Hanmer Springs is a small town in the Canterbury region of the South Island of New Zealand, known for its hot pools. The Māori name for Hanmer Springs is Te Whakatakanga o te ngārahu o te ahi a Tamatea, which means "where the ashes of Tamatea's fire lay", referring to Tamatea, the captain of the canoe Tākitimu.
Hanmer Springs is located north-west of Christchurch and south-west of Kaikōura ( by road), in the Hurunui District. The town lies on a minor road north of State Highway 7, the northern route between Christchurch and the West Coast via Lewis Pass. The township lies at the base of Conical Hill. Mount Isobel () looks over Hanmer Springs. Jacks Pass and Jollies Pass provide access to the Molesworth and Rainbow roads.
Toponymy The town is named after Thomas Hanmer, an owner of Hawkeswood Station near the Conway River during the 1850s. Thomas Hanmer was born in Hanmer, Wales. He arrived to Lyttelton Harbour in 1852. While searching for suitable farming land, he joined a party of surveyors working in the Amuri District. During this period he was linked with Hanmer Springs, although he never lived there. He was the manager of the St Leonards Station near Culverden from 1855 to 1857. He then moved to Queensland, Australia. There is a statue of Thomas Hanmer in the centre of Hanmer Springs.
The Ngāi Tahu name for the springs in the Māori language is Te Whakatakanga o te ngārahu o te ahi a Tamatea, meaning "where the ashes of Tamatea's fire lay". The origin of the name is a legend of the ancestor Tamatea Pokai Whenua whose waka Takitimu capsized off the coast of the lower South Island. Tamatea Pokai Whenua and his party trekked north up the east coast of the South Island in freezing conditions. At the mountains that are now called Banks Peninsula, Tamatea recited a karakia (incantation), calling on the tohunga (traditional priests) in the North Island for help. The tohunga sent flames from the North Island volcanoes to warm them. As the flames travelled down from the volcanoes to Tamatea in the South Island, some flames fell along the way, creating the hot springs at the place we now know as Hanmer Springs.
History
Access to the springs In April 1859, the Lyttelton Times published a report about the hot springs by William Jones of St Leonard's station. He described seven circular pools ranging in diameter from up to with water temperatures varying from warm to almost boiling. In 1860, the Nelson Provincial Government, responsible for the region at the time, designated a reserve, covering of land surrounding the springs. Access to the general area was provided by a bridge over the Waiau Uwha River in 1864, constructed by a Mr Handisides of Nelson for NZ£2,000 to a design by John Blackett. The bridge lasted only ten years before it was blown over by a Nor'west wind.
John Turnbull Thomson surveyed the land for the township in 1879, with the total area comprising , of which were for the township itself. The hot springs were not included within that area. The springs themselves were still in their natural state at that time, with only steps and a changing shed provided. The member for , Edward George Wright, brought up the question of developing the township in the New Zealand House of Representatives in June 1882. The Minister of Lands, William Rolleston, replied that it was important that the public should retain access to the springs. Surveyor Walter Kitson was instructed with laying out the site of the hot springs including an accommodation house. Construction of a bath house began in January 1884. The fifty year jubilee was held in 1933, stating that Hanmer had been a government resort since 1883, but the centenary book pointed out that the jubilee was held a year too early. The government investing significant funds into Hanmer Springs without a bridge crossing the Waiau Uwha River caused considerable controversy. Blackett designed a new bridge and John Anderson from Christchurch won the contract to erect it, and built a foundry at the site. This second bridge opened in 1887 and gives access to Hanmer to this day, with the structure registered as a Category I heritage item since 1983. The opening celebrations held by Anderson's sons at the site were rather liberal to the extent that the site is still known as Champagne Flat.
Queen Mary Hospital
The Queen Mary Hospital for Sick and Wounded Soldiers was built on the site of the government sanatorium in Hanmer Springs. It was designed to encourage fresh air and sunlight. The Soldiers' Block was opened on 3 June 1916 by the George Russell, the Minister of Public Health. The hospital remained under military control until 1922 when it was handed over to the Department of Health. Dr Percy Chisholm continued as the medical superintendent. The Chisholm Block was opened in 1926 to treat women with nervous disorders. The Nurses' Hostel was built in 1928 in a Georgian style. In the 1960s, it changed its focus to treat alcohol and drug dependency. It closed in 2003. In 2004 the Queen Mary Hospital (Former) and Hanmer Springs Thermal Reserve Historic Area was designated as a historic site by Heritage New Zealand Within that area three buildings, the Soldiers' Block, Nurses' Home and Chisholm Block, were given Category I protection by Heritage New Zealand in 2005. The premises were purchased by the Department of Conservation in 2008.
