Kaipara Harbour (South)

The Kaipara Harbour is a very large, shallow, drowned valley estuary system on the west coast. The harbour comprises two major basins, with only the southern basin lying within the Auckland region. Several large rivers drain into the southern Kaipara, including the Hoteo, Kaipara and Kaukapakapa Rivers. Large areas of intertidal sandflats support diverse benthic communities, and areas of vegetation include mangroves, coastal shrubland, saltmarsh, and expansive seagrass meadows.

The catchment is dominated by rural land uses with pockets of urban areas. Although mud content is low at most monitoring sites, there have been increases over the last ten years especially in the south of the harbour.

The harbour is incredibly dynamic with regularly shifting sandbanks and channels. Large tidal movements are the dominant hydrodynamic process in the Kaipara. Approximately half of the harbour is exposed each low tide revealing rich benthic communities which provide important roosting and foraging areas for many endemic and migratory shore birds. The habitats within the harbour are important nurseries for fish species such as snapper, supporting populations that extend far beyond the harbour.

Auckland Council began monitoring the southern harbour in 2009 to increase knowledge of the benthic macrofaunal communities and how they changed over time. Monitoring was also intended to increase understanding around the effects of historic and current land-based activities on the ecological health of the harbour.

Estuary summary

What makes my estuary unique?

Explore the characteristics of this estuary

Overview

Estuary characteristics

Significant features
- Largest estuary in the country (and the southern hemisphere!)
- Habitats in the harbour provide nurseries for west coast snapper
- Manukapua Island and Okahukura Sequence biodiversity focus area
- Identified as an 'Important Bird Area'
- Significant Ecological Areas identified within the estuary as defined in the Auckland Unitary Plan

Total area
31,900 hectares

Total shoreline length
~320 km

Key rivers
- Kaipara River
- Hoteo River
- Makarau River
- Kaukapakapa River
- Araparera River

Highlighted reports

These links are from your regional councils and unitary authorities and provide additional information about this estuary

Auckland Council's 2020 SOE reporting Kaipara Harbour 2019 Marine Pest Survey

Related factsheets

For more details on particular topics see these factsheets

Understanding estuaries Estuary types

Department of Conservation

Want to connect with restoration groups or explore your local estuary? You can find more information on the DOC’s interactive maps.

Restoring estuaries map Experiencing estuaries map

What's happening upstream?

See results from monitored river quality sites influencing this estuary

River quality

What's happening upstream?

The physical characteristics and health of estuaries are influenced by the rivers and streams flowing into them. For instance, when it rains the mud and contaminants generated on land can be washed into rivers and eventually flow into the estuary. The health of our rivers and streams can therefore be very important for Estuary Health, and understanding the upstream pressures can help with interpreting estuary monitoring data.

Monitoring is undertaken for a range of river health indicators (e.g., water quality and ecology) in many catchments across the region. Where there are monitored river catchments that influence this estuary, these are shown below. You can click through to view monitoring results from these River Quality sites to see current state and how health has changed over time.

Hoteo River

1 site

Omaumau River

1 site

Makarau River

1 site

Kaukapakapa River

2 sites

Kaipara River

2 sites

What surrounds my estuary?

See land cover information from monitored catchments that surround this estuary

Land cover

What surrounds my estuary?

The physical characteristics and health of estuaries are influenced by local geography and the way we use our land. This is because estuaries are the receiving environments for many of our land use activities. Land cover information can be used as an indicator of land use, therefore knowing the surrounding land cover can help us understand which pressures might be affecting Estuary Health.

Where there is land cover information available for nearby catchments, these are listed below. These figures show the types of vegetation and built or natural features that surround the estuary margins and the rivers that flow into this estuary. You can click through to the Land Cover topic to see these land cover classes broken down into further detail, and view changes over time.

Hoteo River

Omaumau River

Makarau River

Kaukapakapa River

Kaipara River

What do the Broad Land Cover Classes mean?

Land cover information on LAWA is grouped into land cover classes at two levels of detail – broad and medium. For this overview we are showing the six broad-level classes for the catchment.

Forest

Inclusive of; indigenous and exotic forest.
Scrub / shrubland

Inclusive of; indigenous and exotic scrub / shrubland.
Grassland / other herbaceous vegetation

Inclusive of; tussock and exotic grassland and other herbaceous vegetation.
Cropland

Inclusive of; cropping / horticulture.
Urban / bare / lightly-vegetated surfaces

Inclusive of; natural bare/lightly-vegetated and artificial bare surfaces, and urban area
Water bodies