According to data from the National Water Resources Information System (SNIRH), the most serious situation in August was in the Algarve, in the Barlavento watershed, which had less than 10 percent of its stored volume according to a report by Diário de Notícias.

The Tagus basin, the largest nationally in terms of occupied surface, now has a storage below 50% for the first time since October last year, the month in which the oldest data from the SNIRH are available.

In the latest data provided by this entity, the Douro basin - which, like the Tagus, is shared with Spain - is also at its lowest level since October last year (51% of storage volume).

At the end of July, of the 59 reservoirs monitored by the SNIRH, only six had a water volume above 80%, with 26 being below 40%, including the Campilhas Dam (3.6%, located in the Sado basin), Paradela (9.5%, in the Cávado basin) and Bravura (11.4%, in the Barlavento basin), being the three dams in the worst situation at national level, according to data from the Agrometeorological and Hydrological Monitoring management report.

A month later, in August, "storages by watershed" were lower than the storage averages over the 30 years, from 1990/91 to 2020/21.