Kawarau Falls Dam

Junction Lake Wakatipu & Kawarau River, Central Otago

  • Kawarau Falls Dam. Kawarau Dam Bridge. Image courtesy of www.flickr.com.
    Copyright: Click . Taken By: Click - Flickr. Date: 3/02/2009.
  • Kawarau Falls Dam. Frankton area of Lake Wakatipu with Kawarau Dam Bridge in foreground (1977). Ref: AAQT 6539 W3537 182 B1458.
    Copyright: Archives New Zealand. Taken By: G Reithmaier.

List Entry Information

List Entry Status Listed List Entry Type Historic Place Category 1 Public Access Private/No Public Access
List Number 7448 Date Entered 28th May 1999

Locationopen/close

City/District Council

Queenstown-Lakes District

Region

Otago Region

Legal description

bridge adjoining Sec 4 & pt Sec 5 Blk XVIII Town of Frankton & pt Sec 1 Blk I Coneburn SD

Assessment criteriaopen/close

Historical Significance or Value

This historic place was registered under the Historic Places Act 1993. The following text is from the original Historic Place Assessment Under Section 23 Criteria report considered by the NZHPT Board at the time of registration.

Historical:

The Kawarau Dam is essentially the last remaining evidence of the high capital second stage of the gold mining days in Central Otago. It is representative of the last of the "speculators dream" projects and as such has a place not only in gold mining history but in the history of commercial development.

This historic place was registered under the Historic Places Act 1993. The following text is from the original Historic Place Assessment Under Section 23 Criteria report considered by the NZHPT Board at the time of registration.

Architectural:

The Kawarau Falls Dam was designed as a Rectangular Lift Gate type of dam. Construction of this type of darn has been in existence since at least the first Aswan Dam (Egypt) was built in 1902 using this system, and is still a valid engineering design if the site of the dam warrants it. Characteristic design indicators present at the Kawarau Darn are:

- Rectangular lift gates spanned horizontally between guide grooves in supporting piers.

- Cast iron or steel gates.

- Support guides for the gates placed vertically or inclined slightly down-stream.

- Gates raised or lowered by an overhead hoist.

- Wheels mounted on a vertical track on the downstream side of the piers, acting as part of the lift/hoist mechanism of the gates.

- Rubber or belting seals used along the sides of the gates to seal the openings. Sealing is effected by the contact pressure of water behind the gates.

- Reinforced concrete construction of the dam piers, and (where the dam is used as a road) top decking bearers.

This historic place was registered under the Historic Places Act 1993. The following text is from the original Historic Place Assessment Under Section 23 Criteria report considered by the NZHPT Board at the time of registration.

23(2)(a):

The extent to which the place reflects important or representative aspects of New Zealand history.

The Kawarau dam derives its interest from the widely held view of the time that the river beds below lakes Wakatipu, Wanaka and Hawea were rich in gold. The construction of the Kawarau dam was in pursuit of this objective in relation to the Kawarau River.

The scheme for the Kawarau dam was based on the idea of cutting off the flow out of lakes Wakatipu, Wanaka and Hawea in the winter to allow the riverbeds of the Clutha and Kawarau rivers to be worked for gold. This idea had a long history. The Inspecting Engineer, Mines, H.A. Gordon had first suggested the idea in his report to R.I. Seddon, Minister of Mines, in 1892. A similar sentiment was expressed to the Otago Institute in May 1919 by the Hon. G.M. Thomson, member of the Legislative Council.

An additional factor was the creation of a belief in what the Otago Daily Times of February 1923 called 'the fantastic plans by which it is proposed to imprison the waters that in their swift passage have from time immemorial kept guard over the possibly untold millions of pounds worth of yellow metal in the river bed.' The origin of this belief has been ascribed to a work of fiction by Sir Julius Vogel in 1889, Anno Domini 2000, in which a fictitious bonanza of two millions pounds worth of gold was extracted from the bed of the Kawarau by a method which included the damming of the Lake Wakatipu outlet. The origin of the belief may also have originated in an idea put forward in 1863 by some prospectors who were supported to some degree by a contractor named Sigley who proposed a diversion of the Molyneux (Clutha) River should it, on examination, be found to contain gold in large enough quantities. Vogel both supported and was inspired by these ideas and ultimately incorporated them in his book.

Thus, after over sixty years of germination of the idea, the Kawarau Gold Mining Company was formed in 1922, under the engineering guidance of E.J. Iles, to bring the bonanza to reality.

23(2)(b):

The association o/the place with events, persons, or ideas of importance in New Zealand history.

