How the colonial-era water management paradigm continues to shape the Indus Delta crisis

Water management in the Indus River Basin since the colonial period has prioritised infrastructure development, neglecting the Indus Delta and its communities, resulting in severe ecological and social concequences. Today, less than 10% of natural flows reach the Indus Delta, resulting in a 92% decline in its active area since 1933. This study uses a process tracing approach grounded in historical institutionalism and political ecology to show how colonial-era irrigation systems and post-independence policies and legal frameworks entrenched centralised, technocratic governance that continues to marginalise ecological needs and local communities. We introduce the Delta Harm Score (DHS), a semi-quantitative index measuring Colonial Legacy, Power Dynamics, Equity Focus, Implementation Strength, and Delta Impact. Applied to major water and environmental policies in Pakistan, the DHS reveals consistently high harm levels in foundational instruments such as the Canal and Drainage Act (1873) and the Indus Waters Treaty (1960), Water Apportionment Accord 1991, as well as the recent National Water Policy (2018). This illustrates how elite control and infrastructural lock-ins perpetuate systemic harm to river deltas. Findings underscore persistent historical path dependencies in contemporary refoms. The study calls for legally mandated environmental flow thresholds, participatory basin governance with Delta representation, and institutional redesign to integrate climate change. The DHS offers a replicable framework for comparative and sustainable delta governance.