How Fast Is Waterfall (Niagara)?

Water at Niagara Falls hits the bottom at 40 km/h. Roughly 168,000 m³ pour over the edge every minute — enough to fill an Olympic pool every second. The falls erode their rim about 30 cm per year as the water grinds away the underlying rock.

Niagara Falls erodes its own rim by 30 cm every year — slowly migrating upstream over time.

• Olympic pool over the edge every second
• Erodes 30 cm per year