ABSTRACT
The world now contains many dozens of large gravity canal systems that are run by technical bureaucracies. In some of them the Operation and Maintenance (O & M) responsibilities of the staff are brought right down to the farmgate (the Gezira scheme is the archetype; Farbrother, 1973). But in many such systems the technical staff do not have this responsibility, and in consequence there is a sort of "no-man's canal" area, between the outlet and the farmgate, where neither the technical staff nor the farmers have effective control over, or responsibility for, O & M activities (Lowdermilk, 1986). There are undoubtedly many causes for this, including "illegal" occupation of land, and lack of money or personnel for the bureaucracy. Whatever the reasons, the effects of this lack of maintenance are the deterioration of these parts of the system, marginal or inadequate deliveries of water to farmers at the tail end of these areas, and aggregate production levels that are lower than necessary. This amounts to inefficient use of water, capital, and land, and is widely seen as a serious problem.
