Effects of drip irrigation promotion policies on water use and irrigation costs in Valencia, Spain

The aim of this study is to conduct an ex post analysis of the generalized implementation of drip irrigation in the last two decades in the Valencia Region (Spain). Due to the important role played by water users' associations (WUAs) in this socio-technological change in the region, this research was based on 77 interviews with different WUAs that provided information prior and subsequent to modernization. Firstly, we review the published studies concerning the effects generated by this technological change and describe the drip irrigation promotion policies implemented by national and regional governments. Subsequently, we analyse the consequences for irrigation associations, including effects on water use and irrigation costs. The reduction of water withdrawals has been generally significant. This was possible because the regional contextual factors prevented, in most cases, crop intensification and areal expansion. Nevertheless, due to the enormous investment effort and the resulting maintenance costs, the technological change has increased irrigation costs, generating some uncertainties concerning the financial sustainability of some WUAs. In conclusion, a thorough assessment of contextual factors and accompanying measures such as technical assistance and monitoring appear to be indispensable to avoid unforeseen effects and to achieve the potential goals of conversion to drip technologies.