Lake Rotoroa or Hamilton Lake (officially Lake Rotoroa / Hamilton Lake) is a lake in Hamilton, Waikato, North Island, New Zealand. It has a surface area of about 54 hectares (133 acres)[2] and an average depth of 2.4 metres (7 ft 10 in).[3] It is the home of the Hamilton Yacht Club, which holds regular sailing in the summer.[4]
| Lake Rotoroa / Hamilton Lake | |
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.png)  Lake Rotoroa / Hamilton Lake Location of Lake Rotoroa / Hamilton Lake in New Zealand | |
| Location | Hamilton, Waikato, North Island |
| Coordinates | 37°47′56″S 175°16′26″E / 37.799°S 175.274°E |
| Type | eutrophic |
| Primary outflows | Waitawhiriwhiri Stream |
| Catchment area | 258 ha (640 acres)[1] |
| Basin countries | New Zealand |
| Surface area | 54 ha (130 acres) |
| Average depth | 2.4 m (7 ft 10 in) |
| Max. depth | 6 m (20 ft) |
| Water volume | 1.3 km3 (1,100,000 acre⋅ft) |
| Residence time | approx. 2 years |
| Surface elevation | 37.15 metres (121.9 ft) |
Lake Rotoroa formed, like most of the lakes in the central Waikato (Hamilton) basin, about 20,000 years ago, after the Waikato changed course to flow out at Port Waikato, rather than at Thames. It was a high-energy, braided river carrying large volumes of volcanogenic sediment (Hinuera Formation), which was deposited over and around a pre-existing hilly landscape to form an alluvial plain. In the process of depositing the alluvium, small basins were formed adjacent to the hills, and water then accumulated from local drainage and groundwater in these small basins. At Rotoroa, initially two small shallow lakes were formed with clear water in an embayment of the partially enclosing hills, a low spur off the hills separating them. Peat growth in the adjacent Rukuhia bog to the west and south then expanded and deepened as net precipitation increased as climate became warmer and wetter in the region, lifting regional water tables. The peat then encroached on to the alluvial dam holding in the two shallow lakes, forming a second storey barrier on top so that the two lakes coalesced into a single deeper lake with brownish peat-stained water, submerging the low spur.[5]
Innes Common, to the west, is 28 hectares (68 acres) of former wetland, bought by the Domain Board to protect the lake[6] and drained some time after 1883.[7] It was named after the Innes family from 1956.[8]
Near the cafe, a shelter covers the old locomotive, F230, donated in 1957.
On Ruakiwi Rd an ivy-covered memorial arch[9] to Arthur Swarbrick, former chairman of the Hamilton Domain Board, dates from 1929.[10]
The lake is sometimes affected by cyanobacteria, due to its high nutrient levels.[11] However, the eutrophic quality of the lake has improved since 1998 due to regrowth of macrophytes,[12] such as charophytes.[13]
In 1959, 11,000 litres (388 cu ft) of sodium arsenate was poured in the lake to control weeds. Arsenic is still in the sediment and eating fish from the lake is not recommended;[14] it is on Regional Council's contaminated sites list. Copper, lead, mercury and zinc also exceed the Australian and New Zealand Environment and Conservation Council (ANZECC) guideline value in parts of the lake.[15]
On 26 August 2021, the official dual name of the lake was standardised as Lake Rotoroa / Hamilton Lake, having previously been Lake Rotoroa (Hamilton Lake) since 1974.[16]
Sports
editLake Rotoroa is a venue for many sports.
At Innes Common, a park on the west side of the lake is the Waikato Hockey Association Sports Ground.
Innes Common also provides the best access to the lake for watersports. Small sailing boats and canoes are frequently seen on the lake. The lake is home to Hamilton Yacht Club which has been at the lake since 1938. The yacht club has members sailing Optimists, P Class, Starlings, ILCAs and Zephyrs with the occasional Frostbite still to be seen. It also holds a Learn to Sail programme and has regular racing on Wednesday evening and Saturday afternoons during the summer https://hyc.org.nz/. The lake is also popular for Waka Ama and Dragon Boating. The lake is too small for rowing skiffs because as soon as they get up to top speed they have to stop. The lake is better suited to slower boats that can turn easily. Powerboats are not permitted on the lake except for official council purposes and safety/coach boats.
