Catchment Studies

A Catchment or watershed is the area of land from which all rainfall and streams flows out into a river, a lake or the sea. The catchment of large rivers, such as the Wairau River, can be divided into smaller sub-catchments, which usually represent the tributaries.

State of the Environment monitoring is generally carried out at the bottom of catchments and sub-catchments. From a management point of view, a decline in water quality at the bottom of the catchment can be reflective of a degradation of water quality in the catchment as a whole.

Where State of the Environment monitoring has shown that water quality is degraded, catchment studies are carried out. These studies provide insight into the causes of poor water quality. Using the information from catchment studies council can work with land owners to address problems and improve water quality.