Flooding ABC's

Gray Merriam | Mar 07, 2018

Lanark County recently brought in an expert on how to fight flooding with organized forces of trained volunteers. Technical tricks for fighting the floodwaters once they have threatened your home.

That is too late. We need to understand that floodwaters are rain and snowmelt that has run off the land too quickly. Flooding happens because the water was not kept on the land long enough.

To fight the increasingly common severe storms and unpredictable melting, we need to understand that floodwaters come from the whole area that drains into a river or creek. We call that area the watershed and the conditions on the watershed control what happens downstream. The condition of the watershed is the root cause of the flooding of your home.

If we completely cleared and paved the watershed, meltwater or rain from extreme storms would run off immediately and a great peak of flooding would engulf your house and our roads and wash out our bridges.

If the watershed was completely natural – clothed by forests and wetlands – the meltwater and the rainfall would be held back long enough that a lot of it would soak into the ground and the rest would take some days to flow down the river or creek. There would be a much smaller peak flow. The flood would not be so damaging or maybe would not happen.

The notion that we can fight floods caused by our changing weather pattern by sand bagging and adjusting logs in dams and other similar 'engineering' is a false hope. We and our conservation authorities must adapt to changing weather patterns by managing the vegetation and the natural habitats of our watersheds with the objective of holding the water on the land longer and letting the runoff happen more slowly. Germany is not the place to look for lessons on how to mange the landscape to prevent floods. Look upstream Lanark!