The Center for Research, Development, and Innovation for Comprehensive Water Management in Arid Regions (Cigiaa) presented its 4th Situation Report, titled “Hydrological and Socioeconomic Drought in the province of San Juan: 5 key points in water management”, where the critical scenario that the province is going through due to the structural decrease in the water supply is accurately described.
The sustained lack of snow in the upper basins of the San Juan and Jáchal rivers, below the average of the last 25 years, validates scientific projections that have been warning about the decline in snowfall in the Central Andes since the beginning of the century.
“We need to start taking action now because the situation is critical,” stated Facundo Vita Serman, director of Cigiaa, in an interview with Diario Huarpe.
Sustained decrease in flow and deterioration of water systems
The report reveals that:
- The historical flow of the San Juan River, estimated at 1,900 hm³, has fallen to 1,544 hm³
- In the last decade, the average annual contribution was 1,042 hm³, barely 50% of the historical value
- Other factors include:
- Glacier retreat
- Rise of the 0 ºC isotherm
- Drop in water tables
- Salinization and contamination of aquifers
From hydrological drought to socio-economic emergency
Cigiaa warns that San Juan is no longer facing only a hydrological drought but a socio-economic drought, whose impacts affect:
- The provision of drinking water
- Agricultural productivity
- Hydroelectric generation
- The ecosystem balance of the arid territory
The Scientific Advisory Council of Cigiaa, composed of INTA, INA-CRAS, Conae, the National University of San Juan, and the provincial government, identified five critical elements:
- Dams at structural risk, with levels below safety thresholds
- Decline and contamination of aquifers due to overexploitation
- Risk in the provision of drinking water, especially in the Tulum Valley
- Interruption of the flow of the San Juan River, hindering aquifer recharge
- Extended cuts in the irrigation network, with a strong impact on agriculture
Towards an integrated and multisectoral management
Although the decision of the provincial Executive to allocate 800 hm³ to the irrigation system for the 2024/25 season improved surface reserves, the pressure on aquifers continues. The current model of supply-based management, with an efficiency below 20% in gravity irrigation, is considered unsustainable.
Cigiaa proposes moving towards a model of Integrated Water Resources Management (IWRM), based on:
- Rational use of water
- Priority for human consumption
- Watershed planning
- Social equity
- Participatory, multisectoral, and territorial approach
“The key is to recognize water as a strategic, scarce, and public resource, whose conservation and use must respond to scientific, technical, and social criteria,” concludes the report.
