UNPREDICTABLE FLOODING IN THE GRAND RIVER WATERSHED

Yesterday's Waterloo Region Record carried this story "Flooding in local watershed becoming more unpredictable". The article is essentially suggesting that climate change has altered the timing of usual spring runoff flooding into a year round proposition. "...sudden thaws in winter, heavy runoff in spring, severe thunderstorms in summer and tropical storms in the fall,..." . While accurate about increased risks and flooding in the Grand River watershed nevertheless this article has missed a major point . One hundred years ago we did not have massive areas of Waterloo Region covered with concrete and asphalt. Think about all the sewers and manholes you see in our towns and cities. Instead of that water percolating slowly into the ground and eventually slowly discharging into surface bodies such as creeks and rivers via groundwater; instead the water flows directly by pipe to the nearest surface water body. Similarily if you live in the country watch the edges of fields and the ditches along them after a rainfall. It is absolutely amazing how many fields are tiled for the purpose of rapidly draining the soil and discharging it to ditches leading into creeks and rivers. My assumption is that tiled fields can be worked much earlier in the spring if they aren't a muddy mess . Obviously later in the summer in the middle of a drought the fields will also become arid much more quickly.

I have two predictions. Eventually cities and regions, perhaps in twenty years, maybe longer, will start to remove old asphalt and concrete from inner city abandoned areas in order to promote percolation of water into the subsurface. Secondly as our weather becomes drier watch farmers start to remove tiles from their fields in order to hold more rainwater and snowmelt on them.