Stock Water Supply

Press, Volume CII, Issue 30146, 1 June 1963, Page 6

Stock Water Supply

TN recent drought seasons -*■ the importance of a dependable stock water supply has frequently been emphasised. In the Montalto district, on the north bank of the Rangitata river, about 25 miles west of Ashburton, the lack of such a waiter supply has been a factor limiting production for many years, and subdivision of properties and a trend for some farmers to run cattle has further accentuated the problem in recent years. The district has had a waiter race system based on the gorge of the south branch of the Hinds river, but in this inaccessible region of shifting shingle, with the intake occasionally being left high and dry, and porous country, the supply has been a fickle one. Mr B E. Lili chairman of the committee of ratepayers which has been associated with the Ashburton County Council in providing a new water supply system, recalled this week that he had known the water to be off for three weeks at a time on his property towards the end of the old waiter race system. He sand that when he was running about a ewe and a half to the acre on his 1000-acre property, it had been necessary tc cart 20,000 to 30,000 gallons of water to the stock every season, and when two seasons ago he increased his flpek to 2800, with 50 calves as well, he found that he had to cart 600 to 800 gallons of water a day to the cattle alone, and by the beginning of November that year 25,000 gallons of water had been transported. Mr Lili said that with the completion of the water supply system last November, the development of the district could now go ahead. It is estimated that much of the country in this district, with a rainfall of about

35 to 40 inches, would be capable of carrying four and a half ewes to the acre. One of the authors of the present scheme has been Dr. R. D. Morrow, of Christchurch, whose grandfather was a pioneer settler in the area. Dr. Morrow is still a landholder in the district, and he did much of the spadework for the scheme in determining the measure of Government and local body support it would attract. Of a number of schemes which were mooted, one put forward by the Ashburton County Council’s chief engineer, Mr R. L. Lindsay, commanded general favour. It provided for a gravity system based on a spring-fed swamp s upplemented by pumping from the Rangitata. The ratepayers officially approved the scheme at a meeting in March, 1957, and work began about three years later when a 28-foot deep well with a 27-inch casing was sunk on the north side of the Rangitata close to the intake for the AshburtonLyndhurst irrigation scheme. One Of the most difficult sections of the scheme was constructed in the winter of 1961. It was the installation of the 4-irich main, lifting the water 30ftft up two terraces on the north side of the river to a reservoir. For some 3Qoft up the first terrace the gradient was about one in one and a half and this involved same hazardous bulldozing to cut a channel for the steel pipe. The installation of the main and the reservoir was undertaken by Burnetts Motors. An idea of the degree of difficulty involved in the main is given by the fact that while the pipe cost 7s a foot, the cost of laying it was 20s a foot.

Towards the end of 1961 a. reinforced concrete reservoir) was constructed on the top of the second terrace to hold 90,000 gallons of water, which is a day’s supply for the scheme, and two 25-horse-power submersible pumps, each capable of delivering 7000 gallons of water an hour, were installed. These are arranged for alternate use and in -the event of the power failing there is provision for a diesel generator being linked up to drive the pumps. Use Of Pumps Actually the pumps may have to be used for only a month or two a year as water is also directed into the reservoir from a nearby swamp which collects run-off from neighbouring higher country. Ditches cut in the swamp help to bring the water into the system. From the reservoir the water flows by gravity through 63 miles of alkathen* pipe laid to serve 21 ratenayems occupying about 11300 acres. Laying of the alkathene began last June and was completed about Vbvember A grader was used to cut the channels for rhe piping which was laid at up to 2ft underground It is believed that this is one of the largest lengths of plastic piping to have been used in a single project in the South-1 em Hemisphere In a straight line it would stretch i from about Hinds to Christ-1 church The pipe range® in sizes from 5-inch down to t-inch. The scheme was designed to provide about 6 gallons cf water to the acre and some 320 concrete troughs ■ith ballcocks in the bottom as a protection against freezing and with check valves to prevent the water running back into the system, have been installed with two paddocks being served by the one trough laid crossways under a fence. The cost of the scheme is put ait £46.600. On a £1 for £2 basis the Government is providing £16.000 and the county council is contributing a similar subsidy on the balance—a contribution of £10.867. This leaves the ratepayers to pay £21,733 and they are paying this back to the council over five years at 12s 6d an acre annually. They have already made payments for two years. When the loan is repaid it is estimated that maintenance will cost about Is 5d an acre, but this is dependent on such factors ae. the amount of water which will have to be pumped from th** rtwr