and length of bottom intake perforations to provide maximum intake area, while excluding ﬁnes and sand. Final well development is a ﬂushing designed to remove ﬁnes in the pipe intake vicinity, thus providing near sand free quality. The issue as to whether present exhortation reconversation is necessary or a convenient ﬁscal matter, time may tell.
Having explored the water source proportion, irrigation use started to become evident following the Second World War and accelerated in the ﬁfties and particularly in the sixties. Locally early postwar, small metal pipes could be observed watering very limited areas of the more valuable crops, particularly strawberries and the like.
Small petrol engines and pumps were used to provide more pressure, usually fed from 2” essentially domestic wells, which were then quite common. Larger 3” or 4” wells were somewhat rare and often restricted to commercial manufacturing, or freezing works. The introduction of joinable aluminum [ aluminium ] pipes in various diameters and lengths created increasing irrigation interest, together with larger internal combustion engines/pumps and some electrical installati[JMD Elsea ons. Most of this expansion was driven by the vegetable production requirements of the local manufacturers, notably, Watties, now Heinz-Wattie. Various commercial ﬁrms started supplying complete systems of pipes and pumps. Locally, Agnews were providers, and the logo “Irrigation by Agnews” became familiar. Orchard under tree irrigation also became a valuable tool in the orchard business, then frost protection.
After a somewhat stuttering start, most users realized the limitations of supply, both in well size and pipe diameter reticulation. Three inch and four inch pipe became commonplace, with some 5 inch in the large user. Aluminum was most preferred for lightness, although some German Perrot brand steel was used, with the advantage of durability. Lightness was almost paramount, as the chore of constantly moving the set-up across large areas was very labour intensive, to say the least, and as wind factors were usually less at night, and time was of the essence, night shifting of pipes, usually every 4 hours or so, became essential this ensured the future of aluminum. Nothing more disheartening was to have shifted a long line of pipes, giving due allowance for wind effects, than to be faced with a wind direction change necessitating a further adjustment. Other major irritators involved blow-outs and leaks, which added to the everyday burden. One acre inch of water represents about 24,000 gallons (110,000 litres) which is generally the maximum which can be extracted from 4 inch (100mm) wells. This limitation saw the introduction of 6 and 8 inch, even 10 inch industrial type well to cater for the larger installations, and ﬁxed permanent orchard buried supply systems.
Towards the seventies, manufacturers started supplying traveler type of units, which were designed to reduce the labour content of shifting pipes. These units generally followed the pattern of a large diameter drum, on which was wound heavy polypropylene plastic type hose of large internal bore sizes (125”/ 150mm) which carried enough length to cover a useful area. There were several variations of these irrigators, with one type being unwound prior to starting. and using mechanical gearing, driven by an over-head rotating sprinkler to slowly move the