Rethinking Lifestyle

As I wrote this post, we were experiencing a massive thunderstorm, part of a system moving through the Province from north west to north east. It lasted a while on and off.

The rain was hitting the roof so hard it had overflowed the eavestroughs, and the wind was making the trees sway about, and so my thoughts turned to Houston and areas to the south of us, and I asked myself if Steinbach is at risk from an event like Hurricane Harvey?

Steinbach is situated in an area of low swampy ground. The poorer land in an area of good farmland. Water drains towards it from different directions, and before the city was built there, it would have been a natural reservoir for water, holding it, and letting it away slowly as the waters around it drained. As the city was built, large drainage channels were built to carry the water away quickly along highway 12, and newer housing areas are built with large ditches – such as those around the housing near the soccer pitches and Barkman Park.

But are they enough? What conditions could lead to flooding as was seen in Houston?

We get most of our precipitation in winter don’t we?

Well no actually, that’s not true. We do get a fair bit of snow, but much of it is air, not water. Most of the precipitation in this area comes from rainfall, and much of it during June and July according to the 30 year averages.

And we have experienced some extreme rainfall in the summer months. Remember July 2012 when heavy rains led to flooded streets and backed up drainage systems. Or August 2014, when more than 100mm rain fell in just one hour, flooding basements and streets in Niverville.

Rainfall events are increasing – as glaciers and arctic ice recede, there is more water in the oceans and atmosphere available as rain. Storm events become more unpredictable and more violent as a result.

In spring, we are prepared for flooding from snowmelt, clearing icedams, sand-bagging and so on. The water comes relatively slowly, and we can prepare for it. In the summer, the storms often happen suddenly. We might have a few days warning, but we are usually glad the garden will get some much needed water, and our minds do not turn to flood preparation.

Getting water away is the best approach isn’t it?

Systems that rely on water getting away quickly are very much dependent on what is happening downstream. If we have several days of heavy rain, or a massive amount in a short period of time, then the ditches will be full, and the run-off from the concreted areas in the city will have nowhere to go – this is when the flooding happens. This is what happened in Houston.

Getting water away quickly doesn’t deal with contaminants either. The run-off from Steinbach will include all kinds of chemicals and organic materials from all the different industries in and around the city, and it will likely include sewage from flooded systems. It reaches the drainage ditches in this contaminated state.

What are the options?

Cities around the world are addressing the run-off problem by ‘slowing the flow’. It’s a whole system approach. Medians are modified to drain to underground pipes, porous surfaces allow slow drainage from parking lots to storage areas, constructed wetlands store water and clean it before it is slowly released, and these features are designed and built into the landscape. In the Netherlands, where many larger cities are below sea level, they have a different and more holistic relationship with water – we could learn a lot from the dutch if we are willing to.