Spain’s Reservoirs Drop to 75.3% Capacity but Water Reserves Remain Above Average
Spain’s reservoir levels continue to decline as summer temperatures intensify, but the country’s overall water reserves remain in a much stronger position than in recent years. According to the latest figures released by the Ministry for the Ecological Transition and the Demographic Challenge (MITECO), Spain’s reservoirs are now at 75.3% of their total storage capacity, following a weekly loss of 1,007 cubic hectometers (hm³).
Despite the seasonal decline, Spanish reservoirs currently hold 42,192 hm³ of water, providing a comfortable buffer to meet domestic, agricultural, industrial, and environmental demand throughout the summer. The current volume is significantly higher than both the amount stored at the same time last year and the average recorded over the past decade.
While the situation remains favorable nationwide, weather conditions during the coming weeks will play a key role in determining how quickly water reserves continue to decrease.
Summer Heat Accelerates Water Loss
Reservoir levels typically decline during the summer months as temperatures rise and rainfall becomes less frequent. High temperatures increase evaporation rates, while water consumption also grows due to greater household demand, irrigation needs, tourism, and agricultural activity.
During the latest reporting period, rainfall was concentrated mainly across Spain’s Atlantic regions, while most Mediterranean areas experienced very little precipitation.
The highest rainfall was recorded in Santiago de Compostela, where 51.8 millimeters of rain fell. However, these localized showers were not enough to offset water losses across the country.
As a result, Spain’s overall water reserves declined by 1.8% compared with the previous week, a decrease considered typical for this time of year.
Ebro Basin Records the Largest Weekly Decline
Water losses varied considerably across Spain’s river basins.
The Ebro River Basin recorded the largest weekly decline, losing 3.4% of its stored water.
It was followed by:
- Duero Basin: -2.7%
- Western Cantabrian Basin: -2.4%
- Miño-Sil Basin: -2.4%
Other important river basins, including the Tagus (Tajo), Guadiana, Guadalquivir, Galicia Costa, Guadalete-Barbate, Tinto-Odiel-Piedras, the Andalusian Mediterranean Basin, Júcar, Segura, and the Internal Basins of Catalonia also experienced moderate decreases ranging from 1% to 2%.
These reductions reflect the combined effects of rising temperatures, increased water demand, and limited rainfall across much of Spain.
Only Two River Basins Remain Stable
Among Spain’s major water management areas, only two managed to maintain stable storage levels during the past week.
The Internal Basins of the Basque Country remain at 85.7% of capacity, while the Eastern Cantabrian Basin continues at 78.1%.
These regions benefited from more consistent rainfall than much of the rest of the country, highlighting the climatic differences between northern Atlantic Spain and the drier Mediterranean regions.
Current Reservoir Levels Across Spain
According to MITECO, reservoir storage currently stands at the following levels:
- Eastern Cantabrian: 78.1%
- Western Cantabrian: 79.8%
- Miño-Sil: 76.0%
- Galicia Costa: 65.8%
- Internal Basins of the Basque Country: 85.7%
- Duero: 78.6%
- Tagus (Tajo): 69.7%
- Guadiana: 79.4%
- Tinto, Odiel and Piedras: 79.5%
- Guadalete-Barbate: 82.9%
- Guadalquivir: 80.4%
- Andalusian Mediterranean Basin: 73.0%
- Segura: 57.2%
- Júcar: 62.4%
- Ebro: 74.8%
- Internal Basins of Catalonia: 87.9%
Although storage levels vary significantly by region, no major river basin is currently experiencing critical water shortages.
Segura Basin Remains the Most Vulnerable
As in previous years, the Segura River Basin continues to have the country’s lowest reservoir level at 57.2% of capacity.
Even so, this figure is considerably higher than those recorded during Spain’s most severe drought periods over the past decade.
Current reserves are sufficient to meet urban supply needs, although future conditions will largely depend on rainfall during the remainder of the summer.
The Júcar Basin and Galicia Costa also remain below the national average but continue to maintain adequate water availability.
Spain Has More Water Than Last Year
One of the most encouraging aspects of the latest report is the comparison with previous years.
Spain’s reservoirs currently contain 3,119 hm³ more water than they did at the same time last year, reflecting the recovery made possible by abundant rainfall during autumn, winter, and spring.
Water reserves also exceed the 10-year average by 9,645 hm³, highlighting the significant improvement following several years marked by prolonged drought conditions.
These higher reserve levels provide greater security for drinking water supplies, agricultural irrigation, hydroelectric generation, and environmental conservation.
Summer Weather Will Determine the Trend
Although reservoir declines are expected during July and August, the pace of water loss will depend largely on weather conditions over the coming weeks.
If hot temperatures persist and rainfall remains scarce, particularly across Mediterranean regions, reservoir levels are likely to continue falling throughout the remainder of the summer.
Conversely, late-summer rainfall could slow the decline and allow many river basins to finish the season with storage levels well above those recorded in recent years.
For now, Spain enters the peak summer period with water reserves in a much healthier position than during previous drought episodes. Despite losing more than 1,000 hm³ in a single week, the country’s reservoirs continue to provide a solid supply of water, offering reassurance for households, agriculture, and industry while authorities continue to monitor weather patterns and consumption trends closely.
