Water stress occurs when the demand for water exceeds the available amount during a given period. The FAO has identified a gradually increasing trend in this situation globally over the past 20 years, with areas experiencing higher stress and regions where declining water availability cannot compensate for growing demand.
The Sustainable Development Goals of the 2030 Agenda dedicate Goal 6 to “Clean Water and Sanitation.” Among its targets, point 6.2 highlights that although water use efficiency has improved by 9%, water stress and scarcity remain global concerns.
Among the main causes are population growth and climate change. In this regard, the prevailing drought trend in Europe results in losses of around 9 billion euros annually. Research is moving rapidly to implement and develop water storage and optimization systems.
In Spain, nearly half of the stored water suffers from eutrophication issues, and about 11% of the total is lost through evaporation. To address these problems, the LIFE H2OLock project was created, aiming to improve the quality of natural water resources.
The project seeks to alleviate the pressure on water bodies and resources, and indirectly mitigate the impact of water stress, by covering medium and large-sized reservoirs with a versatile and cost-effective solution. The goal is to reduce evaporation by up to 80–85%, promoting the sustainable use of water and enhancing water resource availability.
Levels of Water Stress
The World Resources Institute has created a classification forecasting which countries will face the highest water stress by 2030 and 2040. Spain ranks 28th globally. The country’s water resource consumption ranges from 40% to 80%, but in some areas, it exceeds 100%.
The organization defines five levels based on the percentage of demand to be met. When the ratio is below 10%, it is considered low water stress; by contrast, extremely high stress is defined as over 80%.