The Enduring Value of Traditional Tank Irrigation Systems
Ancient water harvesting systems, such as those from the Indus Valley Civilization (~3500 BCE), have been vital for irrigation and climate resilience, especially in arid regions. One such prominent system in South Asia, called tank irrigation, initially thrived through community management but declined post-independence due to colonial policies and neglect in Sri Lanka and India. This study evaluates current policy frameworks and rehabilitation programs to enhance the resilience of these systems in India, develop strategies for their protection and adaptation to climate change, and integrate global lessons for sustainable development.
Evaluating the Current Status of Tank Irrigation Systems
The analysis showed that pilot projects for tank rehabilitation had limited success in achieving sustainability under current climate conditions. Tank irrigation systems are crucial for adapting to extreme weather, including floods, droughts, and heat waves, replenishing groundwater, reducing soil erosion, and ensuring reliable water supplies. Traditional water harvesting technologies support 17 Sustainable Development Goals (SDGs), including clean water access, hunger reduction, gender equality, and climate action. Integrating AI and machine learning in water management benefits disaster response, while eco-tourism aids system maintenance and cultural awareness.
Navigating Policy Reforms and Institutional Arrangements
The study underscores the need for policy reforms to enhance tank rehabilitation and institutional arrangements. It calls for increased beneficiary participation and constitutional recognition of current practices. Strategic, national-scale assessments and resilience targets are recommended to improve the effectiveness of such water harvesting systems in mitigating natural hazards and enhancing environmental services.
The Challenges of Declining Tank Irrigation Systems
During the next few decades, India will suffer seasonally and regionally with severe water shortages. Agricultural water consumption, the most significant contributor to the demand for water, has been increasing for the past few decades in response to the growing and more affluent population. It is well known that, in India, water harvesting structures such as tanks, ponds, lakes, etc., have traditionally been used to collect water, particularly in rural settings where agriculture remains the principal occupation.
The Historical Significance of Tank Irrigation Systems
Traditionally, these structures were designed to facilitate rainwater storage during the monsoon season, which is applied in various ways during the non-monsoon season. The ancient tank structures in South Asia, including those in Dholavira from the Indus Valley Civilization dating back to around 3,500 BCE, underscore the region’s enduring water management and tank irrigation tradition. These early systems were marked by sophisticated designs featuring large reservoirs, step wells, and channels, setting a precedent for sustainable water management through community involvement.
This tradition continued and evolved throughout history, notably with the cascading tanks, designed and constructed over 2,000 years ago by rulers, philanthropists, and local communities due to their extraordinary engineering and managerial skills. Numerous tanks and reservoirs were built in India and Sri Lanka during the medieval period, illustrating the crucial role of community-managed water resources.
The Decline of Tank Irrigation Systems
Despite the historical significance of tank irrigation systems, they have degenerated due to unwarranted political interventions and changing socio-economic dynamics, particularly during the colonial period. As a result, the ownership of common pool resources, such as tank systems, deteriorated, and village-level institutions disappeared. This management transfer from local communities to colonial governments further exacerbated the decline of traditional water management practices.
The unprecedented degradation of tank systems and the further expansion of groundwater-based well irrigation continued even after India’s independence in 1947. Nonetheless, the degradation slowed down post-colonization until the 1980s. Meanwhile, the green revolution in India (which started during the 1960s) significantly experienced an unprecedented rise in pump-based well irrigation systems, enabled by the commencement of the energization of the groundwater extracting mechanisms in the early 1980s. This led to a further shift from community-based water sources (like tanks) to individual-based water sources.
The Need for Systemic Reform
The collective distress of the changed water policy amidst institutional neglect is a modern challenge to continuing tank-based irrigation practices, especially in the semi-arid or dry region of India. Water management and distribution are now centralized under the current situation, and people’s reliance on the government has hampered community engagement in water management, causing the traditional water harvesting method to fail.
As the water situation worsens, there is an urgent need for systemic reform in water management and the revival of traditional systems. The sustenance of such water harvesting technologies is paramount even in the 21st century, given rising water insecurity due to environmental and climate change implications and anthropogenic stressors.
Strategies for Reviving Tank Irrigation Systems
Over the past four decades, tank rehabilitation programs have been driven by several pressing reasons, including the benefits of tanks for groundwater recharge, as well as considerations of equity, stability, and security. The knowledge of this hydrogeological behavior (groundwater storage potential) provided scope for replenishing wells in the tank command and tank bed areas, facilitating irrigation for both tank-command farmers as well as tank-bed farmers.
Addressing Stakeholder Conflicts and Community Engagement
However, the rising struggle among the stakeholders is becoming prevalent due to changing socio-economic and market contexts. Field experience has shown that not considering the community’s perception while designing rehabilitation and revival programs may lead to a conflict of interest. For instance, in Tamil Nadu, degraded tanks provided several services to the village communities, such as livestock management and obtaining silt from the tank bed for their farm. Reviving tanks may adversely affect communities currently benefitting from them.
