Reservoir cleaning programme will boost next year’s available water supply
Portugal’s Environment Minister, João Matos Fernandes, has announced the way in which department will spend €3.5 million to increase the capacity of eight reservoirs. He also plans to refill the reservoir at Monte da Rocha where the water volume is down to 8% of capacity.
The Government spend, now that water levels are at historic lows, aims to improve the water quality so that more of the total volume in the reservoirs is useable.
The minister was visiting the treatment station at the almost dry Monte da Rocha dam, near Ourique, to launch his short-term cleaning work programme.
Cleaning reservoirs may sound like a Herculean and pointless task but the idea is to remove the organic matter that collects at the bottom of the reservoir, as the water low down currently may not safely be used for public supply.
“In reservoirs, there is always a proportion of water that we call dead volume, volume that is right at the bottom of the reservoir and where there are many nutrients and is extraordinarily difficult, expensive and complex, from the technical point of view to send this water for treatment and distribution,” explained Fernandes.
“These are not emergency measures to combat drought, because those have already been taken at the beginning and throughout the summer, but rather these are in preparation for the next season,” added Fernandes.
At the beginning of December 2017, the Mayor of Ourique, Marcelo Guerreiro, wrote to the Ministry of the Environment, stressing that “the country, the lower Alentejo and Ourique are confronted with a worrying situation of extreme drought that poses a set of risks and challenges to the supply of water for human consumption, the rational management of a natural resource fundamental to life and the use of this resource in the development of productive activities essential for our rural world and our local economies.”
Guerreiro added that the council has long demanded the linking of the Roxo dam to the Monte da Rocha reservoir to allow water from the massive Alqueva reservoir to reach Monte da Rocha in the lower Alentejo.
Ourique council said today that “the minister’s visit and announcements at the reservoir was a positive step in building sustainable future solutions for the supply and efficient use of water in the Ourique and lower Alentejo areas.”
The work will be carried out in three reservoirs in the Alentejo Hydrographic Region, three in the Tagus Hydrographic Region and two in the Northern Hydrographic Region.
In the Alentejo Hydrographic Region, interventions will be made at the Monte da Rocha (Ourique, Beja), Roxo (Aljustrel, Beja) and the north and east arms of Pego do Altar (Alcácer do Sal, Setúbal).
In the Tejo Hydrographic Region, the work will cover the Carvalhal Dam, that is, in the connection to the Albufeira (Portalegre) and the reservoirs of Póvoa and Meadas (Castelo de Vide, Portalegre) and Divor (Arraiolos, Évora ).
In the Northern Hydrographic Region, interventions will be made in the reservoirs of Pretarouca (Lamego, Viseu) and Penaireiro (Vila Flor, Bragança).
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