This study examines the dynamics of riverside settlements in Central Kalimantan, with a particular focus on Palangka Raya City, to understand how traditional ecological knowledge and cultural practices intersect with contemporary urbanization and environmental pressures. Situated within the broader discourse on sustainable urban development, the research examines how the Dayak Ngaju people's enduring relationship with riverine environments. It offers valuable insights into balancing cultural continuity and ecological integrity in rapidly transforming urban landscapes. As Palangka Raya emerges as a strategic urban node, it faces mounting pressures from infrastructure expansion, land-use change, and socio-economic modernization— threatening the sustainability of indigenous lifeways and ecosystems. The study employs a mixed-methods approach, combining literature reviews, drone-based spatial observation, structured surveys, and participatory engagement with local communities. This methodological integration provides a nuanced and multi-scalar understanding of environmental and socio-cultural transformations in river-edge settlements. The findings reveal that traditional practices—such as seasonal fishing, floating cultivation, and ritual-based spatial organization— play a crucial role in maintaining ecological balance and social cohesion. These practices, however, are increasingly marginalized by top-down planning and fragmented urban governance. The study concludes that sustainable development in Palangka Raya requires a multi-dimensional framework that integrates indigenous knowledge systems, participatory planning, and adaptive environmental governance. It contributes to the fields of urban anthropology, environmental planning, and cultural sustainability by proposing a hybridized model of development that is rooted in both local wisdom and scientific innovation. Practical implications include informing culturally sensitive urban policies, while social implications point to the empowerment of Indigenous communities in shaping future cityscapes. While the study offers meaningful insights, its geographically narrow scope and absence of longitudinal data limit the generalizability of its findings; nonetheless, it provides an initial step toward more comprehensive, comparative research on riverine urban transformations across Southeast Asia. © 2025 by authors, all rights reserved.