In recent years, local users have been considered to be more effective managers of natural resources, especially considering the frequent failure of state-based resource management (Mosse, 1999). The current trend of transferring management responsibilities to users builds on this conviction. In particular, large-scale smallholder irrigation schemes have been subject to irrigation management transfer (IMT) in the past few decades. Farmers are now involved in the operation and maintenance of hydraulic infrastructure, financing and decision-making on the cropping pattern and the physical and institutional layout of the irrigation scheme (Groenfeldt and Svendsen, 2000). Most often, however, transfer of responsibilities has been imposed on them and it is not evident that farmers are able or willing to take on the complex management tasks (Le Gal et al, 2001; Meinzen-Dick et al, 2002). First, it requires a radical mentality shift from farmers who until then depended completely on the management for decision-making (Shah et al, 2002). Second, it demands a considerable understanding of the importance and functioning of the different management tasks and requires the availability of necessary information (De Nys, 2004). Third, the collective action problems inherent in such transfers also have to be surmounted through the drawing up of institutional arrangements. This is particularly so given the fact that individual farmers have an incentive to extract more water and invest less in maintenance than is optimal at the collective level (Tang, 1992). The Office du Niger in Mali is an interesting case for evaluating some of these issues by considering the experiment of management transfer in collective irrigation schemes. The objective of this study is therefore to diagnose farmers' water management at the tertiary level, focusing on two principal activities of water management: water distribution and maintenance. The chapter first explains the setting and background of managem