When you hear of flooding, many different images can come to mind.
The image below tells you more about the types of flooding. Each type of flooding is described below in an accessible format.
Riverine flooding occurs when water courses, like streams and rivers, have very high water levels and are overflowing into their floodplains due to heavy rainfall or spring snow melt. This can cause damage to areas nearby and can be particularly harmful when critical access routes are blocked. Learn more about seasonal flooding from the Toronto and Region Conservation Authority Fact Sheet.
Flooding doesn’t just happen near rivers and lakes. Stormwater runoff happens in our neighborhoods when there is more water than our drainage systems can handle and nowhere for it to go.
Flooding from rivers can also be caused or made worse by ice breaks and jams. These often occur in the spring time, causing rivers to back up and flood upstream. Learn more about ice jams from the Toronto and Region Conservation Authority Fact Sheet.
Residents that live close to shorelines like Lake Ontario may experience flooding due to storm surges, waves, and higher than normal lake levels.
Heavy rainfall can cause underground water levels to rise above ground level (1) and travel overland (2).
Different surfaces can absorb and infiltrate runoff. Impervious surfaces (1), like concrete and asphalt, cannot absorb water as well as natural surfaces (2) like wetlands, forests and meadows. This puts more pressure on drainage systems and impacts water quality.