Geology The town of Hanmer Springs is located about midway along the north side of a rhomb-shaped topographic depression approximately long and wide. This depression is part of the Hanmer basin whose maximum dimensions are approximately by . The basin floor lies at an elevation of , being surrounded by ranges up to higher. The basin has formed on a bend of the active dextral strike-slip Hope Fault within the Marlborough fault system, with alluvial sediments derived from basement rocks filling the depression. Within the town a thermal spring provides hot water used for a bathing complex.
The fault system is part of the Pacific-Australia plate boundary zone between the westward subduction of the Pacific plate east of the North Island and the oblique strike-slip of the Alpine Fault in the South Island. Tectonically the basin is a pull-apart basin between the right step-over of two segments of the Hope Fault. The western part of the basin is under transtension and actively subsiding in response to north-south extension. The eastern part of the basin is undergoing transpression in response to north-south shortening caused by convergence in strike of the Hope Fault segments across the basin.
Seismic and gravity studies indicate a wedge-shaped profile with sediments filling the basin to a depth of more than along the southern margin of the basin and thinning to less than along the northern margin. An oblique normal fault, the Hanmer Fault, runs along the northern basin-floor margin and passes about south of the thermal spring in Hanmer Springs. The Hanmer Fault probably reflects large-scale upper crustal collapse of the hanging-wall side of the Hope Fault and is inferred to intersect with the Hope Fault at depth in the upper crust. Basin formation began in the mid-to-late Pleistocene based on extrapolation of average Late Pleistocene slip rates for the Hope Fault, lack of sediments older than Pleistocene, climatic factors and the faunal content of the sediments.
Underlying the basin sediments and forming the surrounding ranges are basement rocks of the Late Jurassic to Early Cretaceous Pahau Terrane. These rocks consist of indurated thin-to-medium bedded and commonly graded sandstone and mudstone, and also thick, poorly bedded sandstone, which are collectively (and loosely) termed greywacke. The Pahau Terrane greywacke has undergone low-grade metamorphism varying from zeolite facies to prehnite-pumpellyite facies. The overlying basement-derived sediments are alluvial/fluvial fan and terrace deposits consisting of poorly sorted sandy gravel, silt, peat and clay. Glacial deposits from Late Pleistocene are also recognised. The oldest sediments are probably mid-to-late Pleistocene coinciding with the beginning of the formation of the depression.
Hot spring The hot spring at Hanmer Springs is one of about 25 hot springs located parallel to the Alpine Fault and Marlborough fault system — adjacent to the central and northern parts of the Southern Alps.
Chemical analysis of these hot springs shows a range reflecting their various tectonic settings. Hanmer Springs is closer to the southern extent of the Hikurangi Trough and has a higher concentration of chlorine, boron, sodium, potassium, lithium, strontium and barium, compared to springs further to the southwest close to the Alpine Fault. Dissolved gases in the water at Hanmer Springs are mainly nitrogen and methane derived from organic material. Subducted waters rising in the accretionary complex associated with the Hikurangi Trough consist of: pore waters derived from compaction and dewatering of accreted and subducted sediments containing organic material; water released from dehydration of marine clays and seawater. This heated mixture is modified by mixing with surface meteoric waters and heated meteoric water that has also interacted with the greywacke at a depth of at least where water temperatures reach
The high temperatures in the springs are attributed to rapid uplift of basement rocks that form the Southern Alps and nearby elevated regions. There is up to uplift each year along the central Alpine Fault region, reducing to between per year where the Hope Fault is located. The uplift is caused by the oblique collision between continental crust of the Australian plate west of the Alpine Fault, and continental crust of the Pacific plate. This collision is forcing the Pacific plate continental crust up the Alpine Fault plane and bending the edge of the Australian plate down under the weight of extra rock. The heat from uplifted basement rocks brought up to shallow levels may include minor amounts of heat generated by fault shearing.
The heated water, under pressure, rises up through faults and interconnected fractures losing heat by conduction and by mixing with cooler surface meteoric waters. When the water is discharged from the borehole at the Hanmer Springs thermal pools complex its temperature is . Since the spring's description in 1859, the natural upward flow of heated water has diminished and it is currently drawn from a borehole at about depth - depending on seasonal fluctuations. Heat exchangers cool the water down to a range of for use in the bathing pools. The Hanmer Springs Thermal Pools Reserve Management Plan 2011 states that the draw-off of thermal water will be limited to per second until the year 2039.
The thermal water from the springs contains methane gas. When the water is brought to the surface the gas is released. In the early period of the development of the springs, the gas was captured and stored for use in heating, lighting and cooking in the sanitorium. A gasometer installed in 1898 is listed as one of the historic items within the Queen Mary Hospital (Former) and Hanmer Springs Thermal Reserve Historic Area. In 2018, the pool complex commissioned a microturbine to generate electricity from the gas, reducing the electricity consumption of the complex, and avoiding the release of 100,000 cubic metres of methane into the atmosphere each year.
Demographics Hanmer Springs Hanmer Springs is described by Stats NZ as a rural settlement and covers . It had an estimated population of as of with a population density of people per km2.