Revival of Traditional Cascade Tanks for Achieving Climate Resilience in Drylands of South India

Abstract

Traditional tanks in arid regions of India have been working to address water demands of the public for more than 2000 years. However, recent decade is witnessing growing domestic and agricultural water demand coupled with rising encroachment and ignorance toward tanks; consequently, intensifying water shortage issues. While climate change is impacting at alarming rates, local agencies have forgotten these tanks that have aided in sustainable water supply solutions for decades apart from municipal water supply. This research, for the first time, estimates water supply-demand for an arid region in South India (Madurai) and lists out the benefits if tanks were managed and desilted. Exploratory investigations for documenting seasonal domestic and agricultural unmet water demand were conducted followed by their validation through ground-truthing across the study period 2002–2019. Results indicated high unmet domestic water demand, estimating ~73% [maximum 365 thousand cubic meters (TCM)] for summer (March to May) and ~33% (maximum 149 TCM) for winter (January and February), and high unmet agricultural water demand estimating ~90% (maximum 5,424 TCM) during North-East monsoon (October to December), and ~95% (maximum 5,161 TCM) during South-West monsoon (June to September). Erratic rainfall pattern was identified as a major cause for higher fluctuations in water availability inside tanks ranging 0–50%, while lack of ownership resulted in increased siltation load ranging 30–70% of the tank's volume. The study found that the major portion of the unmet water demand can be accounted for through rehabilitation of the tanks, as under the rehabilitated tank irrigation scenario the tank storage could attain 200–400% more water than the estimated agricultural water demand. It was concluded that if the cascade tanks were managed appropriately, they could have positive impacts by reducing floods and providing water for drought seasons.

An Analytical Study for Assessing Water Productivity in Pre‐ and Post‐Rehabilitation Period of Rural Tank System

“…Uninterrupted supply of water to the fields helped in an increased number of bags/ha (i.e. from 50 to 60 bags) helping the farmers to boost their household income [61]. Furthermore, the majority of marginal farmers do not possess wells, and respondents stated that before rehabilitation, they were only able to grow for one season.…”

“…Henceforth decide on a substantial modification among mean productivity of water on seasonal crop cultivation. According to the earlier studies, in rainfed areas rehabilitating tank systems are mandatory to attain food security and minimize water constraints [69][70][71]. With respect to mean rank, annual crop like sugarcane (5.66) gives more returns in terms of money for 1 m 3 of water used followed by second season paddy cultivation (4.98) and first season paddy cultivation in the post-rehabilitation period (Table S11).…”

Sustainability of Village Tank Cascade Systems of Sri Lanka: Exploring Cascade Anatomy and Socio-Ecological Nexus for Ecological Restoration Planning

“…Surface runoff water harvesting systems through small tanks in micro-watersheds are found in several Mediterranean and Asian countries [1]. In order to achieve the targets of the Sustainable Development Goals especially SDG-2 and SDG-6, it is vital to restore these systems using community participation to enhance surface and groundwater management, especially in developing countries [2][3][4]. The Village Tank Cascade System (VTCS) is a complex socio-ecological system existing in the Dry and Intermediate Zones of Sri Lanka.…”

Developing a Web Application-Based Water Budget Calculator: Attaining Water Security in Rural-Nashik, India

“…Studies also show the increase in integrated precipitable water in India by 4.69% against a 1 °C increment in regional warming [14]. More than the scarceness of the water is the mismanagement in the usage of this limited resource at a village level [15][16][17]. The increase in the demand for water-intensive activities and the effects of climate change has underlined the urgency and significance of sustainable management of water resources to attain water security [17][18][19].…”

“…The spatial information about water sources links statistical and socio-economic information to a location, bringing much-improved understanding and policy analysis both at the local (village) and state level (Central and State) [16,17,28]. In a general, estimation of the water availability, the study of the influence of hydrological and climatological parameters on water occurrence, circulation, and distribution on the earth and earth's atmosphere, and assessment of extreme events like flood and droughts [29] and strategies to combat them are of paramount importance [22], especially while proposing the sustainable water management and security plans [14,17].…”