Understanding floods can be overwhelming, with all the different terms used in various reports, studies, and data. As we witness an increase in natural hazards, it's becoming more and more important to grasp these terms and their implications for us.
The Terms Used To Define Floods
Floodway: The most dangerous part of the floodplain, where water is moving in the channel of a river or stream, and the surrounding areas required to carry the regional flood discharge.
Flood storage
An area where floodwater accumulates, which, if displaced, can cause a significant redistribution of floodwaters, increase in flood levels or frequency. These areas are often aligned with floodplains and characterized by deep and slow-moving floodwater. Flood storage helps regulate the flood peak.
Floodfringe The portion of the floodplain outside of the floodway that is covered by floodwater during a regional flood. This term is generally associated with standing water rather than flowing water, and local floodplain ordinance requirements apply.
Floodplain The area of land subject to inundation by floods up to and including the probable maximum flood event, including the floodway and floodfringe areas.
Flood planning area The area within which developments may be subject to flood-related development controls. It is calculated as the area lower than the Flood Planning Level.
Probable Maximum Flood (PMF) The largest flood that could potentially occur at a particular location, usually estimated from probable maximum precipitation. The PMF defines the maximum extent of flood-prone land, i.e., the floodplain.
In short, the 100-year flood and floodplain refer to the same area, which includes both the floodway and floodfringe.
Interested in learning more about floods? The Land Insight blog explains flood data in more detail. Could your property be impacted by floods? Our tailored Environmental Reports provide access to comprehensive environmental record data and information. Each report is tailored to support your environmental investigations. Who are Land Insight? Land Insight are leading environmental insights and risk information specialists. Land Insight is trusted by over 300 organisations to enable informed decisions when considering environmental and climate risks relating to property. Their latest technology allows you to go beyond data with deep insights. Access all-encompassing data on climate risks, flood and fire, erosion and pollution hazards in one centralised location.
Get in touch with the Land Insight team to find out more about our environmental risk data.