river basin
basin **
watershed *
drainage basin
catchment area
catchment basin
drainage area

Later, the protective role of the river basin gave way to economic needs.

The river basin has a population of 5.4 million inhabitants.

In this way, the king gained control of the river basin.

Thus a large number of people along the river basin engage in fishing as well.

This makes it the largest single river basin entirely in the state.

It is one of four such dams in the river basin.

The area of the river basin is 3.5 square kilometers.

The river basin covers about 27% of the state's territory.

It is found in the major river basins of Brazil.

Several major river basins lie in part, or entirely, within Texas.