Lake Waikaremoana
Encyclopedia
Lake Waikaremoana is located in Te Urewera National Park
Te Urewera National Park
Te Urewera National Park is one of fourteen national parks within New Zealand and is the largest of the four in the North Island. Covering an area of approximately 2,127 km², it is in the north east of the Hawke's Bay region of the North Island....

 in the North Island
North Island
The North Island is one of the two main islands of New Zealand, separated from the much less populous South Island by Cook Strait. The island is in area, making it the world's 14th-largest island...

 of New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

, 60 kilometres northwest of Wairoa
Wairoa
Wairoa is a town in New Zealand's North Island. It is the northernmost town in the Hawke's Bay region, and is located on the northern shore of Hawke Bay at the mouth of the Wairoa River and to the west of Mahia Peninsula...

 and 80 kilometres southwest of Gisborne
Gisborne, New Zealand
-Economy:The harbour was host to many ships in the past and had developed as a river port to provide a more secure location for shipping compared with the open roadstead of Poverty Bay which can be exposed to southerly swells. A meat works was sited beside the harbour and meat and wool was shipped...

. It covers an area of 54 km². From the Maori Waikaremoana translates as 'sea of rippling waters'

The lake lies in the heart of Tuhoe
Tuhoe
Ngāi Tūhoe , a Māori iwi of New Zealand, takes its name from an ancestral figure, Tūhoe-pōtiki. The word tūhoe literally means "steep" or "high noon" in the Māori language...

 country. The hamlet of Āniwaniwa and the Waikaremoana Motor Camp are located on the lakeshore, along SH38
New Zealand State Highway 38
State Highway 38 is one of New Zealand's State Highways on the North Island. It starts near Wai-O-Tapu at the intersection with SH 5 and it ends at Wairoa, where it connects to SH 2. It is the shortest connection from the Central North Island to the East Coast , but it is not often used as such...

 (from Wai-O-Tapu via Murupara
Murupara
Murupara is a town located in the North Island of New Zealand. The town is situated in an isolated part of the Bay of Plenty region between the Kaingaroa Forest and Te Urewera National Park, on the banks of the Rangitaiki River, 65 kilometres southeast of Rotorua, along SH38. Murupara is the...

 to Wairoa), which connects the lake to the central North Island (Rotorua) and Gisborne. There is a Department of Conservation
New Zealand Department of Conservation
The Department of Conservation , commonly known by its acronym, "DOC", is the state sector organisation which deals with the conservation of New Zealand’s natural and historic heritage...

 office at Aniwaniwa. Several walks start here, including a short stroll to Aniwaniwa Falls
Aniwaniwa Falls
The Aniwaniwa Falls, or Rainbow Falls, are a two-drop waterfall located at northeastern Lake Waikaremoana in New Zealand....

.

Lake Waikaremoana is a holiday destination by people who use the lake for fishing, tramping and other recreational activities. The Lake Waikaremoana Track
Lake Waikaremoana Great Walk
The Waikaremoana Great Walk is a 43 kilometre tramping track which follows the southern and western coast of Lake Waikaremoana in the North Island of New Zealand. Passing through several types of forest, and grassland, track often provides excellent views over the lake...

, one of New Zealand's "Great Walks"
New Zealand Great Walks
The New Zealand Great Walks are a set of popular tramping tracks. They are New Zealand's premier tracks, through areas of some of the best scenery in the country...

, is a three to four-day tramp which follows approximately half of the lake's circumference. The track can be walked independently, or as part of a guided group. There are huts dotted on the walk which require booking to use. Camping is permitted unless you are more than 500 metres from the track.

Numbers of visitors to the area are mitigated by the unsealed road that must be taken to reach it. The smaller Lake Waikareiti
Lake Waikareiti
Lake Waikareiti, also spelt Lake Waikare Iti, is located in Te Urewera National Park in the North Island of New Zealand. A number of hiking trails are found within the catchment basin of the lake....

 lies four kilometres to the northeast.

