EARLy IRRIGA ION VENTURES

Press, Issue 31095, 25 June 1966, Page 10

EARLy IRRIGA ION VENTURES

Concurrently with developments in North Canterbury (referred to in an article in this page last week), there had been enthusiasm for Irrigation in Mid-Canterbury. Here the earliest recorded Irrigation system in Canterbury was constructed by a Wakanui farmer, Joseph Hunt, in 1878. In January, 1886, the Ashburton County Council discussed the question of irrigation with the result that a committee was appointed to investigate the matter. As a result of its report the council decided in January, 1887, to conduct irrigation experiments. The area chosen for these experiments was thei Elgin block reserve in the Wakanui district, and a Mr Claridge was appointed manager. Water from stock races was used to irrigate hay, clover, root and grain crops on 70 acres of light stony land. The results of these experiments were very satisfactory and the council decided that the worth of Irrigation had been proved, gome members thought the council had exceeded its powers and were relieved when the auditor made no comments on the experiments. The experiments were closed in August, 1890, and In 1891 a report of the experiments was printed. However, there would seem to be no copies of this report available now. In 1893, Mr Allan, manager of the Acton estate at Rakaia, which was owned by the New Zealand and Australia Land Company, began negotiations with the council to Irrigate from the Rakaia river. Agreement was reached on this in 1895. Again Irrigation proved its worth and the council were favourably impressed when they Inspected the results. After the experiments at Wakanui, William Baxter, engineer to the Ashburton County Council, presented a report on three schemes to irrigate part of Mid-Canter-bury. These proposals were published in 1891 and were: (a) A scheme to irrigate between the Ashburton and the Rakaia by taking water from the Rakaia at a point 60 chains north of the Rakaia gorge bridge. The cost of this scheme would have been £337,500. Part of the scheme was an B|-mile diversion tunnel which would have cost, together with headworks, £227,450. The cost of such a scheme was prohibitive.

(b) An alternative scheme required an intake at LavIngton and would have cost £60.000 and serviced 150,000 acres. The report stated that 105,000 gallons per minute was available and Baxter recommended this scheme.

(c) A scheme In which the flow of the South Ashburton river would be augmented from Lake Heron. There were two alternatives in this scheme, and both involved digging a channel from Lake Heron to a natural creek and from there to the Ashburton river via Maori lake. The Cameron river was also to be led permanently into Lake Heron. The estimate of the area that could be irrigated, allowing for percolation and loss over the long distance to be crossed, was 50,000 acres.

The first alternative was for a channel 108 chains long with a 15ft bottom set 10ft below the level of the lake. This would provide for a 4ft depth of flow in the channel drawing off at a depth of 6ft below the level of the lake. The 6ft storage would be the equivalent of five weeks’ water supply and the channel would cost £5600. On the other hand it would be possible to maintain the lake at high water level 2ft 7in above ordinary water level. An outlet 6ft below the surface and 18ft wide would cost only £4OOO. The total cost of the scheme, according to whether the smaller or larger scheme was constructed, would be £5400 and £7OOO respectively. Because of the advantage of five weeks’ storage, Baxter was in favour of the larger scheme. However, none of these three schemes was proceeded with.

In 1898 after three dry summers, settlers in the Ruapuna district requested the council to provide them with a full Irrigation scheme incorporated in the water race system. The proposal to raise loan money for the scheme was approved by the ratepayers and plans for a scheme with an intake directly below the Rangitata Gorge were drawn up. In late spring, 1898. heavy rains fell and some of the original enthusiasts forgot their previous worries of droughts. Further, they protested against the cost of the scheme and the council was forced by public opinion to change the plans for a compulsory irrigation rate. A new rate was drawn up of 6d an acre for stock water and 2s 6d an acre for irrigation. Conditions for the con struction of the intake were very unpleasant The sun shone for only a few hours. Cold winds came from the

