Recent data from the Ministry of Ecological Transition and Demographic Challenge show a modest weekly decline in reservoir volume, with losses totaling 705 cubic meters. This marks 1.3 percent of overall capacity, leaving the system at 21,291 cubic hectometers, which corresponds to 37.9 percent of full storage. In practical terms, the reservoirs now hold less than half of their potential, illustrating the ongoing strain on water resources across the country.
Compared with the decade’s average, current storage sits 10,638 cubic hectometers below the norm. The shortfall is even more pronounced when measured against the same period last year, where storage stands just over 4,000 cubic hectometers lower. This gap highlights a continuing pattern of below-average reserves that has persisted through the year.
To identify figures lower than these, one would have to go back to 1995. In the week ending August 27 of that year, Spanish reservoirs failed to accumulate 15,000 cubic meters of water, according to data collected by the Ministry and reported by Europa Press. The contrast underscores how exceptional today’s figures are within the historical record, even as regional variability remains significant.
Recent rainfall favored the Atlantic side while the Mediterranean corridor remained relatively dry, as explained by the department led by Teresa Ribera. Local precipitation in some areas registered a maximum of 14.2 millimeters (14.2 liters per square meter), underscoring the uneven distribution of rainfall during the period.
State of each reservoir: eastern Cantabria holds at 69.9 percent capacity, while western Cantabria sits at 60.4 percent. In Miño-Sil, reserves stand at 49.9 percent, and in Galicia Costa they maintain 59.9 percent. Inland basins in the Basque Country reached 81 percent. The Tinto, Odiel, and Piedras basins are at 68.6 percent; Júcar at 57.3 percent, and Ebro at 48.5 percent, illustrating a mosaic of storage levels across regions.
Overall, eight watersheds show less than half of their capacity. Notable examples include the Duero basin at 40.6 percent, the Tagus at 39.5 percent, and the Guadalete-Barbate and Guadalquivir basins at 26.3 percent and 23.2 percent respectively. In the Andalusian Mediterranean basin, storage is around 43.8 percent, while Segura sits at 39.2 percent. Catalonia’s inner basins average about 40.9 percent, reflecting the broad regional disparities in reservoir levels.
These figures illustrate the ongoing and regionally varied challenges facing Spain’s water management system, as rainfall patterns continue to influence inflows and storage capacity across the year. Authorities monitor these trends closely to guide conservation efforts, agricultural planning, and urban water supply strategies across the country.
Credit for the data goes to the Ministry of Ecological Transition and Demographic Challenge, which maintains ongoing surveillance of reservoir levels and rainfall patterns to inform policy and public awareness.