Sustainability Assessment Index for Surface Water Bodies for Prioritizing Management Interventions

The deterioration of freshwater resources is a major global risk, highlighting the need for a comprehensive water body sustainability framework as a decision-support tool for managing water bodies, particularly in urban areas. This study introduces the Water Body Sustainability Index (WBSI) to measure the sustainability of inland surface water bodies. The WBSI uses relevant indicators identified through both top-down and bottom-up approaches, assigns weights to these indicators and aggregates them into a composite index. It rates the sustainability of water bodies on a scale of 1–100, with 0 indicating very low and 100 indicating very high sustainability. The WBSI was applied to Najafgarh Lake in northern India in the Delhi and Gurugram regions, resulting in a score of 40.42, indicating very low sustainability. The assessment involved screening and consulting experts and stakeholders to prioritize 15 significant indicators, gathering data and organizing it into a sustainability matrix. Government policies, regulations and court orders were also examined to understand their impact on the WBSI. Recalculation of the WBSI, accounting for the positive impact of court orders and regulations on five indicators, increased the score to 52.08, placing it in the low sustainability range. Further improvements in the WBSI are expected as more data become available to quantify the positive impact on the remaining indicators post-interventions. The WBSI enables policymakers to assess sustainability, prioritize interventions and monitor the effectiveness of their actions over time, leading to the sustainable management of water bodies.