Category Archives: Engineering

The River Speaks

The River Speaks
The project was installed in the historic homestead of Tupare, which is situated on the Waiwhakaiho River

The River Speaks connects live river data from the Waiwhakaiho River to our project website, where the data controls the audio heard. The audio is one part of an installation consisting of a small assemblage located in between two video sources. The audio, video and installation all are reference points to rivers and flow.

The project is a collaborative work by Ian Clothier, Andrew Hornblow and Nina Czegledy. It was created for Sharing the Waiwhakaiho and was based on the live data from the Waiwhakaiho River.

The River Speaks data
The above image shows the actual river data graphed on February 8th 2015 – the stepped appearance is due to data coming into the project every thirty minutes – this is the time interval the Regional Council collects its river data

Some of the deeper connotations of associations with the river were explored. Wai, which means water or flow, is placed very highly according to eminent Maori activist and proponent of Maori language Dr Te Huirangi Waikerepuru CNZM. An animated chart describing layers of a Polynesian universe and written by Dr Waikerepuru, is one source of video. Some of the audio files played by the project website, are audio of Dr Waikerepuru talking about wai and the Waiwhakaiho River, from The Wasteland by Indian video artist Sharmila Samant.

Jo Tito photo of wai
The patterns of flow are caught by Jo Tito revealing both Maori and science based understanding

The second video source is a video by Jo Tito of sea water shot in the tidal zone of a local beach. Tito was very interested at the time she shot the video, in connections between Maori knowledge and Western science. It is possible to see in the sweeping lines of flow she captured, both the repeating patterns of Maori art and design, and the structures of flow as it might be studied by Western science.

Nestled between these two is an assemblage – a container in which are placed a kawakawa (a small native tree) tree root which has a feather attached. These two are respectively symbolic of the dendritic drainage patterns of which Taranaki is an exemplar – the Waiwhakaiho River being one catchment; and a reference to flow and turbulence in the air for which the feather of a bird is uniquely engineered. The feather is that of a native kereru, a large wood pigeon. These two sit upon an antique Chinese bowl, a reference to some of the items located in the rooms which housed the installation.

The audio component of the project sweeps in with audio from diverse sources, all indigenous. The aim of connecting to the environment by using data sensors and interconnecting to audio, was to open a dialogue with indigenous peoples many of whom hold water or flow in very high regard.

Thanks to Andrew Hornblow who makes custom data sensors, Julian Priest and Adrian Soundy who authored the web components. A very special thank you to the contributors of the audio and to Nina Czegledy who brought two new voices to the project – artist Kura Puke of the local Ngati Tawhirikura hapu, video producer/director and Nanavut Inuit Stacey Aglok MacDonald, who joined Dineh/Navajo flautist Andrew Thomas, and Darren Robert Terama Ward (Te Whanau a Apanui, Te Aitanga a Mahaaki) who makes his own traditional Maori instruments. I’d also like to thank Dr Te Huirangi Waikerepuru for his words, wisdom and forethought, and Clare Mewse of the Regional Council, for the use of Tupare House for the installation.

Taranaki – hydro power pioneer

The original Mangorei power station much of which is still in use today. Image sourced from: Puke Ariki Learning and Research archives.
The original Mangorei power station much of which is still in use today. Image sourced from: Puke Ariki Learning and Research archives.

New Zealand has an early history of drawing on hydro power to produce electricity. The Taranaki district in particular, has been a pioneer in the use of hydro-powered electricity, establishing 7 of New Zealand’s 14 public sources of electricity in the early times.

Taranaki takes the prize as the most electrically-minded province during the early years of power generation in New Zealand. Neil Rennie writing in 1989 from Power to the People [see note 1 below].

Taranaki’s early sources of electricity stemmed from hydroelectric schemes that drew from the water supplies and many streams that surround Mt Taranaki/Egmont. Demand for a public source of electricity began to increase as New Plymouth’s urban population grew. Additionally, local farmers, who were originally self reliant on their self generated sources of electricity, began to use more industrialised technologies. These technologies required a steady supply of electricity. Consequently the new farming methods provided a practical and economic justification for the establishment public power schemes.

In the beginning of the 20th century Mangorei Power station was established on the Waiwhakaiho River near Burgess Park. In its early stages Mangorei power station was constructed to be a combined water and electricity supply. It provided power to 41 homes as well as New Plymouth’s street lights in urban areas. During this era of its development the Mangorei power station required a mere 1200-metre water supply that was then piped directly from the Waiwhakaiho River to its neighbouring generating station.

In the summer time power was often unreliable as the water levels along the Waiwhakaiho would run low. In response to this dilemma local government commissioned the construction of a dam along the Māngamāhoe Stream in 1914. Consequently a new intake was also constructed further up the Waiwhakaiho River and a 420-metre open water race led to the dam [2]. Unfortunately this extension on the Mangorei Power Station was not as efficient as its original design; the Māngamāhoe Stream intake frequently became blocked by stones, boulders and other debris which required removal by hand. The development of this system however has left a historical mark in Taranaki as the piles of boulders that were removed by local residents by hand from the stream, have remained alongside the intake.

In 1971 the original low-head dam that accompanied this structure was rebuilt and replaced by another low-head dam several meters downstream. The remains of the first dam and its intake to the power station may still be seen a few metres up from the second dam [3].

