Waimea Inlet

This page describes the Waimea Inlet and links to further information about its management and ecology.

The Waimea Inlet is the largest enclosed estuary in the South Island. It is 3,455 ha in area, with an internal coastline of 65 km. Episodes of heavy sedimentation occurred in the 1960s and 70s affecting some of the more enclosed parts of the estuary.

Approximately 170 hectares of intertidal habitat has been lost to reclamation, most of which occurred prior to 1980. During periods of high rainfall, elevated levels of disease-causing organisms can be flushed into the estuary. The historic effect of toxins from various industries and landfills is localised e.g. the Richmond industrial area and the now-remediated Fruitgrowers Chemical Co. site at Mapua.

There are ten islands in the inlet, with Rabbit Island forming an outer barrier that influences river and tide flows and sediment distribution. The Waimea River flows out to the two estuary mouths each end of Rabbit Island. It is shallow and well-flushed. The inlet is a large open space beside fast-growing urban centres. 

The inlet is of international significance for migratory bird species and is of national significance for other endangered or threatened species.  These include birds such as bar-tailed godwit, white heron, royal spoonbill, little egret, Australasian bittern, and banded rail, and plants such as coastal peppercress and grey salt bush.


Discharges to the Waimea Estuary from Industrial Sites

Estuarine monitoring of potential environmental effects from the now-remediated former Fruitgrowers Chemical Company site in Mapua has been ongoing since 1999 and more intensively since 2009. Such monitoring included sediment and biota (particularly cockles and snails) analysis at sites near the old FCC site, and at two reference sites.

The reports on the sedimant and biota monitoring are available:

Further Information