Lake Ōkāreka (also spelled Okareka, Ōkareka and just termed Ōkāreka) is one of four small lakes lying between Lake Rotorua and Lake Tarawera, in the Bay of Plenty Region of New Zealand's North Island. The others are Lake Rotokakahi (Green Lake), Lake Tikitapu (Blue Lake), and Lake Ōkataina. All lie within the Ōkataina Caldera, along its western edge.
| Lake Ōkāreka | |
|---|---|
| Lake Okareka | |
 Lake Ōkāreka | |
 | |
  Lake Ōkāreka | |
| Location | Rotorua Lakes, Bay of Plenty Region, North Island |
| Coordinates | 38°10′S 176°22′E / 38.167°S 176.367°E |
| Type | Crater Lake |
| Primary outflows | Waitangi Springs |
| Catchment area | 19.6 km2 (7.6 sq mi)[1]: 56 |
| Basin countries | New Zealand |
| Max. length | 2.8 km (1.7 mi)[2] |
| Max. width | 1.9 km (1.2 mi)[2] |
| Surface area | 3.3 km2 (1.3 sq mi)[1]: 55 |
| Average depth | 20.0 m (65.6 ft)[2] |
| Max. depth | 34 m (112 ft)[2] |
| Surface elevation | 353.6 m (1,160 ft)[1]: 24 |
| References | [1][2] |
Geography edit
The lake has a circumference of 9.7 km (6.0 mi) and with an autumn mean lake level of 353.6 m (1,160 ft),[1]: 24 lies about 60 m (200 ft) above Lake Tarawera. Its outlet flows underground for half a mile and forms the Waitangi waterfall. Lake Ōkāreka seems to be connected with Tarawera by underground channels.[3] About 562 L/s (19.8 cu ft/s) in all, flows from Lake Ōkareka's catchment into Lake Tarawera.[1]: 70 The lake's maximum height is now regulated to 353.9 m (1,161 ft) by adjusting a valve in the Waitangi Stream Drain.[1]: 19 [4]
Geology edit
The lake is closely related to the Ōkareka Embayment on the western margins of the Ōkataina Caldera. Likely formative and modifying eruptions were the Te Rere rhyolite eruption of 25,171 ± 964 years BP[5] and the Rotorua eruption of 15,635 ± 412 cal.yr BP.[5]: 15 The effusive rhyolite dome forming process's to the lake's south east after these events would have modified its drainage into Lake Tarawera.
History edit
This small and little-visited lake is surrounded by hills nearly everywhere, and is a heavy hunting area. It is quite near, but out of sight from the tourist motor route of Rotorua and Tarawera. A side road, Tarawera Road, gives access to it. During the late 19th century, settlers acquired some of the land around it, and built houses on Ōkāreka. Some of the frontage is still in private hands, but the greater part of the basin in which the lake lies has now become residential property.
Ōkāreka means "the lake of sweet food".[6] It was first described in print by Sir George Grey, who visited it on the course of his travels through Rotorua to Taupō in 1849-1850. The route from Ohinemutu to Tarawera was a track which skirted the shore of Ōkāreka and reached the large lake, near the mission station called Galilei. Grey's journal reads:
"We reached the beautiful lake of Okareka, just at a place where there is a spring of deliciously cool water, wherewith we all refreshed ourselves and then proceeded to cross the lake in canoes. The lake is really an extremely pretty sight, the shores being lofty and wooded, with the exception of a valley at each end, where the roads run. A peninsula, on which stands the pa called Taumaihi, juts out into the centre of the lake. The waters are beautifully clear, and very deep. There is no apparent outlet to this lake. Its vent consists of an underground stream, which is hidden for about half a mile, and then makes its appearance, looking like a fountain, gushing through a heap of rocks and square stones of a basaltic formation, whence it makes its way in a small stream to Tarawera, the level of which is about sixty feet lower than that of Okareka, and into which the water falls down a declivity of twenty feet, forming a beautiful cascade, surrounded and overshadowed by a clump of karaka and other evergreen trees."
Grey is also presumed to have introduced Dama Wallaby to the area around Ōkāreka, where they presently still pose a problem.[7]
The shores of Ōkāreka were a scene of Māori life. Cultivations along the lake were common, and Māori fished the waters for whitebait, koura crayfish and toitoi, which were common species in Lake Ōkāreka before Brown trout was introduced. In the 1860s, Alfred Domett visited Ōkāreka and Tarawera, following a similar path to the one that Grey took.
Known for its natural environment, this lake has an adjacent settlement of approximately 600 people. The lake is accessible from the tourist location of Rotorua. The forest nearby to Lake Ōkāreka extends to the western side of Lake Okataina and the Whakapoungakau Range.
