Te Awarua-o-Porirua Harbour is located 21 km north of Wellington City and comprises two inlets; Onepoto, which extends from Mana to the shoreline of Porirua City and Pāuatahanui, which stretches eastwards from the Paremata Bridge towards the Pāuatahanui Wildlife Reserve. The Harbour was originally named Pari-ā-Rua, which translates to “twin flowings of the tide”. Entrances to both inlets provide a calm and accessible area for recreational use, while the head of Pāuatahanui Inlet is home to a world-class wetland reserve that is being threatened by sea level rise.

This system is of great cultural importance to Ngāti Toa Rangātira who have kaitiakitanga (guardianship) over the area and historically used the Estuary as mahinga kai. This area is also of significant economic and ecological value with a catchment that includes 18,470 ha of rural farmland, lifestyle blocks, urban settlement, parkland, and rail and road corridors that present ongoing pressures on the estuarine ecosystem. The key issues facing this sensitive environment are excessive sedimentation rates, pollution, and ecological degradation.

Currently Greater Wellington (GW) monitor intertidal estuary sediment quality annually to understand the natural variation within the environment and the impacts of human activities. Other studies such as subtidal sediment and macrofaunal assessments, habitat mapping, and bathymetry surveys are undertaken every four years or when substantial shifts are recorded during sediment plate surveys. Current and historical data are presented on interactive maps within this web report to provide an indication of the health of the Harbour over time.

Our web report may be cited as: Greater Wellington (GW). 2022. Te Awarua-o-Porirua Harbour monitoring – Web report. Downloaded from https://www.gw.govt.nz/environment/environmental-data-and-information/water-monitoring/.

A PDF print-version of this report can be viewed and downloaded here.

Te Awarua-o-Porirua Harbour monitoring sites
The whole estuary is periodically monitored for changes in: salt marsh and seagrass cover, macroalgal density, substrate, and bathymetry. Hover over map circles to see indicators measured at each site. Note that sites and indicators vary across the sampling period.