When a river "crests," it means the river has reached its highest water level at a particular location during a flooding event before the water level begins to fall. This peak is the maximum height the river attains above a reference point, often called the datum point, which is a standard baseline used to measure water levels
. To visualize it, think of a large wave of water moving downstream; the crest is the top of that wave as it passes a specific point. After the crest passes, the water level will start to recede, although the river may still remain high for some time
. Understanding when a river crests is important for flood forecasting and safety, as it signals the peak of flooding risk and helps communities prepare for the subsequent decline in water levels
. In summary, "river cresting" means:
- The river has risen to its highest expected level at a given point during a flood.
- After cresting, the water level will begin to drop.
- It is measured relative to a datum point, not the riverbed.
- It is a key concept in hydrology and flood management
