Flooding along southern Ontario's rivers and streams is a normal event. Most floods occur in Spring, when the snow melts and precipitation tends to fall as rain. However, floods also happen in winter from time-to-time. Winter rains on frozen ground will often produce floods because the soil can't absorb as much water as it can when it's unfrozen.

In January, 2020, a heavy rainfall event near Guelph, Ontario, led to flooding along the Speed River. Fortunately, there are still large forested areas along the river that give the river a place to go when it floods. The ecosystem in this area is well-adapted to being underwater at times.

The January, 2020 flood temporarily turned this forest into a frozen swamp. Once the river carried away most of the water from the heavy rain, the forest slowly released the water back into the river.