Odelouca dam

Water in the Algarve

There is a common notion that the Algarve is suffering from drought. Indeed, the measure of rainfall this winter at 150mm just before this present downpour is much lower than the next lowest, 500mm in 2005.

Since 2010, the recorded annual rainfall has been lower than the annual average.

The word ‘drought’ is one that perhaps needs some investigation – what precisely is a drought? The Algarve has lived through many similar dry spells and Algarvians used to adapt with resilience. Six years of the decade of the 1870s were especially dry; the 1940s were also challenging; and from historical observations we even know of the shortages of 1189 and 1217-20. For those people, drought led to the slaughter of livestock, the destruction of harvests and potential starvation. In those days, drought was life threatening.

From the 1960s, as many artesian wells have been drilled and dams have been constructed, the dreadful consequences of drought have practically disappeared. Today, most people are as yet unaffected. Thanks to these new sources of supply, farms and gardens are now irrigated, and our consumption of domestic water has grown.

Unlike our ancestors, we use a scarce and finite resource on a daily basis as if it were inexhaustible. The Odelouca dam, with a capacity of 134 million cubic metres, came on stream in 2009, and it was then believed that the Algarve had become immune to drought. Built with the promise of ending the threat of drought in the Algarve, the dams of Funcho, Beliche, Odeleite as well as Odelouca are now practically empty. And so we are now draining the aquifer, which allows us to continue spending water even though we have no rain.

The irregular nature of rainfall is one of the characteristics of the Mediterranean climate and it is clear that climate change is making rainfall even more irregular, and extreme weather events more likely. Above average temperatures are evident in the different seasons of the year, particularly in the summer, causing fires such as those in the Serra de Monchique (2003 and 2018), Caldeirão (2004) and Serra de Tavira (2012).

Humans tend to react only when faced with a crisis and just as according to the Algarvian proverb “we remember Santa Barbara only when it thunders”, so recently the mayors and councils of the Algarve, in the middle of our current drought, decided that it is time to take drought reduction measures.

The mayors even made a tour of Spain, with a view to researching the provision of expensive desalination plants in the Algarve, while at the same time stressing the urgency of building the Foupana dam in Alcoutim.

What about the dams which already exist? In their returns to ERSAR (water supply entity), the Algarve councils show how much water has been lost in their pipelines and is never, therefore, invoiced and paid for. At the good end, Tavira and Faro lose only 16.6% and 18.3% of their water respectively; at the other end of the scale, Silves loses 50% and São Brás a whopping 55,1%. There are existing distribution networks in the region which are more than 50 years old and need to be replaced.

If there is no rain, it doesn’t matter if you have five, six, or seven dams, there will still be a shortage of water. Hotter summers can also lead to eutrophication of the water (contamination by too many nutrients such as fertilisers) in the dams, making the remaining water useless. While it was sensible to build dams in the 1970s, our current circumstance demands not a greater volume of water but better management of this precious resource.

Let us not destroy yet another mountain valley in order to store more water which we will then waste with excessive irrigation and faulty pipework. While the strategy to combat drought must impact on everyone in the Algarve, the municipalities and water management companies must take the lead in the good management of water.

Further, recent fires have led to greater erosion of the already impoverished soils. Between São Marcos da Serra and Cachopo, there is a continuous patch of scrub. It is a tremendous fire hazard, and it is a mere matter of time before the terrible fires of 2004, 2012 and 2018 recur. It is urgent to re-afforest the Algarve mountains with drought-hardy native tree species because tree cover helps the ground to retain rainwater and helps to recharge the aquifers.

The Algarve Intermunicipal Community (AMAL) must urgently address these water issues and it is time for solidarity between the Câmaras of the coast and those of the hills. It seems fair that the richer and more populous coastal municipalities should pay for the re-afforestation and maintenance of the interior since the whole community of the Algarve will benefit. This action will not only reduce the impact of droughts, and help to replenish the aquifers, but it will also help to prevent fires.

The answer to the problems of drought in the Algarve lies not in expensive desalination plants, but in the proper management of the Algarve countryside and the water distribution pipework.

This piece is based on an article by the environmental engineer Aurélio Nuno Cabrita, which appeared in Sul Informação on March 8, 2020

By Lynne Booker
|| features@algarveresident.com

Lynne Booker, along with her husband Peter, founded the Algarve History Association. lynnebooker@sapo.pt
www.algarvehistoryassociation.com

Odelouca dam