A dredge.
Boats that are used to clear mud and silt from the river bed are called dredgers- those that are used to clear ice from frozen rivers are ice-breakers.
The bottom of the river is called the river bed.
The river bed.
the bottom of the river is called a bed
a flood!
bed
Normally there is a pool there, that is known as a plunge pool.
It is called a flat.
The bottom of a river is called the river bed.
I doont know man
Its name refers to the darkness of the river bed that has been lined with thick layers of decomposing vegetation.
dredging?