Pollution edit
Lake Ōkāreka has reasonably clear, clean water and is used extensively for recreation such as boating, swimming and fishing. However, the quality of the water has been declining over recent years due to excess levels of nitrogen and phosphorus. These nutrients come from surrounding farmland, residential septic tanks and from the release of existing and accumulated nutrients from sediments on the lake bed.
The Lake Ōkāreka Catchment Management Plan was developed in 2004. This is a long-term plan to improve the water quality of the lake, through changes like sewage reticulation, in-lake chemical treatment and farm nutrient management. It has been calculated that the load nutrients needed to reach the target TLI of 3.0 are 2.5 tonnes per year of nitrogen and 0.08 tonnes per year of phosphorus.
The trophic level index (TLI) is an overall indication of lake health based on a number of different criteria, values represent a three-yearly average. Better quality sites have a lower TLI. The three-yearly average for Ōkāreka indicates little change over the last five years, being 3.3 in 2014.[1]: 5
Lake Okareka township edit
The township on the shores of Lake Ōkareka is described by Statistics New Zealand as a rural settlement, and covers 1.46 km2 (0.56 sq mi).[8] It had an estimated population of 530 as of June 2023,[9] with a population density of 363 people per km2. Lake Okareka township is part of the larger Kaingaroa-Whakarewarewa statistical area.[10]
| Year | Pop. | ±% p.a. |
|---|---|---|
| 2006 | 519 | — |
| 2013 | 537 | +0.49% |
| 2018 | 519 | −0.68% |
| Source: [11] | ||
The township had a population of 519 at the 2018 New Zealand census, a decrease of 18 people (−3.4%) since the 2013 census, and unchanged since the 2006 census. There were 183 households, comprising 255 males and 258 females, giving a sex ratio of 0.99 males per female, with 102 people (19.7%) aged under 15 years, 75 (14.5%) aged 15 to 29, 246 (47.4%) aged 30 to 64, and 87 (16.8%) aged 65 or older.
Ethnicities were 94.2% European/Pākehā, 10.4% Māori, 2.3% Pacific peoples, 1.7% Asian, and 1.2% other ethnicities. People may identify with more than one ethnicity.
Although some people chose not to answer the census's question about religious affiliation, 54.9% had no religion, 38.2% were Christian and 0.6% had other religions.
Of those at least 15 years old, 186 (44.6%) people had a bachelor's or higher degree, and 36 (8.6%) people had no formal qualifications. 126 people (30.2%) earned over $70,000 compared to 17.2% nationally. The employment status of those at least 15 was that 210 (50.4%) people were employed full-time, 75 (18.0%) were part-time, and 9 (2.2%) were unemployed.[11]
See also edit
References edit
- ^ a b c d e f g h White, P; Toews, M; Tschritter, C; Lovett, A (2016). "Nitrogen discharge from the groundwater system to lakes and streams in the greater Lake Tarawera catchment GNS Science Consultancy Report 20151108" (PDF). Retrieved 26 August 2023.
- ^ a b c d e Lowe, D.J.; Green, J.D. (1987). Viner, A.B. (ed.). Inland waters of New Zealand. Wellington: DSIR Science Information Publishing Centre. pp. 471–474. ISBN 0-477-06799-9.
- ^ Ferdinand von Hochstetter, Edward Sauter (2010). New Zealand: its physical geography, geology and natural history, Kessinger Publishing, p. 406. ISBN 1-167-02635-7
- ^ "Lake Ōkāreka Outlet – Guidelines for Operation of Structure" (PDF). Retrieved 29 August 2023.
- ^ a b Lowe, David; Ilanko, Tehnuka. "Pre-conference tephra data workshop – Hands-on session II: tephra excursion, Okareka Loop Road (29 January 2023)". Retrieved 21 March 2023.
- ^ "1000 Māori place names". New Zealand Ministry for Culture and Heritage. 6 August 2019.
- ^ "Mountain poison drop targets pest wallabies". NZ Herald. Retrieved 9 September 2021.
- ^ "ArcGIS Web Application". statsnz.maps.arcgis.com. Retrieved 10 January 2023.
- ^ "Subnational population estimates (RC, SA2), by age and sex, at 30 June 1996-2023 (2023 boundaries)". Statistics New Zealand. Retrieved 25 October 2023. (regional councils); "Subnational population estimates (TA, SA2), by age and sex, at 30 June 1996-2023 (2023 boundaries)". Statistics New Zealand. Retrieved 25 October 2023. (territorial authorities); "Subnational population estimates (urban rural), by age and sex, at 30 June 1996-2023 (2023 boundaries)". Statistics New Zealand. Retrieved 25 October 2023. (urban areas)
- ^ 2018 Census place summary: Kaingaroa-Whakarewarewa
- ^ a b "Statistical area 1 dataset for 2018 Census". Statistics New Zealand. March 2020. 7015092–7015094 and 7015096.
External links edit
- Environment Bay of Plenty - Regional Council page
- Lake Okareka Ratepayers' & Residents' Association