Come health with high water: how flooding supports our wetland ecosystems
Come health with high water: how flooding supports our wetland ecosystems

Come health with high water: how flooding supports our wetland ecosystems

A couple of weeks ago, I climbed a grassy hill overlooking Athalmer to get a better view of the lake.

I was surprised to notice what normally appeared to be a dry patch of reeds and grass now rippling and glimmering in the sun.  I hadn’t realized it before when the water was low, but this was a tiny wetland!

Wetlands undergo a natural (and sometimes dramatic) cycle of wetting and drying on an annual basis. Seeing the high water levels this past week really got me thinking about the importance of flooding in our wetlands at this time of year, and about the array of ecological benefits this delivers to our ecosystems and urban communities.


Flow regulators

Wetlands control extreme water levels by storing water during wet periods and releasing it during dry periods, essentially acting as a giant ecological sponge. The larger the wetland, the greater storage potential it has to “attenuate”, or soak up, flood waters that might otherwise cause damage downstream.


Biodiversity boosters

Seasonal flooding restores and redistributes nutrients among our river and wetland ecosystems. Flooding also helps maintain more resilient plant and animal communities, and is important for reproduction and development timing in many wetland species. Flooding can also promote seed germination, resulting in plant growth that purifies the air and water, and provides food and habitat for thousands of insects, birds, fish, and wildlife.


Water quality managers

When fast-flowing river water hits a thicket of wetland vegetation, it slows down, spreads out, and deposits much of the fine sediment it carried with it from high mountain streams. Sediment deposition improves water quality by reducing turbidity, making it easier for fish to see and breathe, causing fewer pathogens to be suspended in the water, and reducing the amount of heavy metals and other contaminants travelling downstream.


Needless to say, when I climbed back down from that grassy hill, I had a renewed appreciation for this small wetland, and for the expansive wetlands situated at the north and south ends of Lake Windermere.  These wetlands are a large part of the reason why we continue to have good water quality in this area, despite the intensive development that has occurred over the years.

Although we may be tempted to complain about high water levels at our beaches, boat launches, and public parks this spring, let’s not be so quick to condemn this natural process because it brings great ecological benefit to the lakes and rivers we love so much.


Have a question about your lake or watershed? Reach out to us! Contact (250) 341-6898 or

Leave a Reply

Your email address will not be published. Required fields are marked *