mountains, and in winter and autumn the ground was rarely free from frost and ice. Under these conditions it proved difficult to obtain labour as men would stay for a short time only. The climatic conditions earned the intake the name “Klondyke.” About a year after the intake had been started the race was officially opened, by this time plans for irrigation had been abandoned and the race was only to supply stock water to 20,000 acres in the Ruapuna district. The interest aroused in irrigation had given rise to many meetings, but John McKeague felt that, though in the main the attenders were intelligent, they lacked any knowledge of irrigation. To remedy this deficit he wrote a book called “Practical Irrigation” which was published in 1899 by the Ashburton Mail Company. The first part of the book covered general agriculture. Ancient irrigation and irrigation in France, Spain, Italy, America, India and Australia was discussed. Chapters on results from irrigation were followed by chapters on water laws in various countries. These laws were contrasted to the laws then operating in New Zealand (Water Supply Act, 1891 and its amendments) to the disadvantage of the New Zealand law. One chapter was entitled “Irrigation and Health."

At Eyrewell, Marmaduke Dixon, using four two-horse teams, dug an lift cutting through the banks of the Waimakariri and out on to the Eyrewell district. Sluice gates were installed. He proposed to irrigate 15,000 acres of unproductive scrub land. His original experiments covered a 250-acre block and in 1891 a large gathering of farmers inspected the once useless block now covered with a vigorous growth of grass. A persistent fear was that races cut in this country would lose their water by seepage, but Dixon was able to show the shingle race floor sealed with silt He estimated he would

recover his outlay of £2OO in two seasons.

Such a demonstration generated considerable enthusiasm for irrigation. And the Wai-makariri-Ashley Water Supply Board was set up in 1892. This board turned down an offer by Dixon to dig a channel from Brown’s road to The Warren for £4OOO because it thought such a scheme would only benefit Dixon at Eyrewell. Its proposals were for intakes at Rockford and Woodstock. This stirred up a controversy which led to a court case. Leading citizens intervened and the case was adjourned. In 1896 when the system was completed it was only for stock water, the plans for irrigation having been abandoned. After this it would seem that irrigation lost its impetus in Canterbury until interest was re-awakened in the 19305. The Canterbury Progress League was largely instrumental in this revival and the Government was pressed into setting up an irrigation farm on Crown land at Seafield. Other experiments were carried out at Hororata, Motukarara, Southbridge and two trials were carried out in the Oxford area.

The results of the early experiments were reported by James (1934) and Flay and James (1934). The Hororata experiment covered six acres of stony soil and head ditches and distributary ditches cost £1 5s an acre to erect. Only a fifth of a cusec was available for irrigation and water application varied from seven to 15 inches. In March and April the irrigated areas carried 7.1 ewe hoggets, whereas the non-irrigated would only carry 1.1 ewe hoggets. The Oxford experiments

covered 20 acres and the cost of land preparation was 12s 6d an acre; five inches of water was applied In two applications and the pastures grazed by store lambs in April and May. The carrying capacity of the non-irrigated and irrigated areas was 1.3 and nine lambs respectively. The Motukarara area was irrigated with water from artesian wells. It was a dairy farm of 102 acres, occasionally flooded by Lake Ellesmere. Water was first used to leach out the salt The area observed was 76 acres. In the autumn the irrigated area carried one to two cows an acre. Unirrigated areas carried no stock. The most extensive Investigations were carried out at Seafield, 70 acres being Irrigated either by border dyke or border ditch. Land preparation costs were £9 10s an acre for border dyked areas and 13s 6d for the border ditch area.

On the dyked area, a total of 7.5 inches was applied on pastures sown in January from April 21 to June 13, and 5.4 lambs an acre were carried. The grass on the dry area was incapable of carrying stock. The border ditched area consisted of matted browntop. From January to June, 1933, the dry areas carried 0.75 dry sheep to the acre while the irrigated land carried 3.5 sheep to the acre.

The evidence from the trials was most encouraging to the proponents of irrigation. The literature carries records of the further progress of the Seafield experiments only (Flay 1935, 1936), which continued to support the case for irrigation.

This is the second part of an outline of the history of irrigation in Canterbury up to 1935 provided by the Winchmore irrigation research station. The station is seeking to gather information about the early history of irrigation in the province, according to a scientist on the station staff, Mr P. D. Fitzgerald.