The Mequinenza (Aragon) reservoirs, in the image above – the largest in the Ebro basin –, Riba-roja and Flix, already in the Catalan section of the river, opened their floodgates yesterday for six hours. The good condition of this swamp system, with Mequinenza at 83% of its capacity at the time of starting to release the water, has allowed the Ebro Hydrographic Confederation (Ministry for the Ecological Transition) to carry out a “controlled flood in the Bajo Ebro” that last year the drought prevented and that “is part of the ecological flow regime of the Bajo Ebro defined in the hydrological plan.”
It is part of the ecological flow regime defined in the hydrological plan of the central government and has “the objective of renaturalizing the flow regime, reducing the invasion of macrophytes and actively contributing to the study of sedimentary transit,” added the CHE, an organization that depends on the Ministry for the Ecological Transition, in a statement.
The discharge also allows us to gain space in the Mequinenza reservoir in the face of the foreseeable arrival of more water, in a situation that has nothing to do with last summer, when it was at 35% capacity. The rains of recent months in Aragon, Navarra and the Basque Country, Ebro above, guarantee drinking water in almost the entire province of Tarragona, with Mequinenza as a great reference, thanks to the mini-transfer from the Ebro to Tarragona.
The rains of recent months upstream, in Aragon, Navarra and the Basque Country, explain the good condition of the Mequinenza, Riba-roja and Flix reservoirs, which form a single water reserve system.
The floodgates in Mequinenza opened at eight in the morning and continued releasing water until two in the afternoon. Mequinenza is the large reservoir of the Ebro River, the one with the greatest capacity, and is key to the supply of drinking water for a large part of the Tarragona district.
The operation contributes to the ecological flow in the final stretch of the Ebro River until it reaches the mouth, in the Ebro delta, one of the historical demands of environmentalists.
The flows increased yesterday until they reached a flow of 1,400 m3/s at 9:00 in Mequinenza and Riba-roja and 9:30 in Flix. The flood continued until 2:00 p.m., at which point the Mequinenza dam closed the floodgates, releasing the exploitation flow of 600 m3/s again.
The flood is already noticeable downstream. In Tortosa the flow went from just under 200 m3/s on Monday to exceeding 800 m3/s yesterday Tuesday night, according to CHE data.