From Drought to Overflow: How Heavy Rains Transformed Portugal's Water Reservoirs

A Transformative Rainfall in Algarve

The once arid landscape of Algarve has become a vivid reminder of water scarcity in Portugal. With dried rivers and parched fields, the region faced historical lows in water capacity. However, the recent intense rains have significantly replenished these resources.

In March, rainfall levels in Algarve were more than double the 30-year average, while Alentejo saw three times the usual amount, largely due to storm Jana. Within a month, water reserves reached maximum levels, necessitating preventive discharges to avert structural risks. Now, Algarve has enough water storage for the next two years.

A Sigh of Relief for Algarve

The reservoirs in Algarve, which were at record lows, filled up remarkably fast. The Odeleite reservoir reached 94% capacity, and Beliche followed closely at 89%. Such levels haven’t been seen since 2018. All reservoirs across the country are now above 20% capacity. The focus has shifted from water scarcity to its management.

Teresa Fernandes, spokesperson for Águas do Algarve, stated, "This is a happy moment because Algarve's reservoirs are filling up, but we must remain vigilant as we don’t know when the next drought will hit."

Alqueva Reservoir's Abundant Supply

The Alqueva reservoir in Alentejo is also nearing its maximum storage capacity, ensuring water supply for at least three years. José Pedro Salema, president of the Alqueva development and infrastructure company, explained that the hydropower turbines can discharge 800 cubic meters per second, which is sufficient to maintain current levels.

Nationwide Impact of Heavy Rains

This situation isn’t limited to Algarve. Across Portugal, heavy rains have filled reservoirs to levels not seen in years. Out of 80 monitored reservoirs, 53 exceeded 80% capacity, with 12 reaching their limits. In Castelo de Bode, a major reservoir, safety discharges have commenced as it approaches maximum capacity, a situation that hasn’t occurred in a long time.

These rains not only support human water supply but also benefit agriculture and hydroelectric production, sectors that have struggled due to prolonged drought.

Challenges in Vale do Tejo

While the rains have been a boon for Algarve, they have posed challenges in the Vale do Tejo. Both Spanish and Portuguese reservoirs were forced to release large amounts of water, causing flooding in several areas and activating the Special Emergency Plan for Floods. In Santarém, roads and agricultural fields were submerged due to increased river flows from the rain and reservoir discharges.