Reservoir photography is back in motion this week. with a summer adjustment: More consumption and evaporation reduce stocks. Even so, The peninsular reserve remains at high levels for these dates, a starting point that positively influences water management.
The panorama is not uniform across the map: There are basins that are still under stress, others that are consolidating, and territories with specific measures. Meanwhile, the hydrological year has seen above-average rainfall. y The prolonged drought persists only in a tiny fraction of the territory.
X-ray of the reserve in Spain
The total reservoir water reserve stands at 65,8% after a weekly drop of 692 hm³ (–1,2 points). Despite the adjustment, the current level is almost nine points higher than that of a year ago. and is more than 12 points above the average for the last decade.
Hydroelectric reservoirs are at 79,2% of their capacitya 0,9 point drop in the week. On the other hand, those for consumptive use - intended for human consumption and agriculture - are located in the 59,8% (–1,4 points and –542 hm³ compared to the previous week).
In absolute values, the consumption reservoirs total 23.199 hm³, clearly above the same dates last year and the ten-year average. The distribution, however, is very uneven between demarcations.
In meteorological terms, the hydrological course accumulates 645 l/m² until the beginning of August, around a 12% above the average for these dates, with marked surpluses in areas on the Mediterranean coast and in the southwest of the peninsula.
The prolonged drought is reduced to 0,2% of the peninsula's surface area., according to MITECO, although situations of temporary shortages persist: Nearly 5% of the territory is in emergency or alert situations due to difficulties in meeting demand.
The most stressed basins continue to be the Segura (28,6%) and Guadalete-Barbate (47,5%)., along with the Guadalquivir (around 50%) and the Andalusian Mediterranean Basin (51,6%). On the positive side, the internal basins of the Basque Country (85,7%) and the Miño-Sil (79,3%) stand out..
In the Guadalquivir, the Hydrographic Confederation places the basin at 49,28% of its capacity (8.034 hm³). By province, Huelva leads with 93,45%, followed by Seville (75,45%), Córdoba (48,81%), Jaén (40,50%) and Granada (28,80%)..
The national inventory totals 374 reservoirs with a capacity of 56.000 hm³., approximately half of the country's river flow. New dams have recently been added, such as Irueña (Duero) and La Colada (Guadiana), and nine exceed 1.000 hm³; La Serena (3.219 hm³) and Alcántara (3.160 hm³) top the list.
Some reservoirs act as flood control systems and often appear with very low levels., such as Valdeinfierno (Segura) or the Algar dam, designed for flood protection rather than for sustained storage.
Canary Islands: Dams at their limit
Intense heat and low rainfall have brought several dams in Gran Canaria to critical levels., with numerous reservoirs that do not even reach 1% of their capacity.
The Ayagaures dam, with a total volume of 2 hm³, only stores about 9.000 m³., less than 1%. Chira, the second largest on the island, is also around 1%. and would have lost around 58.000 m³ in one year.
Gambuesa reflects the same trend, with a volume almost halved compared to the previous year.The combination of heat, lack of precipitation and summer demand It compromises the resource and requires intensifying management at the island level..
Valencian Community: normality in the CHJ
The Júcar Hydrographic Confederation reports a 56% total filling rate., more than 10 points above August of last year. Only the Marina Baixa system remains on alert., with levels around 25%.
A year ago, emergencies and drought alerts coexisted. in several systems (Sénia-Maestrat, Palancia-Los Valles, Marina Alta and Marina Baixa, among others). This summer, the map improves: Marina Baixa remains on alert and Serpis and Vinalopó-Alacantà remain on pre-alert, but with progress compared to 2024.
The improvements in specific reservoirs are notableUlldecona falls from nearly 82% empty; Regajo increases its capacity; Sichar and Arenós double their capacity; and Forata reaches nearly 69% after last fall's torrential rains. Cortes de Pallás remains stable, and La Muela and El Naranjero increase.
Catalonia and Galicia: recovery and surveillance
In Catalonia, recent rains have allowed reserves to increase significantly. and the inland basins remain at around 76-77% of their capacity, clearly above the threshold that defines drought scenarios.
The Ter-Llobregat system shows unusual stability in the middle of summer.: : Sau stands out for its rise of around four tenths (≈65%), with minimal decreases in La Baells (≈89,8%), Susqueda (≈81,2%) and Darnius Boadella (≈66,2%). La Llosa del Cavall remains very stable (≈84,1%)Sant Ponç is slightly improving, while Riudecanyes, with 36,8%, remains a weak point alongside Siurana.
In Galicia, the Xunta activates the pre-alert for moderate shortages in the Lérez River (Pontevedra) and Grande River–Camariñas Estuary–Costa da Coruña systems up to the Anllóns, with savings recommendations for around twenty municipalities and equivalent measures in the Baiona subsystem.
The reservoirs in Galicia-Coast are 84,32% full., 7,9% less than a year ago but only 1,74% below the ten-year average. The decrease in flow rates since mid-July, the expected dry weather and the summer population increase justify the reinforcement of surveillance..
With summer still ahead, high reserves nationwide, sharp contrasts between basins, and the situation in the Canary Islands and other territories show an uneven trend that requires continued moderation of consumption, taking advantage of every rainy episode, and maintaining adequate planning to face the second part of the season.