eucalyptus trees

Bravura dam ‘crisis’ almost certainly linked to thirsty hectares of eucalyptus

Are desalination plants the answer for Algarve? Could different approach fix Algarve’s chronic water problems?

At a point where political leaders seem intent on spending millions of euros of European money on desalination plants to solve southern Portugal’s water shortages, very little has been discussed about ‘better land management’ and/ or the opinions of experts.

PAS (the platform for sustainable water) set out its arguments against desalination well over a year ago, advocating sustainable solutions that they claimed at the time were “not (being) taken into account”.

PAS’ main points – beyond the ‘negative effects’ of the desalination process – were that it could be being used as a vehicle for private companies to make a great deal of money.

PSD Algarve has picked up on this point particularly, demanding ‘full transparency’ regarding the construction process, as well as the many uncertainties and doubts.

And into the maelstrom come soundbites seemingly amplifying the ‘dire situation’, as often reported by our own paper.

Bravura dam – Photo: Nuno de Santos Loureiro

But has anyone looked into why, for example, the Algarve’s Barragem da Bravura remains so critically low in spite of pretty impressive rainfall through December and January?

The answer is yes, but again it hasn’t been widely publicised.

Stephen Hugman has a master’s degree in Water Resources Management; he leads the ‘A Nossa Terra’ environmental association that has led various ‘battles’ (often  successfully) and he lives in Monchique, very close to the still critically low dam.

He has set out almost certainly what the problem is – and how it can be fixed.

His paper for Europe Direct Algarve was written in Portuguese, but for English-speakers it makes fascinating reading:

“Since the 1995 drought, Monchique municipality, with the support of European Union funding, has implemented a series of projects to ensure the availability of groundwater to supply the populations of Monchique, Marmelete and Alferce”, he explains. 

“At the end of the 1990s, a dam was built in Cruz da Fóia to retain winter flows and allow greater infiltration into the aquifer that supplies the village of Monchique. 

“Recently, a channel and infiltration system was built to another aquifer in the system through the SOWAMO project. This project included the removal of an intensive eucalyptus plantation. 

(Also) “recently, the council removed a eucalyptus plantation upstream of a third aquifer. 

“These actions contributed to making more water available to supply the municipality. 

“Could this type of management of land use in hydrographic basins contribute to resolving the lack of water in the Algarve and Alentejo?

As Stephen Hugman explains, the Bravura dam was designed almost 70 years ago, using available rainwater at the time.

“Since then, average annual rainfall has decreased (particularly from January to March) and 71% of its watershed (meaning the area that drains into the dam) has been intensively planted with fast-growing trees for the industrial production of pulp for export. 

“Could this new use of soil have contributed to the reduction of flows in streams, especially during the rainless summer months?”

The answer is almost certainly yes. Eucalyptus trees are known to absorb a large amount of water as well as nutrients from the soil, and not to ‘share’ well with the rest of the ecosystem.

But Stephen Hugman doesn’t say this. He simply puts up an example to his questions:

“A better known example is from Cape Town in South Africa. For years, the city has had a programme to control invasive alien trees, such as acacias and eucalyptus. It is estimated that for each hectare cleared of these invasive species, an average of 1840 m3 of additional water is obtained per year. The climate in Cape Town is similar to the climate in the Algarve. If this value is applicable to the hydrographic basin of the Bravura Dam, the additional annual flow will be around 10x 10m3/year. This flow is sufficient to double the current volume in the dam’s reservoir and will allow the use of water for irrigation. A study of the specific conditions in the Algarve will be able to determine the real value”.  

His text: “Water, Invasive species and Europe” even goes as far as to suggest that dam operators in the Algarve/ Alentejo could compensate landowners in the hydrographic basins of their dams for producing water through the control of invasive alien species of rapid growth and promoting a ‘more rational use of the soil’.

But we don’t hear views like this predominantly.

We hear how ‘now is the time to move on desalination’ (due to so many millions of euros coming through from Brussels); how now is the time in fact to ‘increase capacity’ originally forecast, potentially meaning plants in both Albufeira and Lagos areas – without having any information on which companies may end up running the plants, or how even consumers will be charged for the use of water produced by them.

And that is before the ‘downsides of desalination’ are aired, or details given on how they may be mitigated.

Thus the time is for ‘public participation’.

Various parties are preparing submissions for the exercise, already open on the Public Participation portal and remaining active until March 15. The Resident will be following these up as they come in.

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