Why are some new roads inundated during a flood?
Many factors are considered when designing new roads, including potential regional flooding. Roads may be designed to allow floodwaters to continue to flow out of the river system into the ocean rather than temporarily holding them back. In many instances residential roads may be designed to a height above the one in 100 ARI flood event, others to one in 50 ARI or one in 20 ARI, to ensure evacuation routes remain passable during a regional flood event.
