Interest In Irrigation In Early Canterbury

Press, Volume CVI, Issue 31089, 18 June 1966, Page 10

Interest In Irrigation In Early Canterbury

Water has always been a problem in Canterbury as its rivers flow straight from the mountains to the sea with barely any tributaries. However, men of vision could see what could be done to the plains by provision of water races for irrigation and stock water. Through their drive they aroused public opinion to such an extent that the latter part of the nineteenth century saw a large part of the plains crossed by races providing water for stock and domestic purposes.

The greatest of these pioneers was Colonel de Renzie Brett and his efforts to have the plains watered are recognised by a memorial at Kirwee. Brett was bom in Ireland and served in the Indian Army. While in India he had observed what benefits irrigation could bring. Shortly after his arrival at Lyttelton in 1865 he became convinced that the plains could be irrigated. He discussed his ideas with C. E. Fooks, an early Canterbury engineer, and found that they were practicable. Thereafter he tried to get public opinion behind him to have such schemes constructed. Most people realised that considerable benefit could be obtained from watering the plains but thought seepage losses would be excessive. An editorial in the "Lyttelton Times” in 1867 suggested irrigating the plains from artesian bores.

The Provincial Council was apathetic and to arouse them Brett stood for the Selwyn district and was elected in

1870. In 1871 he succeeded in a motion that the council make a survey of the district to divert part of the Waimakariri from the lower gorge along the plains to RolTeston, and that 1500 acres of Crown land be vested in compensation for the cost of the scheme. As a result Fooks was commissioned to make a survey of the area bounded by the Kowai, Hawkins and Waimakariri rivers north and north-west of Sheffield.

The report of Fooks ruled out the Waimakariri as a source of supply as its channel shifted with floods and also because of the considerable cost if water had to be raised from the Waimakariri over terraced banks to the level of the plain. He recommended that the Kowai river be tapped at a site above its junction with the Waimakariri. Objections were raised to his open races because it was held that the topsoil would be removed in time leaving a porous substrata. Fooks main-

tained that if the main channel was provided with branching loop lines scouring would be avoided. In 1872, because of other committments, money set aside for irrigation was held over to a future date. When the matter was reopened divided opinion over the open race led to a second survey being commissioned. The engineer appointed for the survey was Henry Wrigg, from Auckland. His survey supported Fooks’s scheme but he recommended zig-zag channels, 60 miles in length, to reduce the speed of the water, instead of loop lines. This had the additional advantage of avoiding long lead Tines from the main channel. As a result of this survey public interest was again aroused and Brett drafted a bill for the General Assembly which would have given the Provincial Council control of water races, but this was rejected. The following year, 1874, however, saw a simitar bill succeed. The Canterbury Water Supply Act empowered the council to enter upon and take possession of any lands, dam water, or reserve any part of the waste lands of the Crown for the purpose of constructing races. Powers to regulate the flow, maintain races and levy charges were also granted. However, in 1874 the movement for abolition of the provinces caused a cessation of activity in the water supply field.

People who had bought land south of the Waimakariri in anticipation of the construction of water races were naturally not very pleased at this. Eventually they were able to exert sufficient pressure on the council to make it act. Fraser Brothers tendered to construct the intake and the first two miles of the channel for £13,000. The zig zag channel was to be replaced by a single straight race to Sheffield, where it branched and the force of water was to be controlled by falls. The construction of a tunnel across the terraces was replaced by Fook’s plan for an open race. After the abolition of the provinces water race control passed to the Selwyn County Council in 1877. The intake and dam had been considerably damaged by floods in 1876 and this had prolonged the work. However in December, 1877, the dam and two miles of the race were officially opened. The county council appointed John Webster, an engineer, to investigate further extensions of the race and this was gradually constructed to Sheffield. However, Webster could not convince the council of the damage that could result to the intake in the event of floods unless flood gates were built. In 1879 he was proved right when floods damaged the intake and scoured the tops of the race down to the shingle. To further extend the races

a local poll approved a loan of £35,000 to raise funds in 1880, and by 1881 the plains between the Hawkins, Selwyn and Waimakariri rivers were drawing water from the Malvern race. Although both Fooks and Wrigg had opposed the Waimakariri as a source of irrigation water the Selwyn County Council decided that this alone would provide a sufficient supply. Accordingly they obtained permission from the South Waimakariri River Board to construct intakes at Halkett. In 1888 the races were completed spreading over an area from Halkett to Harewood. As the Malvern race could not supply sufficient water for both stock and irrigation, the Selwyn County Council planned to construct an intake from the Waimakariri gorge, across the terraces and on to the plains hoping that this would supply sufficient water for irrigation. In spite of considerable difficulties the race was opened in 1891. However the project was too ambitious and sections of the terraces collapsed owing to their steepness. In 1907 the project was finally abandoned. Apart from a new intake constructed in 1908 below Halkett, the water race system was virtually completed and the original intentions of irrigation had been abandoned. (To be continued.)