Environmental Manager Chemical Civil Engineer of Universidad de Concepción Master's Degree in Management and Environmental Engineering of Universidad Politécnica de Cataluña, Barcelona, Spain.
January 9, 2021
The projection of water scarcity in our country for the period 2030-2060 forecasts a decrease in water availability of between 5% in the southern zone and 50% in the northern zone.
These are the results of the National Water Balance, which is the document used by the Directorate General of Water to assess water availability at national level, the latest update of which was carried out by experts from the University of Chile between October and December 2020.
The main factors influencing this decrease are the increase in user demand, changes in land use and climatic variations.
Regarding the latter factor, the largest temperature increases are concentrated in the centre and north of the country, with an increase of 0.4°C expected for the southern macro-zone, 0.5°C for the southern macro-zone and between 1 and 2.5°C for the central zone. In terms of rainfall, it is in the central-southern zone where the most significant decreases are projected, reaching a reduction of up to 25% in areas such as Petorca, which has been one of the symbols of the country’s water scarcity.
All the basins analysed in this study (58 basins in natural regime) project a decrease in average annual flow (on average -25%, the most unfavourable, and -10% the most favourable), with the mountainous areas showing the most significant change.
Although almost all catchments have seen a decrease in average precipitation of 29%, this is not the only factor explaining the change in the catchments. The change in land use due to the expansion of the agricultural industry in the central zone has led to a large increase in water consumption. On the other hand, water rights are inheritable and not expropriable, so there is a growing demand and supply of water, the natural projection of which indicates a lower availability in the future.
Although the data presented are projections, which could be more accurate by improving existing measurement systems, they present a clear trend with a clear negative impact for our country. What can we do about it? How will we face this scenario?
Source: National Water Balance