it on evolution, if you want.

But it is those heavy downpours which worry me. Ohio is not that far from where we live, as the crow flies or the winds blow. Say that 30 cm of rain lost some of its punch before it hit Ontario and only dumped 15 cm of rain in 24 hours. I would wager that the engineers would all be saying it was just a 100 year storm and chances of it happening again, are very slim. The trouble is, it was raining again in Ohio as the Weather Channel showed us pictures of people in power boats cruising down Main Street – and they were not trolling for catfish!

Places that get heavy rainfalls usually put their drainage systems above ground, using dikes, spillways and levees to handle the rain. We have put our drainage systems underground where the capacity or volume is limited by the pipes. We have to contend with frost in our area and that may complicate the summer water-handling systems, but I am starting to wonder if we should not be recalculating just how often that 100 year storm may hit us.

Old timers, and my wife says I am sounding more like one every day, will tell you of storms that they remember as a kid and using that anecdotal information, 100 year storms are more frequent than the slide-rulers would have us believe. I remember Hurricane Hazel and we surely got several inches of rain from that storm (it was so long ago we were still measuring in inches). Creeks flooded, beaver dams broke, roads washed away and newspaper reporters had a heyday.

I also remember a March snow storm that created drifts of snow which were higher than the telephone poles between Hogan’s farm and Powassan. People had their Kodak cameras out as families posed on the snowdrifts, their cars peeping up from the tunnel the road crews had cut through the drifts. Mind you, the telephone poles were only about 20 feet tall back then. Of course, those events were nigh onto sixty years ago and not much has happened since then. Those cloud bursts we had last summer were an anomaly. A few junior tornadoes have found their way north in summer. The weather suits called them micro-bursts. Most of the snow now falls on Toronto where they love it, not on Jack Pine Hill where we need it. The last time it was so cold here that the lawyers had to put their hands in their own pockets was at least ten years ago, so maybe things are not as abnormal as the Weather Channel folks tell us.

If we can keep planting those carbon-credit trees maybe all this talk about the weather patterns changing and global warming will go away. The ocean currents will get back into a pattern that matches the 100 year storm theory and all will be well. The engineers designing the Mini-Chunnel from Memorial Drive to Oak Street can install 100 year drainage systems so the little train doesn’t flounder. In the meantime, if you are planning on building or buying a house, my advice is to stick to the higher ground. You never know when the next 100 year storm will hit.