Ensuring water for energy and food production in the Andes-Amazon headwaters

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A new study, focused on a remote region of the Peruvian Andes where the waters of the Amazon originate, carries lessons for hydropower operators and farming communities worldwide: collaborating on sustainable land management is the best decision they can make for the long-term viability of their businesses and livelihoods. It also opens opportunities for restoration of degraded ecosystems.

Research from the Stanford-based Natural Capital Project (NatCap) in Communications Earth & Environment integrates hydropower operations with watershed processes and climate projections in a novel, high-resolution modeling approach for the Huallaga River Basin, upstream of the Chaglla Dam.

It provides a detailed picture of how climate change will increase water shortages, and points to investments in upstream reforestation and sustainable irrigation as the most effective paths toward meeting these challenges.

"This study is exciting because this is the first time climate change, hydropower, and land management practices have been put together in a robust decision-making approach," said Zhaowei Ding, a postdoctoral researcher at NatCap and lead author on the paper.

"In this region, people had looked at the relationship between hydropower and deforestation, or hydropower and food, but they were not connected. Now, we can show where water goes in the basin and we can optimize our management suggestions."

Climate-induced water shortages turn up the pressure

Despite serious social and environmental impacts, hydropower remains an important source of low-carbon energy in many parts of the world, including Latin America and Asia. However, hydropower dams cannot operate below a certain threshold of water flow. Reduced rainfall resulting from climate change will exacerbate the problem.

So too will less rain during the growing season. Farmers upstream of hydropower plants will increasingly turn to irrigation to ensure their livelihoods, reducing the water available downstream. These changes will likely exacerbate conflict between the energy and agricultural sectors.

Waldo Lavado, a co-author and researcher at the National Service of Meteorology and Hydrology of Peru, noted that water resources in the Peruvian Andean-Amazonian basin are quite vulnerable to changes in land use and to climate change.

"For the first time, this research scientifically documents possible projections of these changes—the first step to understanding the water-energy-food-ecosystem nexus in Peruvian basins with increasingly marked human influences."

The researchers analyzed thousands of possible land and water use scenarios and found no win-win solutions for resolving tensions between water, energy, food, and ecosystems. Unplanned expansion of irrigation in this region could strongly impede the hydropower plant's ability to function in the dry season, when hydropower is most valuable for the Peruvian power grid.

At the same time, thousands of small-scale producers have long relied on rain-fed agriculture for their food security and livelihoods, and for contributing to the national market. In this context, irrigation helps farmers mitigate increasing uncertainty.

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Nature offers damage control

Nonetheless, the study found that impacts to both the energy and food sectors could be lessened using nature-based approaches. Investments in upstream reforestation and the creation of protected areas, by compensating farmers to plant trees instead of crops, would increase water availability for downstream hydropower by reducing irrigation needs.

Forests also help retain soil, so this would lessen erosion and sedimentation, which impede dam operations. The modeling helped identify low-yield areas where farms use a lot of water for irrigation but aren't producing similarly large crops—potentially prime locations for making this switch. This approach could be combined with investments in irrigation efficiency, like drip irrigation systems, in remaining crop production areas to maintain or increase local food production.

"This type of information can contribute to local stakeholders' decision-making processes around development," said Andrea Baudoin Farah, assistant professor at Colorado State University, former postdoctoral researcher with NatCap, and a co-author of the paper.

"Local farmers and communities are well aware of the need to preserve the ecosystems and landscapes that sustain their production systems, but they face significant challenges in a changing environment."

Baudoin Farah noted that Andean peasant communities have deep knowledge of the interconnections between ecosystems and food production, despite being historically relegated to the steepest, most marginal lands, and neglected in terms of supportive infrastructure.

"Climate change is exacerbating their already-vulnerable livelihoods. Studies like this one point to the need to channel funds to support farmers in their efforts to conserve soils and implement sustainable production systems."

Scaling the approach in other regions

"This study shows that natural capital approaches, in this case like investing in ecosystems to secure water supplies and reduce sedimentation, are the main lever at this nexus of food, energy, climate, and water," said Tong Wu, a senior scientist & associate director of the NatCap China Program, which collaborated on this research.

"They are like the router through which all the different cables go through. It's not just one solution—it's the best solution."

The researchers hope the study's findings can motivate dialogue between hydropower operators and upstream stakeholders across Latin America. The largest dams in the world are located in Asia, so they are also engaged in ongoing conversations with key actors in the hydropower sector there about scaling up this nature-based approach to addressing the water crisis that is headed their way.

With climate change, the value of water will be higher and competition for it will be stronger. "If hydropower operators want to maintain their revenue, they will need to increase their investments in nature upstream of their dams," said study senior author Rafael Schmitt, a lead scientist at NatCap and project lead.

"Our team's modeling framework is an important step forward in defining eco-compensation mechanisms—like paying farmers not to farm, or where to implement protected areas—in a way that is science-based and robust, despite the great uncertainties introduced by future climate change," Schmitt added.

More information: Zhaowei Ding et al, Sustainable land and irrigation management to limit loss of hydropower in the Andes-Amazon headwaters, Communications Earth & Environment (2024). DOI: 10.1038/s43247-024-01738-4

Journal information: Communications Earth & Environment

Provided by Stanford University