Events:

The Kawarau Gold Mining Company, which was formed in 1922, appears to have been the first company formed in New Zealand for the purpose of building a large concrete dam to enable gold mining activities to be carried out. The scale of the enterprise in this sense makes it representative of the so-called second stage of the gold mining days. The first stage of gold mining in New Zealand is considered to have been the stage of sluicing, stamping and dredging activities, characteristic of Central Otago mining from the 1860s through to the 1930s. Dams were not new on the scene and were built in the so-called first stage to enable gold mining to be carried out; a typical example is the shallow dam which supplied the water race upstream from the Callery's Battery at Golden Point, Macraes. The Kawarau dam, by comparison, was designed to dry out and expose the bed of the Kawarau River for mining - a seemingly impossible task which, in the end, proved to be a failure.

All of this required a huge capital investment and the floating of the Kawarau Gold Mining Company was therefore a significant event for the stock market. With engineer Iles's help, the famous criminal lawyer, Alfred Hanlon, became a major investor and was elected chairman of the company. The company gained a very generous government concession to mine the whole of the Kawarau River, a significant concession in itself. The river was divided into 128 quarter-mile claims

leasing each for £1000 plus 20% of the gold recovered. It is claimed that the proposal lead to one of the most extraordinary mining share gambles in New Zealand history. In spite of the opinion of some members of the stock exchange that the scheme was wild cat, and therefore doomed to failure, shares rose from 1 shilling to £2 in a matter of days, and eventually rose to 26 times their listed price.

The creation of the Kawarau Gold Mining Company was also a significant event for the effect it clearly had on the business of the Wardens Court, Queenstown, from 1923 unti1 1924 when the licence to build the dam was granted. The application to the court in 1923 to construct the Kawarau dam appeared to evoke fairly stiff resistance from the locals. In addition major objections were filed by the Public Works Department, Balclutha Borough Council, Clutha River Board, Cromwell Development Company, and the Southland Hospital Board. All made submissions concerning the effect on river boat navigation, hydro-power generation, and the risk of increasing flooding on the margins of lakes Wakatipu, Wanaka and Hawea, by holding water in the lakes by damming. The Public Works wanted to build a bridge across the outlet to lake Wakatipu, and this eventually became a condition for granting the licence, i.e., that the Kawarau dam should carry a roadway the width of a Public Works standard bridges.

Persons.

EJ. Iles, (1883-1960). Company Engineer for the Kawarau Gold Mining Company and designer of the Kawarau Dam. See under s23(2)(g), Architect.

Alfred Charles Hanlon (1866-1944) Lawyer, Chairman of Directors, Kawarau Gold Mining Company.

The Dictionary of New Zealand Biography accords to Alfred Hanlon the status of being "one of the most outstanding criminal advocates in New Zealand's history." Born in Dunedin and educated at Bluff, Halliwell's and Albany Street schools, Port Chalmers District High School and Otago Boy's High School, Hanlon qualified as a barrister and solicitor in 1888, setting up his own Legal practice at the age of twenty-two.In 1894 he married Mary Ann Hudson (known as Polly), daughter of Richard Hudson, founder of the biscuit making firm in Dunedin. Alfred Hanlon was appointed King's Counsel in 1930.

Hanlon made his reputation as a criminal advocate, his best known case being his defence of Minnie Dean (the Winton 'baby farmer') in 1895 which, however, is the only one of his 16 or more murder trials as senior counsel in which his client did not escape the hangman's noose. His practice also extended beyond criminal law and included divorce cases and nautical litigation. By the time Alfred Hanlon became the major investor and Chairman of the Kawarau Gold Mining Company, he had already successfully defended (1899) the premier, Richard Seddon, and the minister of marine, William Hall-Jones, against alleged irregularities within the Marine Department. He had also served two terms as President of the Otago District Law Society (1902 and 1914), one of the few to hold this position more than once.

Alfred Hanlon was famous for his elocution in court. He was the president of a number of charitable, sporting and cultural organizations, including the Dunedin Shakespeare Club. He was also known to have a penchant for gambling, and it may be no exaggeration to say that his investment in the Kawarau Gold Mining Company was one gamble that Hanlon lost.

Ideas:

The principle idea associated with the Kawarau Dam was that the bed of the Kawarau River could be seen as a kind of ideal ripple box with gold trapped in fissures in the bed rock as well as that which was retained in the silt and gravel on the river bed. The idea was to dewater parts of the river and to work the true bottom by means other than

that of conventional bucket dredges.

