Algarve's Water Storage Surges Above Average as Hydrological Year Begins

The Algarve has kicked off the 2025/26 hydrological year with water storage volumes above average in all regional dams, except for the Bravura dam.

According to the latest data from the National Water Resources Information System (SNIRH), dated September 29 (the hydrological year started on October 1), the Odelouca and Odeleite dams—the two largest in the region, both intended for human supply—were at 75.8% and 75.1% capacity, respectively. This marks a significant increase from the previous year, when they stood at 34% and 30.4%. For average comparisons, only Odeleite has an established mean of 59.6% for September, as no average values exist for Odelouca.

Other dams, including Beliche, Funcho, and Arade, also show higher levels: 67.2%, 78.5%, and 45.3%, respectively. These figures are up from last year's 25.3%, 34%, and 18.3%, and exceed the September averages of 50.5%, 45.3%, and 22.2%.

Only the Bravura dam, at 45.3% capacity at the end of last month, falls below its September average of 51.5%. However, it still holds substantially more water than a year ago, when it was at just 18.3%.

Nationally, water storage decreased across all river basins, yet most remain above their historical averages. Excluding the Ribeiras do Algarve basin, which includes only the Bravura dam, the Mira, Ave, and Mondego basins are also below average.

Out of the 60 monitored reservoirs, 10 have water availability exceeding 80% of total volume, while five are below 40%. The Guadiana and Cávado basins lead with the highest volumes at 82% and 75.5%, followed by Douro (74%), Tejo (72.6%), Arade (72.7%), Oeste (72.4%), and Lima (58.2%).

At the end of September, the Ribeiras do Algarve basin had the lowest water quantity at 45.3%, trailed by Sado (46.8%), Ave (48.3%), Mira (53.4%), and Mondego (57%).

According to the Portuguese Institute of the Sea and Atmosphere (IPMA), total precipitation in September was below normal, amounting to about 60% of the average for the 1991-2020 reference period.

Author: Hugo Rodrigues with Lusa