Urban Groundwater Depletion and Rainwater Harvesting Strategies: A Literature-Based Assessment and Proposed Framework for Bengaluru City

Abstract

Groundwater stress in Bengaluru has worsened markedly over the past decade, a trend closely tied to the city's rapid outward growth, the steady loss of green and open land, and increasingly erratic rainfall. Every major groundwater assessment unit within the city now falls under the "over-exploited" category used by national authorities, and recent estimates put the gap between water demand and available supply at several hundred million litres a day. This paper works through what the existing evidence — academic, governmental, and policy-oriented — says about the scale of this depletion and about rainwater harvesting (RWH) as a possible response. It sets out the method used to locate and weigh that evidence, then draws the findings together into a conceptual, ward-level framework built around rooftop harvesting, recharge structures, stormwater redirection, and stronger enforcement, tailored to Bengaluru's terrain and its layered municipal governance. It closes by flagging where implementation continues to fall short and what future field research would need to establish.