Of the 60 monitored reservoirs, 35 had water availability greater than 80% of the total volume and six less than 40%.

The Barlavento Algarve basin, with 13.3%, had at the end of April the lowest amount of stored water, globally, as has been the case for over a year.

The average storage for the month of April in the Barlavento basin is 76.5%, according to SNIRH.

With less water availability were also the Mira (35.7%) and Arade (39.6%) basins.

The basins of Ave (86.9%), Tejo (86.1%), Douro (85.2%), Mondego (83.5%), Cávado (83.3%), Lima (82.2% ), Guadiana (81%), Oeste (77.2%) and Sado (60.1%) had the highest levels.

The April 2023 storages by river basin were higher than the April storage averages (1990/91 to 2021/22), except for the Mondego, Sado, Guadiana, Mira, Ribeiras do Algarve and Arade basins.

Each hydrographic basin can correspond to more than one reservoir.