Catchments in the Murray–Darling Basin

The Murray–Darling Basin is one interconnected system of rivers made up of 22 different catchments.

A catchment is an area of land, usually surrounded by hills or mountains, where water naturally collects. Gravity causes all rain, melting snow and other water in the catchment to run downhill where it flows into creeks, rivers, lakes or oceans.

Some water also seeps below ground where it settles in the soil or in the space between rocks. This is called groundwater.

Catchment boundaries are based on where rivers run and where the water falls. Each catchment has its own rules for water use.

This is because no two catchments in the Basin are the same. Each catchment is a different size and has a varied climate, a different landscape, a diverse environment and different communities and industries that use water in different ways.

Some catchments receive more rainfall than others. For instance, on average, more rain falls in the southern Basin than in the northern Basin. Some catchments are quite flat and water doesn’t naturally collect in those areas. Others have more hills or mountain ranges, which create natural valleys and lakes where water can be stored when it flows downhill.

The map below shows the 22 catchments.