From its humble beginnings in 1906 the Mangorei Power Station continues to be one of New Zealand’s oldest operating power stations. Although it has much evolved from its original from its evidence of its earlier structures can still be traced as it remains a central component of Taranaki’s and New Zealand’s industrial heritage [4].

[1]. Lambert, R. (n.d). The Alchemy of the Engineer: Taranaki Hydro-electricity, paragraph 1. Retrieved from:

[2]. As above, paragraph 8.

[3]. As above, paragraph 8.

[4]. As above.

The heritage of bridges at Te Rewa Rewa

Te Rewa Rewa Cluster refers to the mixtures of heritage located around the mouth of the Waiwhakaiho: it is the site of an important pah, the outlet of the Waiwhakaiho River to the sea and an important point in the much loved coastal walkway. Here the heritage of times past mixes with natural and human made waterways, fishing and recreation.

An aerial photograph of the current Te Rewa Rewa Bridge, the bridge provides an extension of the existing New Plymouth Coastal Walkway into the suburb of Bell Block by crossing the Rewarewa Reserve, which is sacred land of the Ngati Tawhirikura tribe. The bridge’s distinct form resembles whale bone which symbolises the sacred relationship between the land, sea and wind for the local Ngati Tawhirikura tribe. Image source from: Heavy Engineering Research Association (HERA) New Zealand.
An aerial photograph of the current Te Rewa Rewa Bridge. The bridge provides an extension of the existing New Plymouth Coastal Walkway into the suburb of Bell Block by crossing the Rewarewa Reserve, which is sacred land of the Ngati Tawhirikura tribe. The bridge’s distinct form resembles whale bone which symbolises the sacred relationship between the land, sea and wind for the local Ngati Tawhirikura. Image source from: Heavy Engineering Research Association (HERA) New Zealand.

New Plymouth as a region has a long and distinct social history of bridges, particularly in relation to the Waiwhakaiho River. This history stems from early settler years and follows through to today, whereby the current Te Rewa Rewa Bridge continues to be well loved by many New Plymouth residents and remains a popular pedestrian bridge enjoyed by many on the weekends.

The concept of a bridge that crossed the mouth of the Waiwhakaiho River was first suggested in 1842 by Frederic Alonzo Carrington who was one of New Plymouth’s city fathers.

Fig 2
Father of New Plymouth and the Chief Surveyor for the Plymouth Company: Frederic Alonzo Carrington. Image sourced from: Puke Ariki, Learning and Research Archives.

By 4 November Carrington had produced a map of the future New Plymouth. It included a suspension bridge that spanned across the mouth of the Waiwhakaiho River. However it is important to note that Carrington’s site was criticised by many residents for its lack of a harbour, additionally Maori disputed possession over their lands.

Originally a suspension bridge was built using chains and puketea timber. However over time the chains began to erode through the puketea timber supports and eventually The Bridge collapsed into the river and the remains of it were washed away. Other wooden suspension bridges were built to replace this bridge however they too slowly deteriorated over time and failed to with stand the force of the Waiwhakaiho River.

Years passed before anyone attempted to rebuild the bridge. During this period there were many fatalities as early settler communities struggled to cross the Waiwhakaiho River, particularly during winter when flooding occurred. Local government responded to this problem by commissioning the construction of a puri puri bridge in 1857.

This bridge was constructed on March 3, prior to the Maori land wars. Consequently during the land war battles of Taranaki in 1860 the army lost control of this bridge for a week, as Maori had seized control of Fitzroy. Taranaki Daily News reports:

“The commanding officer in New Plymouth, worried that the bridge had been burnt down, signalled volunteers from the Bell Block stockade to check the rumours. A small party of men rode into Fitzroy from Bell Block as far as the Mangaone hill and returned with the news the bridge was safe”(Taranaki Daily News, 2012).

Unfortunately in 1867 the puri puri bridge was badly damaged during a period of heavy flooding. During this time the use of concrete within engineering was a new and innovative concept. New Zealand began to commission the establishment of various concrete structures, many of which “were unique even in world terms” (Reed, Schoonees & Salmond, 2008, p. 12).

The New Plymouth district in particular pioneered several early concrete structures between 1850 and 1860 (Thornton, 1996). One such structure happens to be the refurbishment of the 1867 puri puri bridge. The remains of the 1867 bridge were rebuilt and reinforced by a ferro-concrete bridge.

“The structure comprised four arches, two of 10m span and two of 20m, with a 7m iron carriageway and two footways. The iron weighed 20kg a metre. More than 32 tonnes of steel were used in the construction (Taranaki Daily New, 2012).”

Here is a black and white etching of the former concrete bridge.

A black and white etching of the ferro-concrete bridge crossing the mouth of the Waiwhakaiho River.
A black and white etching of the ferro-concrete bridge crossing the mouth of the Waiwhakaiho River.

This bridge was opened in 1907 by Mr Brown, who was the chairman of the county council. Many of the local residents who had helped erect the old bridges were present as the concrete bridge was built.

To celebrate the construction of the new concrete bridge a parade which included members of the county council in bullock wagon drawn by two oxen, followed by local residents crossed the bridge. A public luncheon was then held along the Waiwakaiho River banks, followed later by a community ball at the Masonic Hotel (Taranaki Daily News, 2012).

A newspaper clipping from the Taranaki Herald published October 18th 1907 informing New Plymouth residents about the establishment of the new ferro-concrete bridge and the celebrations that followed. Image sourced from: Papers Past.