During a flood event, breaking its banks means the water gets high enough that the river outgrows its traditional banks. This can result in erosion and the creation of entirely new flowpaths for a river.
The bank of a river or creek is the earth that lines the edges of a waterway, forming a barrier, or levee, to stop the water from flowing out of the river (except when it "breaks its banks" during a flood). The platypus digs a burrow that may extend up to 30 metres into this levee. The entrance of the burrow is above the waterline, not underwater. This is the platypus's home.
It is built on the banks of the Thames river.
The Amazon river carries more water than any other.
The sides are known as the river bank or river banks.
The part of a river that is underwater when the river overflows its banks is called the flood plain.
A foodplain is a flat or nearly flat land adjacent a stream or river that stretches from the banks of its channel to the base of the enclosing valley walls and experiences flooding during periods of high discharge.
I think you mean a 'ford'.
a time when the river water rises high and spills over the river banks
On the banks of river Ganga
Godavari River
banks
The Tungabhadra river