catchment basin

It therefore belongs to the catchment basin of the Sutlej and not to the Indus, and the Tseti-la is a pass of secondary order.

Of the whole rainfall on the catchment basin, a part only finds its way to the stream.

The catchment basin is surrounded by a ridge or watershed line, continuous except at the point where the river finds an outlet.

The site is one of the most advantageous known for the creation of a flood-catchment basin.