Tangaroa Restoration

These upgrades will be the backbone of the stormwater network that the catchment currently lacks, to deal with existing flooding issues.

The pipe along North Street that conveys the water to the Waitara River is undersized, and will be upgraded to convey the flows from a one in 100 year rainfall event (1% AEP with climate change allowance). The inlet and outlet of that pipe will also be upgraded.

A flood diversion structure will be created at the top of North Street to ensure that only high flows during significant rainfall get into the pipeline, while the normal flow will be maintained within the stream. This will reinstate the Tangaroa’s original connection with the Waitara River.

An additional section of pipe will connect the North Street diversion structure with Princess Street, along Richmond Street. This will allow an outlet for future improvements in the Princess Street stormwater network, although these are not part of the Tangaroa project.

This part of the works will recognise and provide for sites of cultural significance, improve water quality and habitat biodiversity, and enhance the mauri (life force/essence) to an awa of cultural significance. Restoration works will include:

• Riparian restoration of stream, wetland, and marsh habitats. Existing sections of the stream will be enhanced and some sections that were ‘lost’ due to the piping of the stream will be reinstated to their original state.
• Opening up the stream to daylight, and reducing barriers to fish movement.
• Creation of urban amenity, with opportunity for the community to reconnect with the awa.

Tangaroa was the name given to a channel near the Waitara River mouth and served as a tauranga waka (mooring site) for waka arriving at Manukorihi Pā, a 12-acre fortified complex located on a headland bounded by the Waitara River and overlooking the river mouth.

Tangaroa is a name also given to a freshwater stream that emerged from a puna (spring) at the south-eastern point of Manukorihi Pā and flowed in a north-westerly arc down the western headlands to Tangaroa harbour.

The Tangaroa Stream formed a natural boundary for Manukorihi Pā and was crucial to the safe and favourable living conditions of many generations. The puna and upper course was a site for ritual activity.

Tangaroa supported an ecosystem of indigenous flora and fauna. It also sustained the abundant wetlands at Manukorihi Pā where harakeke and raupo were grown and harvested for a wide variety of uses, and was home to numerous fish and insect species and a feeding ground for birds – the name ‘Manukorihi’ referring to their morning chorus, ‘a place where birds sing’.

Tangaroa Stream irrigated the extensive cultivations on the sheltered alluvial terrace below Owae Marae, which stretched down to the canoe harbour and were capable of supporting large gatherings in times of peace and war. In times of war, Tangaroa contributed to the impregnable defence system of Manukorihi Pā. The stream and wetlands provided a natural obstacle in front of the palisade line connected by a chain of east-facing defence forts. Tangaroa was also the primary source of freshwater, used to raise fish stocks and process various foods.

In the 1820s, during the sustained war with Waikato Māori, Manukorihi Pā was depopulated with the Tangaroa wetlands serving as a repository for the famed whakairo produced at Wharekura Marae within the Manukorihi Pā complex.

Manukorihi rose again in the late 1840s as a centre of resistance against land sales to the British Crown. Our opposition led to the outbreak of war with the Crown between 1860/61, which resulted in wholesale land confiscation under the 1863 New Zealand Settlements Act.

In 1883, The West Coast Reserves Settlement Commission allocated the 25-acre Manukorihi Block, which enabled Manukorihi Hapu to resettle in Waitara. Designated as a ‘native reserve’ vested with the Public Trustee, the Manukorihi Block included the central section of the Tangaroa watercourse. The puna, upper section and lower section of the waterway lay outside the Crown Grant area and were converted to individual land titles for residential and rural purposes.

From 1883, the Tangaroa water system ceased to be regarded as a whole entity and was subjected to despoliation by adjoining landowners.

• From 1891 to the early 1900s, Tangaroa harbour was progressively backfilled with river silt to create flat land for cattle and sheep yards servicing the Waitara Freezing Works.
• From the entry to Manukorihi Pā, Tangaroa Stream was diverted several times, draining into the Waitara River at different points. The spring water was commercialised by both a brewery and cordial factory in the late nineteenth and early twentieth centuries.
• By the mid-twentieth century, the tauranga waka was completely drained and filled. From the entry to Manukorihi Pā, Tangaroa Stream was split in two; one course ran down an open drain along North Street to the Waitara River, and the other was diverted to run under North Street, down to and around the newly created Pennington Park. 
• In 1998, the North Street open drain was made redundant and a new pipe was installed beneath the road, which is still in use today.
• The original course of the lower Tangaroa along Mouatt Street was filled and developed for housing.