We examine the shifting farming system around the small hill dams in northwestern Tunisia. A socio-economic questionnaire was given to a sample of farmers using water from eight representative small hill dams. Cluster analysis was used to establish farmer groups before and after creation of the reservoirs. Before the creation of hill dams, farmers were grouped into two clusters. Afterwards, three new farming systems emerged. The main differences between these groups are farm area, cropping system, irrigation practice, livestock type and number, and income. Following construction of the small hill dams farmers increased the extent of fruit tree cultivation, introduced irrigation practices, and augmented livestock herd size and production. Farmer income increased with the availability of water in the hill dam reservoirs.