Tidal inundation is when low-lying coastal and estuary areas flood during high tides, even under normal weather conditions. It can cause water to backflow into urban drainage systems, increasing flood risks.

Coastal inundation is temporary flooding caused by storm surges that push ocean water higher than normal. This can lead to water overtopping dunes and seawalls, and flooding low-lying land, affecting homes, roads, and natural habitats.

Both types of inundation are expected to become more frequent and widespread due to climate change and rising sea levels.