Data from the provincial water system show that agricultural use accounts for the highest demand and that the real deficit lies in management and infrastructure. For example, only a minimal percentage of the canal network is lined.
By Panorama Minero
Every time mining development returns to the spotlight in Mendoza, water becomes the central axis of public debate. In this context, various sectors insist on linking mining activity to a direct risk to water resources. However, the available technical data—of institutional origin and presented in specialized forums—describe a very different scenario: for decades, most of the province’s water has been used by agriculture, under irrigation systems burdened by structural deficits in infrastructure and management, entirely independent of mining development.
This snapshot was presented by Walter José Barchiesi during the talk “Water infrastructure works to increase efficiency,” held as part of the 5th International Congress Water for the Future, a technical event organized by the General Department of Irrigation.
Mendoza is an arid province that built its productive matrix on artificial irrigation. To sustain this model, it relies on a water network of nearly 15,000 kilometers of canals, developed over more than a century. The critical fact is that only 14% of this network is lined, while the rest consists of earthen canals, with significant losses due to infiltration and evaporation before the water reaches the farm.
This structural condition explains much of the system’s historical inefficiencies. Even in scenarios of good on-farm management, a substantial fraction of water is lost upstream during conveyance, making it clear that the core problem lies not only in final water use, but also in the infrastructure that transports it.
Irrigation Systems: Predominance of gravity irrigation and limits to technological change
According to data from the 2018 National Agricultural Census, 68% of irrigation in Mendoza is gravity-based, 24% belongs to localized irrigation, barely 2% to sprinkler systems, while the remainder is distributed among other systems or undifferentiated surfaces. This configuration responds to topographic, economic, and energy conditions that continue to constrain the system’s capacity for transformation.
The technical analysis presented warns that switching systems is limited by high direct and indirect costs. In many cases, moving to pressurized irrigation involves high per-hectare investments, higher energy costs, and greater maintenance requirements—factors that explain why gravity irrigation remains dominant, even in contexts of water scarcity.
Irrigation Management: The greatest savings potential lies in management
One of the most relevant contributions of the presentation was the quantification of the impact of irrigation management, even without changing the system used. In surface irrigation, the main savings factors identified were reducing irrigation time, accounting for 31% of savings; correcting land levels through leveling, at 18%; and infrastructure improvements, at 11%, complemented by adjustments in unit flow and crop management practices.
These changes allow water consumption reductions ranging from 30% to 70%, depending on the crop and initial conditions, without affecting productive yields—an essential fact in a province where the discussion often focuses on how much water is used rather than how it is managed.
The data presented included concrete examples from farms with optimized surface irrigation. In these cases, comparisons between current and optimized irrigation showed consumption reductions of up to 70%, accompanied by significant economic savings. In absolute terms, savings ranged from approximately $21,000 per hectare per year in already relatively efficient farms, to more than $1.8 million per hectare per year in critical situations, clearly demonstrating that water inefficiency is also economic inefficiency.
These figures provide relevant insight for any resource-intensive activity, including mining: improving efficiency not only preserves water, but also reduces structural costs.
Water Footprint: Water does not disappear
Another topic addressed was the water footprint of food. According to FAO data, 70% of water used worldwide is associated with food production. In this context, an illustrative example was presented: producing 30,000 kilograms of potatoes requires 6.5 million liters of irrigation water, of which only 25,000 liters are incorporated into the final product, while the rest returns to the hydrological cycle through evapotranspiration.
This does not eliminate the need for efficiency, but it provides a key technical clarification: agricultural water is not irreversibly consumed, but rather fulfills a productive function within the system—an aspect often absent from public debate.
Within this framework, the data help put the mining-and-water debate into perspective. Mining is not the main user of water resources in Mendoza, not even relative to agriculture. The real bottleneck lies in irrigation infrastructure, the low percentage of lined canals, the lack of sustained investment in water-use efficiency, and deficits in measurement and control.
The technical discussion shows that Mendoza’s water challenge is systemic, predating and independent of mining development. Addressing it requires planning, investment, and data-driven management—not simplifications or slogans.
An uncomfortable but necessary conclusion
The data presented at the Water for the Future Congress are clear: Mendoza uses most of its water without mining development, and still faces structural efficiency problems. In this context, shifting all water-related concerns onto mining is not only technically incorrect, but also diverts attention from the real issue: water infrastructure and management. For a province seeking to diversify its productive matrix, the core discussion is not who uses the water, but how it is managed and how much is lost before it reaches productive use.
