The land next to a lake, river or stream where data has revealed that flooding is anticipated is called a floodplain. This area is usually defined through a study and mapping that accounts for weather, topography and soil types. The study determines how high the water will rise during a major storm and/or spring melt.
In the Cataraqui Region, as with the rest of southeastern Ontario, we plan for the 1:100 year (1 in 100 year) flood. This means that a flood has a one per cent chance of happening in any year. We often refer to the 1:100 year flood as the regulatory flood because this is what is used in our regulations and planning policies.
Cataraqui Conservation protects people and property from this flood by making sure that all buildings and structures are located outside of the floodplain and that the size of the floodplain is not reduced by filling. If fill is placed in the floodplain, the water that used to flow into that area during flood conditions moves into an area that did not previously flood. This could result in personal injury and property loss.
On Lake Ontario and the St. Lawrence River we also need to
account for flooding that is caused by wave action. This additional factor is called wave uprush.