Is small better? A comparison of the effect of large and small dams on cropland productivity in South Africa

We estimate and compare the effects of small and large irrigation dams on cropland productivity in South Africa (SA). To this end we construct a panel data set of SA river basins. The econometric analysis reveals that while large dams increase cropland productivity downstream, they have a negative effect on cropland within the vicinity. However, their existence can enhance the relatively small positive impact of local small dams. While a cost-benefit analysis of irrigation benefits does indeed show that small dams per se may be more viable than large ones, large dams can play a potentially important role within a system of both types.