Geography and natural history

Waikaremoana is the North Island's deepest lake (256 m deep), its surface being an altitude of 600 metres above sea level. The lake has been created by a huge landslide dam
Landslide dam
A landslide dam, debris dam, or barrier lake is a natural damming of a river by some kind of mass wasting: landslide, debris flow, rock avalanche or volcano. If it is caused by earthquake, it may also be called a quake lake. Some landslide dams are as high as the largest existing artificial dam...

 about 250 metres high and is believed to be around 2,200 years old. Prior to the landslip being sealed, around 1950, much of the lake outflow flowed through the landslip rather than out an overflow at a low point in the slip.

Other geographical features include Panekiri Bluff and Puketukutuku Peninsula, which is the site of a kiwi
Kiwi
Kiwi are flightless birds endemic to New Zealand, in the genus Apteryx and family Apterygidae.At around the size of a domestic chicken, kiwi are by far the smallest living ratites and lay the largest egg in relation to their body size of any species of bird in the world...

 conservation programme. Surrounded as it is by mountains clad with native forest which has never been logged, it is regarded as the North Island's most attractive lake. Many native bird species scarce in most other parts of the North Island can be found in the area. A possum-hunting programme operates in the area to help protect the forest. There are numerous understory species within the forested area of the catchment basin, Crown Fern, Blechnum discolor
Blechnum discolor
Blechnum discolor is a species of fern in the family Blechnaceae. This species is endemic to New Zealand. As noted by C. Michael Hogan, this species is found in a number of forest communities in diverse locations within New Zealand, and is sometimes a dominant understory component.Spores are...

, being an example. Since at least the early 1900s lake bottom molluscs have been studied by Colenso
William Colenso
William Colenso was a Cornish Christian missionary to New Zealand, and also a printer, botanist, explorer and politician.-Life:Born in Penzance, Cornwall, he was the cousin of John William Colenso, Bishop of Natal...

 and others.

Hydroelectric power scheme

The Waikaremoana Hydroelectric Power Scheme appears to be the only example of a hydroelectric power station being built on a natural landslide dam. As early as 1930 the wisdom of building a hydroelectric scheme on, in and below a natural landslide were questioned.

Modifying the natural dam

The stability of the natural dam has been the subject of intense engineering review, both at the time of construction and subsequently. Construction of an outlet tunnel through the slip, which commenced in 1935, required extensive grouting around the control structures and throughout tunnel construction. Work was suspended ath the end of 1936 because Bob Semple
Bob Semple
Robert "Bob" Semple was a union leader and later Minister of Public Works for the first Labour Government of New Zealand....

, the newly elected Minister for Public Works, wanted the tunnelling project reconsidered for "risk, cost and value". A new tunnelling scheme was devised in 1941 based on what had been learned from initial exporatory tunnelling and work recommenced in 1943 and continued for about 5 years because of continual problems with dewatering the tunnels. After the tunnels and intake headworks had been completed the natural dam was sealed for leaks on the lake side by removing submerged timber, a task that took a year and then applying 40,000 cubic metres of crushed rock and clay-like pummice in 6 layers, then covering those layers with a top layer of larger rock and spalls to protect the material from wave action. This sealing reduced the natural flow by about 80%. The sealing of the lake was only done after tunnelling was completed otherise it would have caused the lake level to rise and make tunnelling more difficult. As it was, the lake level had to be lowered by temporary syphons to enable the construction of the headworks and make sealing of the natural dam easier.

Power stations

Although the Waikare River carries a flow of about 17 m³/s from Lake Waikaremoana, the head of water through the 3 power stations, Kaitawa, Piripura, and Tuai is around 450 metres, allowing the stations to potentially generate 124 megawatts all up. The 250m head of water for the Kaitawa station is the highest for a dam in New Zealand and among the highest in the world.

See also

  • Lake Waikaremoana Great Walk
    Lake Waikaremoana Great Walk
    The Waikaremoana Great Walk is a 43 kilometre tramping track which follows the southern and western coast of Lake Waikaremoana in the North Island of New Zealand. Passing through several types of forest, and grassland, track often provides excellent views over the lake...

  • Lakes of New Zealand
    Lakes of New Zealand
    There are 3,820 lakes in New Zealand with a surface area larger than one hectare. The lakes are of varying types and origins. Many of the lakes in the central North Island area are volcanic crater lakes, while the majority of the lakes near the Southern Alps were carved by glaciers...

  • List of lakes in New Zealand

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External links

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