Flood?
a drainage basin is the geographical area draining into a river or reservoir. If it over flows, I think that is bad because it could cause a flood.
a time when the river water rises high and spills over the river banks
The strata over which a river flows.
The Zambezi River
Over flows
they have to much rain causing the river to rise over the river banks.
A spur in the River Tees is formed through the process of river erosion and meandering. As the river flows, it erodes the outer banks of bends due to faster water flow, while sediment accumulates on the inner banks where the flow is slower. This creates a protrusion or spur of land that juts out into the river. Over time, continued erosion and deposition shape the landscape, reinforcing the formation of the spur.
These are called meanders. Meanders are loop-like bends in the course of a river formed by erosion and deposition processes that occur as the river flows over the landscape, causing it to curve and twist. They are a common feature of mature rivers.
A waterfall.
It could become a waterfall. Or if it just flows over onto more land then it becomes a river, not a stream.
The Angara River leaves Lake Baikal at Port Baikal/Listvyanka from where it flows north and west until it runs into the Yenisey River north of Krasnoyarsk and flows into the Kara Sea.
The water flows over a water fall