This section presents an overview of New Zealand rivers, natural river processes and functioning, Māori and societal values, indigenous freshwater biodiversity, public perceptions and some of the use pressures. The protection of rivers is discussed in sections 3 to 6.
Rivers are inherently difficult to manage, owing to their dynamic character, length, size of catchment area, and diversity of values, as well as the many interest groups and agencies associated with land, water and fisheries management. Some parts of rivers or specific values (riverbeds, land adjoining rivers, wildlife, fish) may be protected through statute, while other aspects of the same river, such as flows, are not.
The 2005 review of the New Zealand Biodiversity Strategy noted a “serious decline” in the quality of many freshwater systems. This decline is adversely affecting biodiversity values and the full range of services that can be derived from rivers.
Despite a general reduction in point-source discharges from sewage and industry over recent decades, water quality in major rivers has declined since 1989. Increasing agricultural intensification and diffuse (non-point) discharges and nutrients associated with increased stocking rates and fertiliser use are the main contributors to this decline.
National allocation of fresh water almost doubled in the decade between 2000 and 2010, predominantly for increased irrigation.