A proposal to dewater 11 miles of the Clutha River for gold mining was first suggested as early as 1863 by a contractor named Sigley (see above) and this had prompted Sir Julius Vogel to write to the Otago Daily Times on 20 July 1864 that Sigley's scheme should proceed without preliminary work. Vogel later incorporated the idea into his 1889 novel Anno Domini 2000, where he proposed that the Kawarau

River would be a more profitable bet for gold seekers.

The idea that a fast, powerful flowing river like the Kawarau could be dewatered at its head in order to work the bottom for gold has to be regarded as being a special and outstanding, if not a fantastic idea. Bizarre solutions for dewatering, or getting around the problem of the water, were thought of. One, in 1873, nearly caused the death of

several men when a "submarine" was built and tested in Otago Harbour. The submarine was intended to be sunk to the bottom of the Kawarau River when a trapdoor could be opened and the gold collected from the river bed: When the submarine failed to surface in one of its Otago Harbour trials it had to be hauled across mud flats to rescue the crew. Sections of the submarine are to be seen today at

the Middlemarch Museum. The following years saw the Kawarau worked by bucket dredges but it was felt that dredging was, in effect, merely scraping the surface.

The announcement in 1923 of a proposal to erect a huge concrete dam across the outflow of Lake Wakatipu was therefore hailed by the media at the time as the ultimate solution. It is interesting to note that an idea, which had been floated without any real scientific investigation sixty years before, still had such a hold over men who were literally the grandchildren of those who had first thought it up. Unfortunately,

like their grandfathers, the men of 1923 did not undertake any scientific investigations either into the feasibility of the project until a series of failures (much to the obvious chagrin of the shareholders) forced the company to hire a certain Professor Hornell in 1930 "to obtain a report as to whether the water could be so handled as to enable the

river bed to be mined." In the event the report seems to have been unfavourable, and the Kawarau Gold Mining Company was apparently wound up soon after.

23(2)(g):

The technical accomplishment or value, or design of the place.

DATE: 1924

ARCHITECT: E.J. Iles, engineer, 1883-1960

Iles was born in Wellington in 1883. He was educated at Kaikorai School, Dunedin, Otago Boys High School, and Otago University. As a student Iles had practical experience in sluice and quartz mining in Otago and on the West Coast, becoming an Associate of the Otago School of Mines. Early in his twenties, Iles moved to Thames

where he became an instructor in the Thames School of Mines, and later a Mine Manager.

Returning to Central Otago in 1910 he was involved in converting water powered stamping batteries to steam driven batteries. In 1913 he applied for water rights to bring a supply of water from the Kawarau River to Cromwell Flats for irrigation purposes. This scheme failed, however Iles was eventually asked to finish a project for damming the Kawarau River for the same purpose which had been started by the

Cromwell Development Company, but which had come to an inglorious end when one of their piers had broken in two. Iles removed the Cromwell Development Company structure and built a new dam to his own design which was able to supply enough water to be pumped up into the Ripponvale subdivision, but which was not adequate enough - as Iles had predicted - to drive the water turbine pumps at full

capacity.

At this time (1923) Iles became engineering consultant to a syndicate set up to dewater the Kawarau River at its outlet for the purpose of working the river bed for gold without the necessity for dredging. Iles proceeded to design the Kawarau Dam, completed in 1924, based on a system of control locks or gates which allowed for flood control without the risk of the dam collapsing. To work properly the full scheme

also involved, of necessity, damming the tributaries of the Kawarau River (the Shotover and Arrow Rivers) in order to gain proper control over flood levels, but as the tributary darns were never built, proper flood control was never achieved and the Kawarau dam failed in its original purpose.

Iles continued his engineering practice in Otago until his retirement when he moved to Gisborne, dying in 1960.

STYLE CODE: Dam engineering, Rectangular Lift Gate type.

DESIGN:

At a time when crude but relatively efficient Victorian timber raft dams were still being constructed in the North Island for the purpose of releasing water to carry logs downstream to the timber mill, the Kawarau Dam emerges as being by comparison a very sophisticated piece of modem reinforced concrete engineering utilising a special and outstanding system of gates for river flood control. The engineering principle behind the operation of the Kawarau Dam was little different from the operation of the Raft Dam. Both used a gate, or gates, located centrally in the middle of the dam which could be raised or lowered to allow the water behind through. In the case of the Raft Dam the purpose was to let the water act as a vehicle for logs with no hope of

stopping the flow once the gate was released, whereas in the case of the Kawarau Dam the purpose was to control the flow of water of the Kawarau River so that downstream the river was sufficiently dewatered for the river bed to be exposed and worked for gold. The origins of the engineering design behind the Kawarau Dam however, had nothing to do with vernacular raft dam construction in New Zealand. Nevertheless the contrast is mentioned here to show that New Zealand does have a tradition of sluice dam construction derived from various sources.

