ABSTRACT
The manager of the irrigation system, in conjunction with local irrigators, can decide on the operating policy to best service these nominal allocations. At the start of the irrigation season the manager, after consultation with the irrigaton, announces the amount of water available for the coming year expressed as a percentage of the nominal allocation. Thus an announced allocation of 120% would mean that all irrigaton would.be entitled to 120% of their nominal allocation. As this announcement is used as a basis for the area of crop planted, a very high
de~ of reliability of attaining this announced figure is required. lrrigaton have, however, expressed a preference for this variable allocation procedure so that they can plant greater areas of crop or increase water application to existing areas when water is available.
