Water distribution within smallholder irrigation schemes in Tanzania and its implications for economic inequality

Abstract

This thesis investigates the linkages between water supply and economic inequalities within smallholder irrigation schemes, with particular focus on Tanzania, as a key example of a developing, agrarian economy in sub-Saharan Africa. In developing countries, income inequalities are critical for poverty reduction as they determine how economic growth is distributed and, thus, to which extent the poor benefit relative to everyone else. On a global scale, and in sub-Saharan Africa in particular, poverty is most prevalent in rural areas where agriculture is the main source of livelihoods. Irrigation development is recognised as a key strategy for rural poverty reduction, although a growing body of literature questions its implications for equity and social justice. While this topic is addressed from various perspectives in the literature, there is a gap among empirical studies. Specifically, the linkages between irrigation water supply and economic inequalities at small scales have received limited attention.

To research this need, this thesis carries out quantitative, qualitative and policy investigations on two smallholder irrigation schemes in southern Tanzania. The data originates from structured household surveys, semi-structured interviews with key informants, direct infrastructure observations, maps of the irrigation schemes and documentary sources. The thesis is organised as follows: First, inequality analyses using the Gini coefficient and the Theil index are used to calculate the level and decomposition of income inequalities within six smallholder irrigation schemes in sub-Saharan Africa. Next, qualitative investigations uncover irrigators’ perspectives about the association between water supply and economic inequalities within the two Tanzanian schemes. Third, multiple regression analyses evaluate the relative impact of water supply and farm location (as well as other variables) on irrigated crop income and production within smallholder irrigation schemes. Finally, an investigation of Tanzania’s water and irrigation institutional framework highlights current policy shortfalls and possible strategies targeting greater equity of irrigation water supply.

This thesis’ findings show that high levels of income inequality exist within agricultural communities in Zimbabwe, Tanzania and Mozambique, and that such disparities are not properly considered by development polices based upon national statistics. In particular, within smallholder irrigation schemes, inequities in water supply affect economic inequalities in multiple ways, some of which – for example erosion of human capital and social stratification − are not adequately noted in previous literature. Household characteristics and farm location are also shown to be important for irrigated crop incomes and yields. While typically regarded as a good water management practice, the transfer of responsibilities to the local level is shown in this study to be problematic for traditional irrigators. Instead, in the pursuit of greater equity of water supply, participatory process should be considered based on six key equity aspects: quantity; reliability; obligations; benefits/externalities; decision-making; and land rights.

Overall, this thesis contributes the international development and inequality literature by providing a deeper understanding of: a) the effect of irrigation water supply on economic inequalities; and b) which water policies might be changed to reduce water supply inequities within traditional irrigation systems. These findings are important to respond to rural poverty in Africa, as it is at the local scale that poverty, growth and inequality interventions can be most effective. Importantly, because a large part of the world’s rural population seeks pathways out of poverty, it is critical to ensure that income-enhancing strategies, such as irrigation, do not result in aggravated economic disparities and a barrier to sustainable human development.