Evaluation of the agricultural water footprint and the socio-economic water productivity of the Cega-Eresma-Adaja

Worldwide water demand is increasing as a result of multiple factors including economic development, urbanization and population growth. In semi-arid countries like Spain growing water demand is creating a large number of conflicts among different users. Agriculture is often the largest water user and therefore at the core of much of the disputes over water. This work aims to develop a water footprint assessment in the Cega-Eresma-Adaja (CEA) to evaluate how water is allocated within agriculture. To this end, a water accounting exercise was performed and completed with an evaluation of the economic and social productivity of agricultural water. The assessment was carried out at the municipal scale, for the time period 2009-2013 and focused on the eight most important cultivated crops in the basin. The results of the water footprint assessment were also used to characterize CEA's agriculture through a principal component analysis. Based on the results obtained, the water footprint of the CEA has ranged between 346 and 462 hm3 during the study period. The largest share of the total agricultural water footprint (60 per cent) is linked to rain-fed agriculture. In relative terms, rain-fed agriculture has low economic and social water productivity (average of 0.40 euros/m3 and 10 jobs per hm3) but in absolute terms it generates 33 per cent of total agricultural economic revenues and 50 per cent of agricultural employment. The largest share of the water footprint of irrigated agriculture (28 per cent) is used to grow low-value crop i.e. cereals (average 16 € per m3, and 7 jobs per hm3). Only 13 per cent of the water footprint of irrigated agriculture is linked to high-value crops like carrots (average 19 € per m3, and 17 jobs per hm3). From a regional perspective, 40 per cent of the economic revenues linked to agriculture in the CEA is generated by 17 municipalities (out of 296), which accrue 27 per cent of the total water footprint. Likewise, 40 per cent of the agricultural employment is concentrated in 40 municipalities, which account for 17 per cent of the total WF. The results of this assessment provide insights on how is agricultural water currently allocated and potential options to improve agricultural water management in the CEA.