Modernization of traditional irrigation systems in India is becoming popular in response to the expensive development of new projects. Examination of proper management strategies, effective resource allocation, and collective action has become paramount for promoting food security and livelihoods in water-stressed catchments of Southeast Asia. Sustainable practices and conservation efforts in agriculture-dependent village ecosystems are leading themes in contemporary literature. The goal of this paper was to assess the status and restoration needs of a mosaic of rainwater harvesting irrigation tanks to meet future agricultural and household water demand in a 60 km2 rural area of Karnataka, India. We characterized 40 tanks in the region through data collected from visual observations, key informant discussions, and hydrological statistics for management in ArcGIS. This information was integrated into a Multi-Criteria Decision Analysis (MCDA) framework to prioritize and rank tanks based on attributes identified by stakeholders. Furthermore, we ranked tanks based on their potential for contributing to food security and projected their potential for water supply at various storage capacities. Water supply and potential evaluation were accomplished through the calculation of rainfall generated runoff of the river basin. These characteristics of water management were then compared with projected restoration costs under alternative siltation scenarios.
Results/Conclusions
Preliminary results show that the MCDA framework combined with the watershed delineation tools in ArcGIS serve as a valuable substitute for the current assessment and prioritization of India’s traditional irrigation system. Although extraction of groundwater resources through investments in wells has become an attractive option, the tools utilized in this study prove that better management strategies implemented in current irrigation tanks can provide sufficient water resources to large, small, and marginal farmers. The multiple use ranking system of these tanks contributes to additional income generation and maximum potential irrigation utility. The results of this study will provide district water development agencies with a scientific approach to prioritizing water restoration efforts and financial resources under limited budgetary constraints. The spatially referenced hydrologic outputs will also be beneficial for the river basin, with potential applications to other watersheds throughout South-Eastern Asia. These various conservation management tools allow for a marriage of financial, social, hydrological, and ecological factors in the restoration of existing agricultural water infrastructure in the global south.