Segura reservoirs reach 30% of their capacity for the first time in three years

For the first time in three years, the Segura River basin’s reservoirs have reached more than 30% capacity. The recurrent Atlantic storms of December 2025, particularly in January, had a substantial impact on the basin’s higher reaches, including the Alcaraz, Las Villas, Cazorla, and Segura mountain ranges, raising reserves by 46 cubic hectometres in the penultimate week alone. However, the Segura River basin continues to be—and has historically been—the Spanish river basin with the lowest volume of stored water in relation to its capacity year after year.

Above average

However, the rains and snowfalls that have soaked the soil in most of Spain have offered some respite from a chronic water deficit, as well as a winter landscape with snowfall in huge portions of Murcia, Granada, and the southeast.

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The basin now stores 354 cubic hectometres of water, which is 31% of its capacity. This level has not been reached since February 2023, and it is already higher than the average reserve level for the same week of the year during the prior decade, which is 29%.

These reserves ensure water releases for irrigating the traditional farmland of the Vega Baja region, which has been irrigated directly with water from the Segura River for centuries, as well as the supplementary use of surplus water by the Camp d’Elx area and the communities along the entire left bank of the river in the province of Alicante. However, in the absence of a release commission that could rule otherwise, these reserves do not permit the violation of present irrigation limitations. Among the reservoirs that have improved the most, despite their hazardous position, is the Cenajo Reservoir, the basin’s principal water resource infrastructure, which now stores 103 cubic hectometres, or 23% of its 437 cubic hectometre capacity. Last year, it only had 87 cubic hectometres.

Through water transfer

The intricacy of the Segura River basin, where the total amount of water stored is also greatly affected by the Tagus River transfer system, necessitates that the aqueduct’s contributions be considered in the final balance. This is because some reservoirs in the basin, like La Pedrera, Crevillent, and El Talave, only receive transferred water, the first of which comes from the Torrevieja desalination plant.

These reservoirs, which are generally only used to manage and distribute water from the Tagus River, are sustaining higher-than-normal water levels thanks to one of the most generous series of water transfers in recent years. This is especially true in the second half of 2025, when monthly authorisations of 60 cubic hectometres coincide with abnormally large winter rainfall and lower water demand in citrus-growing areas, thereby keeping reservoir water supply at a minimum.

The reservoir

La Pedrera, Alicante’s most important reservoir, is currently at more than 25% capacity, storing 65 cubic hectometres. This reservoir is too large for its current use. Initially, Alicante, Murcia, and Almería were expected to get 1,000 cubic hectometres each year, but this was eventually decreased to 600.

The average yearly flow for the 46 years of operation of the Tajo-Segura Water Transfer has been 330 cubic hectometres, implying that La Pedrera reservoir has only exceeded 40% of its capacity a few times. It was only filled to capacity for testing in the 1979-1980 hydrological year. Since then, it has never exceeded 65% of its 246 cubic hectometre capacity.

Rainy January

According to AEMET statistics, all of the peninsula’s hydrographic demarcations are now at or over 50% capacity, and the soils of some sections of western Andalusia, Galicia, Extremadura, and the two plateaus are saturated with rainwater following the rainiest January in the last 25 years.

However, this saturation has only had an indirect impact on the Segura River basin. However, the rains and snowfalls in the upper reaches have allowed, for example, the spring of the Segura River to reappear in the town of Santiago Pontones in Jaén province, which had been dry for many months, and the source of the Mundo River, the Segura’s main tributary and normally with a greater flow than the Segura itself, to flow in all its splendour once more in the Albacete municipality of Riopar. They have also given the dryland areas of the province a more spring-like aspect in terms of vegetation.

Improved data for Beniarrés reservoir in the Júcar basin

The Júcar River basin in central and northern Alicante province, including the Vinalopó River valleys, has a significantly better overall position compared to the Segura River basin. However, the situation is less favourable for the reservoirs located in Alicante province: Amadorio, Guadalest, and Beniarrés. The Júcar basin is at 53% full, but the Amadorio reservoir barely holds four of its 16 cubic metres and Guadalest four of its 13. Only the Beniarrés reservoir, which gathers water from the Serpis River, has improved, storing ten cubic hectometres: it is at 37% full, up from just over 20% the same week last year.