<p>Groundwater is an important resource in arid and semiarid regions worldwide. Lasbela, the coastal district of Balochistan in Pakistan face water scarcity and the residents primarily depend on groundwater for drinking purpose. In such hydrologically constrained environment, water quality assessment is imperative to ensure the protection of public health and ecological integrity. The objectives were to conduct water quality analysis, assess water indices and pollution sources, develop geospatial maps and comparative analysis with other coastal zones. Laboratory and in-suite analysis of 14 water parameters (<i>n</i> = 75) were performed. Water quality index (WQI) and synthetic pollution index (SPI) were analysed. Ordinary kriging tool was used for maps, and multivariate statistical techniques were used to assess pollution sources. WQI categorized samples into 26.6%, 54.6%, and 18.6% as excellent, good and poor for drinking purposes. SPI categorised samples into 24%, 1.3%, 54.6% and 20% as suitable, slightly, moderately and highly contaminated. Both these indices showed significant strong positive correlation. The spatial patterns of analysed parameters and indices were also developed. Both geogenic and anthropogenic factors coupled with sea water intrusion contributed to contamination sources. Coastal regions of south Asia and Africa also highlighted similar findings. Thus, validating sea water intrusion attributed to overextraction of groundwater as common contributing factor for deterioration of water quality and quantity besides conventional sources. The findings provide a critical guiding tool for national and international agencies to develop targeted coastal water management and conservation plans aligned with Sustainable Development Goal targets 6.1, 6.6 and 12.2.</p> Graphical Abstract <p></p>