Water as a scarce commodity

Water is a scarce commodity and essential to life, a design of Humanity, through SDG 6 of the United Nations. Concerns about its rational use should be part of our daily lives, but in times of drought like we are experiencing now, they should naturally be redoubled.

And do we have much or little water in Portugal? The “Assessment of current and future water availability and application of the WEI+ scarcity index” was recently presented by the APA. As main conclusions it can be drawn that: there have been no wet years since 2000, which allowed filling the reservoirs and recharge the aquifers; in the last 20 years precipitation has decreased by about 15%, and it is expected that it will decrease by between 10 and 25% by the end of the century; in the last 20 years the availability of water has reduced by about 20%; scarcity is extreme in Mira, severe in Sado, Guadiana, Ribeiras do Algarve and Oeste, high in Vouga, Liz, Cávado and Tejo, and low in Minho, Douro and Lima. Naturally, this scarcity is aggravated in periods of drought, as we are now experiencing, not only in urban consumption (13%), but especially in agriculture (70%) and also in other uses, such as the production of thermoelectric energy, industry, livestock , on golf, etc.

The water services we have today

Around 250 municipal, state and private management entities provide services to almost 10 million inhabitants. For this, we have invested 13 billion euros over the last 25 to 30 years and created excellent water services. In fact, in 1993 only 81% of households in mainland Portugal were covered by the public water supply service, currently reaching 96%, with a growth factor of 1.2. With regard to water quality, in 1993 only 50% of households had safe water, in accordance with national and European legislation, currently reaching 99%, with a growth factor of 2.0. In 1993, only 31% of households were covered by public wastewater management services with collection and treatment, currently reaching 86%, with a growth factor of 2.8.

What are our water systems today? Around 820 Mm3/year of surface and underground water are captured to supply the population, and for that we use an enormous heritage of 119,000 km of pipelines, 250 surface abstractions, 5900 underground abstractions, 220 treatment stations, 2400 pumping stations and 8900 reservoirs. We need a new heritage management culture, so that we can take all the added value of this infrastructure in the short, medium and long term, and be able to pass it on in good conditions to the next generation.

Water services in a situation of scarcity

And now, with the drought, what to do about water services? We have to act simultaneously on the supply side and on the demand side.

On the supply side, responsible authorities and water service providers should: look for complementary conventional, surface and underground sources and study the feasibility of non-conventional sources such as desalinating sea water, making better use of rainwater and, for less noble uses , reuse wastewater.

On the demand side, the responsible authorities and water service providers must: raise public awareness of the need to reduce consumption; increase the water efficiency of services by reducing losses in the production process and distribution systems; establish a ban on non-essential uses, such as washing streets, public areas and containers, watering gardens and green spaces, filling new pools, decorative fountains, etc.; and using economic incentives such as increasing the water resources fee and even increasing the highest tariff levels.

Portugal took the good decision in the past to set up a Permanent Commission for the Prevention, Monitoring and Accompaniment of the Effects of Drought, which is responsible for defining guidelines of a political nature within the scope of this adverse climate phenomenon. And that it has been honorably doing its job.

The question is whether we want, as a society, to act on a case-by-case basis due to scarcity and the pressure of events, as is often the case, or if we prefer to act in a planned manner from a perspective of sustainability. And the answer to this question will necessarily mark the pace of development of the sector and the country.