 This study examined the climate and hydrology of the Ebro River basin over the past six decades. The analysis included data on climate and river flow for all 88 subbasins within the basin. The results indicated a decrease in river discharge in most of the subbasins due to a combination of factors including decreasing snowpack in the headwaters, increased evaporation rates, and increased water consumption for domestic, industrial, and agricultural purposes. Additionally, climate projections for the end of the 21st century indicate a reduced capacity for runoff generation due to increasing temperatures and less precipitation. This suggests that maintaining adequate water supplies will be a challenge for the region. This article was authored by J. I. Lopez Moreno, S. M. Vicente Serrano, E. Morantejeda, and others.