Irrigation Water Shortages and Intra-Scheme Variation in Farmers' Trust: Evidence from Tanzania

Although irrigation is crucial for improving agricultural productivity and food security in sub-Saharan Africa, it is widely recognized as underperforming. This study examines how irrigation water shortages during the rice-growing season are associated with trust among irrigation users; trust is a key form of social capital that underpins collective action in common-pool resource management. Using the Lower Moshi Irrigation Scheme in Tanzania as a case study, we measured variations in irrigation users’ trust levels toward other users in different parts of the scheme. The results show that trust levels were lower toward users located farther away within the scheme. Moreover, the results provide suggestive evidence that farmers with plots experiencing water shortages tended to exhibit a larger trust gap between nearby users and users in other parts of the scheme. The study highlights the importance of transparent information sharing on water allocation and identifying the actual causes of water shortages to prevent unnecessary trust deterioration among users.