Development At Winchmore

Press, Volume XCVIII, Issue 28820, 14 February 1959, Page 9

Development At Winchmore

An automatic Irrigation system has. long been the need of farmers relying on applied water for their maintenance of production. Worh which Is being done at the Winehmore Irrigation research station of ' the Department of Agriculture has resulted in a time release device which has passed the experimental stage and Is now being developed. Designed by Mr A. D. Hall, instructor in agriculture, at Ashburton, the automatic release-con-sists of a bomb release connected to. an alarm clock. To thia is connected the bottom corners of a sheet dam placed across the water channel by means of two chains, and the top of the sheet is held rigid across the channel by a heavy pipe. When the pre-set alarm goes off at the stage when sufficient water has been applied through the headgate the bottom chains are released and the weight of the water dammed up by the sheet sweeps straight through and down to the next sheet dam. Portable System The main feature in any automatic system for irrigation is that it should .be versatile and economic. This has been kept in mind by Mr Hall and his system is portable. The only permanent structures used are concrete spillways and divider boards built into the channel side. To save expense these headgates have been installed in line with every second levee or dike to enable two borders to be irrigated at once. This halves the number,of sheets and release mechanisms needed. The divider board ensures an equal amount of water flowing on to each border.

The headgates each have a hinged watertight flap door which closes when the release gear lets go the sheet and prevents any backing up of the water from the sheet next below spilling over on to the areas already watered. So far the research station has constructed 24 sets of sheets and time releases and this is sufficient for the 160-acre block which has been turned over to an “all grass” farming system trial under automatic irrigation. Members of the Parliamentary select committee on irrigation who visited Winehmore this week were impressed with the potential increase in irrigating efficiency offered by this method. and the accompanying photographs were taken during a demonstration given before .the committee on Monday. In the first photograph the sheet is kept in position agginst the sides of the water channel by the weight of the water, but there is sufficient leakage getting past to the next sheet to keep it in place. The chains holding the bottom of the sheet can be seen passing across the water and around the belaying post to the release gear and alarm clock and the Open headgate is allowing the water to flow freely on to the borders. The divider board can be seen in operation.

-When Release Operates

Immediately the release operates, the water sweeps the sheet upwards and the headgate flap closes as can be seen in the second photograph. The water level drops until the next sheet fills completely and the water flows through the headgates on to the new borders.