The once abundant resource of potable water in north and central Portugal is under pressure from the combined exigencies of industrial and commercial activity - especially in the mining and “quality” tourism sectors.

It follows that it will be necessary for the construction of affordable housing and the provision of adequate social services for participating Portuguese citizens, immigrants and foreign guest workers alike. Their presence is vital if such expansion is to be achieved in conjunction with the creation of a future homeland where the traditions of civilized living may continue for the entire populace.

Unfortunately, the drought which has afflicted these regions for most of the 21st century shows no sign of abating and, if the warnings of climatic instability ring true, it will probably will be intensified as such projected investment comes to fruition with an inevitable demand for increased energy.

The essential need for conservation of water resources is of the utmost priority. Nearly all of the river basins rise in Spain where diversionary schemes to supply local needs will reduce the flow into Portuguese territory. In both countries, there is opposition to the building of new barrages due to the environmental upheaval caused.

The largest of such dams in central Portugal is that of Castelo do Bode which was inaugurated in 1951 after a problematic, enforced clearance of people from the abandoned banks of the river Zêzere without the payment of adequate compensation for the loss of their land and property. The concrete structure has a height of 115 m. and represses a usable capacity of nine hundred million m3. Most of this was destined for the production of electricity with installed power of 160 MW and for a water supply to Lisbon via an aqueduct of 135 km. Of course, water was also distributed to domestic and agricultural consumers in the central region and there was initiated extensive fishing in the picturesque lake so formed. Initially, tourism was the last priority but the building of hotels and watersports centres has grown apace in the past thirty years.

The pristine waters of the ACB have largely been kept free of pollution by strict building controls which insist on septic tanks being a minimum of 35 m. from the highest water level. Water taken by pump to dwellings must be treated by filtration before human consumption. However, the clandestine dumping of solid waste has always posed a problem and the recent expansion in the use of water-craft for leisure has increased the amount of flotsam and jetsam.


The drought of 1991 to 1995 in mainland Portugal forced upon national agencies and municipalities the urgency of introducing improved measures for the management of water resources by creating a National Water Authority which implemented a monitoring system. In 1998 a Convention was signed between Spain and Portugal. This created transboundary regulations to control the shared flow of water and to allocate more fairly the distribution within regions.

The drought of 2004 to 2006 was recorded as being the most severe since 1960 and forcibly illustrated the necessity for efficient international management. A new Commission was set up and produced a comprehensive report which concluded by making sensible and practicable recommendations for the planning of relief and conservation measures. Sadly, successive governments have failed to implement most of these findings with the result that we drift from crisis to crisis while rainfall lessens and average temperatures increase.

The covetous pleas from municipalities in the Algarve and Alentejo regions for water to be pumped through a grid of pipelines from the north to southern reservoirs have little bearing on reality. Instead, these bodies should heed the advice of the now disbanded Commission by (1) reducing consumption and (2) following the Spanish example of exploiting proven desalination processes. In order to benefit from such relief, it is vital to stabilize and gradually reduce numbers by confining agricultural and industrial products to those with the least water-intensive needs and, above all, by making hedonistic tourism a singularly selective and environmentally-friendly source of profit for the benefit of local communities.

by Roberto Cavaleiro

Tomar, 02 January, 2025