The 3.8-kilometre (2.4 mi) scenic path around the lake makes it a suitable venue for walking and running. The Hamilton Road Runners Club is based at the Hamilton Yacht Club and meets there for runs every Thursday evening and Saturday morning, as well as hosting a running event at the lake each year in summer.[17] There are water fountains at the playground at the north-west side of the lake and also at Innes Common.
There are also short bush walks and a small golf green[citation needed] on the west side of the lake.
References
edit- ^ Waikato Regional Council Technical Report 2014/59 Waikato region shallow lakes management plan: Volume 2
- ^ "EW Lake Rotoroa". Archived from the original on 19 October 2007. Retrieved 2 December 2007.
- ^ "Lake Rotoroa". Archived from the original on 4 July 2007. Retrieved 2 December 2007.
- ^ "Hamilton Yacht Club". Retrieved 2 December 2007.
- ^ Lowe, D. J. (2010). "Introduction to the landscapes and soils of the Hamilton Basin" (PDF).
- ^ "Airport for Hamilton". Auckland Star. 2 October 1929. p. 7. Retrieved 28 September 2017.
- ^ "Hamilton Domain Board". Waikato Times. 10 November 1883. p. 2. Retrieved 28 September 2017.
- ^ "Opening of Innes Common". Hamilton. Retrieved 28 September 2017.
- ^ Ann Mcewan (14 November 2011). "Memory Boxes". Waikato Times. Retrieved 28 September 2017 – via PressReader.
- ^ "To the Memory of a Well – Known Waikato Resident. (the Gateway Erected at the Entrance to the Hamilton Lake in Memory of the Late Mr. Arthur Swarbrick, for Many Years Chairman of the Hamilton Domain Board". New Zealand Herald. 8 May 1929. p. 8. Retrieved 28 September 2017.
- ^ "Hamilton Lake Domain - Hamilton City Council". www.hamilton.govt.nz. Retrieved 28 September 2017.
- ^ "Lake Rotoroa". Waikato Regional Council. Retrieved 28 September 2017.
- ^ "Lake Rotoroa: an ancient lake makes a comeback". Stuff. Retrieved 28 September 2017.
- ^ "Hamilton Lake Domain Management Plan" (PDF). 2017.
- ^ Rumsby, Andrew (March 2008). "Significance of Arsenic in Sediments of Lake Rotoroa (Hamilton Lake)" (PDF). Environment Waikato.
- ^ "Amendments to standardise existing official dual names — New Zealand Geographic Board Ngā Pou Taunaha o Aotearoa". New Zealand Gazette. 26 August 2021. Retrieved 3 November 2021.
- ^ "Fun Run Summer Series in Hamilton, New Zealand". Retrieved 6 August 2017.
- Green, J.D. and Lowe, D.J. 1994. Origins and development. In: Clayton, J.S.; de Winton, M.D. (eds) “Lake Rotoroa: Change in an Urban Lake”. National Institute of Water & Atmospheric Research Ecosystems Publication 9, 13–23.
- Hewitt, A.E., Balks, M.R., and Lowe, D.J. 2021. Chapter 8: Organic Soils. In: "The Soils of Aotearoa New Zealand" (1st ed). Springer, Cham, pp. 113–132.
- Lowe, D.J. 2014. How the lake [Lake Rotoroa] was formed: influence of the ancestral Waikato River. In: Taylor, J. “Hamilton Lake – City Playground”. Published by Jeff Taylor, Hamilton, pp. 6–13.
- Lowe, D.J. 2021. Introduction to the landscapes and soils of the Hamilton Basin and South Waikato: Field notes. School of Science, University of Waikato, Hamilton. 36 pp. DOI: 10.13140/RG.2.2.36071.39845
- Lowe, D.J. and Green, J.D. 1992. Lakes. In: Soons, J.M., Selby, M.J. (eds) Landforms of New Zealand, 2nd edition. Longman Paul, Auckland, pp. 107–143.
- McCraw, J.D. 2011. The Wandering River. Landforms and geological history of the Hamilton Basin. GSNZ Guidebook 16. Geosciences Society of New Zealand. 88pp.
External links
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Media related to Lake Rotoroa, Waikato at Wikimedia Commons- Hamilton Kete - timeline of reserve history from 1800
- 86 photos of lake
