Incorporating the water footprint and environmental water requirements into policy: Reflections from the Doñana Region (Spain)
ABSTRACT: This chapter is a preliminary hydrologic and economic analysis of the water footprint and environmental water requirements in the Doñana region, which includes the Doñana National and Natural Parks and its surroundings. This region is located at the coastal end of the Guadalquivir valley and comprises the marshes and estuary of the Guadalquivir river in southwestern Spain. It preserves one of the largest and most important remaining wetlands in Europe. This initial analysis shows that the environment is the main water user amounting to about 59% of total water use, followed by agriculture with around 40%, and urban and industrial water supply 1%, for an average rainfall year. The green water use by forests represents about 44% of the total water use. Groundwater is also a key factor. It is well known since decades that the small but meaningful depletion of the water table due to groundwater abstraction for irrigation, for urban water supply, and by eucalyptus plantations, has an impact on the natural vegetation. Following the ELOHA approach (Ecological Limits of Hydrologic Alteration) the theoretical environmental flows in the Doñana region, needed to recover the wetlands, amount to about 200Mm3/yr including surface and groundwater bodies in average years. The blue water available for human use (total surface and groundwater available minus environmental water requirements) is lower than the agricultural blue water footprint alone (243 and 282Mm3/yr, respectively).Within agriculture however the largest amount of blue water is used to produce water-intensive low-economic value crops such as rice. These preliminary results seem to indicate that the application of an integrated approach using the water footprint and environmental water requirement analysis, could improve the practice of water resources planning and management, the preservation of ecosystems and the associated livelihoods.