Abstract
<jats:p>Boeng Sneh Lake (BSL), a 3,924-hectare freshwater wetland in Cambodia’s Mekong Delta, is a critical water resource that supports agriculture, domestic water supply, fisheries, biodiversity conservation, and flood regulation. This study assessed the lake’s hydrological dynamics and their implications for Integrated Water Resources Management (IWRM) under growing pressures from climate variability and increasing water demand. Using an integrated socio-hydrological approach, this study combined a decade of meteorological data (2014–2024), remote sensing analysis, a bathymetric survey comprising 121 systematic depth measurements supplemented by 19 targeted measurements within the nine deep pools, stakeholder consultations, and field investigations conducted in 2025. The findings revealed pronounced seasonal fluctuations in lake storage, with wet-season volumes reaching 80–100 million m³ but declining to critical levels of 5–15 million m³ during recent dry seasons, well below the operational threshold of 27 million m³ required to sustain the domestic water supply and ecological refugia. Expanding irrigation for triple-cropped rice and increasing domestic water abstraction have intensified competition among water users, threatening fisheries and ecosystem health in the region. This study highlights the value of a Google Earth Engine-based monitoring platform and the District Technical Working Group (DTWG) as innovative tools for evidence-based collaborative water governance. It recommends a trigger-based water allocation framework, demand management measures, enhanced hydrological monitoring, and stronger institutional coordination to improve the resilience and sustainability of BSL under future climatic and socioeconomic pressures.</jats:p>