Designing policies for modernization and rehabilitation programs must follow Participatory Rural Appraisal (PRA) in the village context to contemplate local perspectives. The Water User’s Association (WUAs) must be part of the project in urban and rural contexts to collect wide-ranging inputs before the program implementation. WUAs are community-based organizations that manage and maintain water resources, including tank systems, but they face challenges such as limited resources and technical expertise.
Evolution of Tank Rehabilitation Policies
Tank rehabilitation started around four decades ago, with the primary objective of increasing productivity in agriculture. Over time, the focus shifted to alleviating poverty, generating employment opportunities, and considering the tank cascade system as a whole rather than an individual tank. Attention to the landless and poor, apart from farming and fishing communities, was given by developing Tank User’s Groups (TUGs) and involving them in income-generation activities.
Given water scarcity and security issues, the programs launched post-2000 focused more on cascades of tanks (system tanks) for catchment development, de-siltation, bund strengthening, and improvement of supply channel and control structures. This shift occurred due to experiencing more advantages while augmenting structural treatments under semi-arid or dry conditions in cascading tanks against the individual tank (non-system tank).
Challenges and the Way Forward
Despite several advances in rehabilitation programs, threats and challenges continued to exist. A significant criticism is the absence of post-rehabilitation backing, such as for minor structural repairs or modifications, provisions of getting additional funds, and further assistance in training and capacity building. Effective involvement of stakeholders for whom the tank is still the primary income source, especially in decision-making, implementation, operation, and maintenance of the rehabilitated tanks, remains a key concern.
To address these challenges, policy changes considering local and regional variabilities with a primary focus on addressing collapsed livelihood opportunities for local communities (such as landless farmers), food insecurity, environmental water mismanagement, and regional and ecological imbalances in the vicinity of tanks are necessary. Strategies for real-time tank policies need to be introduced in a rational way of drafting policies.
Integrating Traditional Water Harvesting with Modern Practices
Tank Cascade Systems (TCS), or any analogous traditional water harvesting technique, represent a time-honored approach to water collection employed across diverse regions for centuries. These systems provide numerous benefits, aligning closely with the objectives of the Sustainable Development Goals (SDGs).
Harnessing the Benefits of Traditional Water Harvesting
Traditional water harvesting technologies have created employment possibilities at the local level, augmenting incomes and alleviating poverty. They facilitate water provision for irrigation, enhancing agricultural productivity and mitigating hunger. By capturing and storing water, these systems allow irrigation during dry periods, contributing to food security.
Implementing traditional water harvesting technologies has increased opportunities for education and income generation among women and girls, who typically bear the responsibility of water collection. These systems also facilitate the storage of rainfall, enhancing water availability for various purposes and promoting accessible and safe water resources.
Adapting to Climate Change and Promoting Sustainability
TCS and traditional water harvesting systems can help bring climate change resilience by mitigating floods, enhancing drought resilience, and adapting to heatwaves. They can also reduce dependence on external water sources and enhance ecosystem services, such as soil conservation and groundwater recharge.
Leveraging Emerging Technologies
Given the limited applications of Artificial Intelligence (AI) and Machine Learning (ML) in enhancing TCS, there exists a substantial opportunity to re-evaluate traditional water harvesting approaches through the lens of advanced AI-ML technologies. AI-ML techniques can enhance TCS efficiency, particularly in forecasting extreme weather events, optimizing irrigation schedules, and developing water distribution plans to ensure equitable access during scarcity.
The integration of AI, Deep Learning, and ML with Internet-of-Things (IoT) technologies holds significant potential for improving water supply and service delivery efficiency, addressing complexities in water management systems. This synergistic approach can empower communities to manage and mitigate the impact of natural disasters proactively, fostering long-term resilience.
Conclusion
The restoration and rehabilitation of traditional water harvesting systems, such as the Tank Cascade System (TCS), offer significant visions for global water management, environmental sustainability, and climate resilience. By integrating ancient knowledge with modern technology, engaging local communities, and implementing supportive policies, these systems can provide reliable water sources, enhance groundwater recharge, reduce soil erosion, and improve water quality.
Addressing the challenges faced by tank irrigation systems, such as stakeholder conflicts and the lack of post-rehabilitation support, requires a holistic approach that considers local and regional variabilities. Strategies for real-time tank policies, increased community participation, and the integration of emerging technologies can pave the way for the sustainable management of these time-honored water harvesting practices.
As the global community strives to achieve the Sustainable Development Goals, the revival and protection of traditional water harvesting systems like TCS can play a pivotal role in enhancing water security, agricultural productivity, climate adaptation, and environmental conservation. The lessons learned from the Indian experience can be valuable for regions around the world facing similar water management challenges.
