Flood disasters in developing countries are not solely driven by climate change but are often intensified by poorly planned infrastructure and weak water governance. This paper explores how infrastructural systems, originally designed to enable development, have exacerbated flooding in Pakistan and Nigeria’. Drawing on academic literature, government reports, and disaster assessments, the study analyzes three major events; Pakistan’s 2010 and 2022 floods and Nigeria’s 2022 flood to evaluate the paradox of progress where infrastructure becomes a source of vulnerability. In Pakistan, the canal irrigation network established in the 1840s and later expanded under the Indus Basin Development Programme disrupted natural river dynamics, contributing to over 1,700 deaths and the displacement of nearly 8 million people in 2022. In Nigeria, downstream flooding linked to water releases from Cameroon’s Lagdo Dam caused over 500 deaths, displaced approximately 790,000 people, and affected more than 1.4 million nationwide. Findings reveal that mismanaged infrastructure through levee breaching, sediment buildup, insufficient maintenance, and poor alignment with natural hydrology transforms manageable rainfall into humanitarian disasters. The paper recommends hydrologically sensitive infrastructure design, wetland and mangrove conservation, equitable land-use enforcement, and basin-wide water governance.