ABSTRACT
Irrigation systems involve both physical works and human activity. There is little need to discuss the physical works or the fact that human activity, such as management and the knowledge and effort to irrigate, are essential. High tension systems require extensive physical works and diligent management to stretch and hold the water membrane in place. Except for fully automated mechanical systems, irrigation is essentially a "happening." There are three potential management levels: the main system, the middle system, and the farmer system. The objective of the farmers who are the beneficiaries of public irrigation systems is to maximize their net benefits from irrigation by maximizing the productivity per unit of land, which is usually their scarce resource. In most irrigation projects or systems, infrastructure and/or management are such that the water is not equitably distributed to all the land. The lack of equity can occur at the main system level between unit command areas (UCAs) or within the UCAs.
