In the heart of Tamil Nadu, India, an intricate dance between people, water, and the environment is unfolding, one that could reshape the future of sustainable water management and agriculture. A recent study, led by Raj Rengalakshmi from the M S Swaminathan Research Foundation in Chennai, delves into the socio-hydrological dynamics of tank cascade systems, offering insights that could echo far beyond the fields of South India.
Tank cascades, interconnected systems of tanks or ponds, have long been the lifeblood of rural livelihoods, providing irrigation and ecosystem services. However, these systems are facing unprecedented challenges, with climate risks and shifting agrarian relations threatening their very existence. Rengalakshmi’s study, published in the journal ‘Frontiers in Water’ (translated to ‘Frontiers in Water’), sheds light on these complexities, highlighting the urgent need for sustainable management strategies.
The study, which spanned a decade from 2004 to 2024, paints a stark picture of change. Farmers’ dependence on these tanks for irrigation has plummeted, with some areas seeing a drop of up to 54%. Land use has shifted dramatically, with a significant reduction in cropping areas and an increase in fallow land and built-up areas. “The surface runoff has increased, while the groundwater level shows a decreasing trend,” Rengalakshmi notes, pointing to a shift from community-based surface water irrigation to individual groundwater extraction.
This shift has profound implications, not just for agriculture, but also for the energy sector. As groundwater levels drop, the energy required to pump water increases, leading to higher costs and greater strain on energy resources. Moreover, the degradation of tank infrastructures and the decline of community-based water governance systems signal a loss of social capital and interconnectedness among farmers.
Rengalakshmi’s research underscores the importance of understanding these socio-hydrological principles in designing sustainable tank management initiatives. “The hydrological status of the tank cascades is closely interconnected with good governance and strategies for the sustainability of institutions in social and financial dimensions,” she explains. This requires both the right policy and a translational framework to put tank cascades at the center of development plans.
The study’s findings could shape future developments in the field, offering a roadmap for restoring and managing tank cascade systems. By integrating socio-hydrological principles into policy and practice, stakeholders can work towards sustainable water management, ensuring the resilience of these systems in the face of climate change and shifting agrarian relations.
As we grapple with the challenges of a changing climate and growing energy demands, Rengalakshmi’s research serves as a timely reminder of the intricate connections between water, energy, and society. It’s a call to action, urging us to rethink our approaches to water management and embrace sustainable, community-centered solutions. After all, the future of our fields, our farms, and our energy systems may well depend on it.