The design of the Kawarau Dam has been referred to as a "Stoney Roller Sluice" named after Mr. F:G.M. Stoney, a Victorian Engineer who by all accounts designed and patented a water-tight sluice gate system when he was in charge of the head works of the Madras Irrigation Canal. The design was subsequently taken up by Sir William Wilcox who designed the first Aswan Dam in Egypt for the same irrigation control purposes in 1902. The system is generally described as one where gates are constructed within a dam structure and designed to move vertically on rollers contained in independently moving frames. In the case of the Kawarau Dam these are a series of nine gates 40 ft wide and 7 ft. high. The function of the gates is to reduce, or control, the flow of the river. The operation of the Kawarau Dam is very clear in this respect, and although it has proved impossible to find a reference in present-day technical literature on the subject of dam construction to the actual term "Stoney Roller Sluice" it has proved possible to identify from the same literature that the Kawarau Dam belongs to a type of dam which is still being built called a "Rectangular Lift Gate" Dam - a term which aptly and literally describes the mechanical action of the gates on the Kawarau Dam. The defining features of this type of design are described above under criteria 23 (1). The key to the system are rollers, which reduce friction between the gate and the sides of the gate opening, and the water tight seal, which works only when there is sufficient pressure of water behind the gate to push it into the seal.

From the point of view of the apparent uniqueness of this type of dam in New Zealand we have to consider the statement that the engineer of the Kawarau Dam (E.J. Iles) contacted Sir William Wilcox, who designed the first Aswan Dam in Egypt, for his opinion on the best river control gate design. It appears to be the case that a firm of contemporary British machinery experts, Messrs. Ransomes and Rapier of London and Ipswich, held the patent rights to the Stoney Roller Sluice which Sir William Wilcox had used at Aswan, and that it was Ransomes (rather than Sir William Wilcox) who had supplied Iles with the plans and specifications for the system at his request. The success of this system at Aswan seems to have been well known to engineers and to the public alike at the time, and clearly it was also known to Lies as a system ideal for water works, irrigation and flood control, all of which were requirements for the Kawarau Dam scheme. In this sense there seems to be a clear case for saying that there was indeed a unique design association, via Ransomes and Rapier rather than directly from Sir William Wilcox, between a major dam construction in Egypt (the first Aswan Dam, 1902) and the Kawarau Dam in New

Zealand. This association was certainly emphasised by the press at the time the plans for the Kawarau Dam were first made known in 1923.

23 (2) (m):

Such additional criteria not inconsistent with those in paragraphs (a) to (k).

The Register has only one registered dam, the Arapuni Hydro-Electric Dam built 1924-29, Category 1. Unfortunately this does give one any basis for making meaningful comparisons in assessing the significance of the Kawarau Dam. R.E. Offer states that Iles's use of the Stoney Roller type of gate system at Kawarau Dam may well have been the first occasion of its use in New Zealand. This suggests that the system was used again in New Zealand, and indeed Offer also states that similar gates were being installed at the Mangahao power station at about the same time as the Kawarau Dam (1923-24). The Mangahao Hydro-Electric Power Station (Horowhenua) is registered as a Category II historic place, but not the dam. None of the supporting material on the power station registration mentions the type of construction used on the Mangahao Dam, but there appears in fact to be three reservoirs with holding dams at Mangahao, much the same as the total plan Iles

envisaged for the Kawarau Dam project, which would make the Stoney Roller system logical at Mangahao.

The problem faced here is that at the moment there is no publication available which covers in general all types of dam construction in New Zealand. However, on the basis of the evidence available, the Kawarau Dam is the only example we know of having the unique Stoney Roller gate system that is still in use. We also have to consider Offer's comment that the Kawarau Darn may have been the first in New

Zealand to use the Stoney Roller gate system. Technically, the dam is special and outstanding for the reason that it uses this system. The Handbook of Dam Engineering indicates that the roller gate dam is not a common type of construction anywhere in the world. Historically the structure is also outstanding for having been built for gold mining rather than for irrigation purposes, the latter being the standard use for this type of dam in the countries where it originated, i.e., India and Egypt.

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Additional informationopen/close

Construction Dates

Original Construction
1922 - 1926

Other Information

A copy of the original report is available from the NZHPT Southern region office

Please note that entry on the New Zealand Heritage List/Rarangi Korero identifies only the heritage values of the property concerned, and should not be construed as advice on the state of the property, or as a comment of its soundness or safety, including in regard to earthquake risk, safety in the event of fire, or insanitary conditions.