Surface water pollution is now a major environmental concern on a worldwide scale. To maintain the water quality and to understand the current state of the water resource in Brahmani River, Odisha, surface water monitoring and assessment are crucial. In this study, we utilized three models—Weighted Arithmetic (WA)-Water Quality Index (WQI), Synthetic Pollution Index (SPI) and multi-criteria decision-making (MCDM) approach namely Compromise Programming (CP)—to predict surface water drinking suitability. A total of 15 water samples were collected from 7 monitoring sites and were analyzed using standard methods. All assessing parameters were discovered to be within permissible bounds for agricultural, drinking, and environmental uses. The physicochemical trends indicated a sequence of cations: Ca2+ > Mg2+ > Na+ > K+, and the anions are reflected as: SO42− > Cl− > NO3− > F− > PO43−. Subsequently, several indices, such as WA-WQI and SPI were calculated and indicated that water in the river at Q-(1), (3), (7), and (2) had high levels of Ca2+, SO42−, TDS, EC, and Mg2+ concentrations, altered pH, and elevated DO values. The WA values revealed that 57.14% sites were the most polluted which rendered them unsuitable for drinking or bathing. Notably, the majority of the sites used for sampling have SPI values > 0.7, indicating high levels of pollution. The mid-stream stations such as: Q-(4), (5), and (6), were categorized under good water zone. The results obtained by CP, demonstrated a value of 0.941 at Q-(1), 0.813 at Q-(2), and 0.649 at Q-(7). These highly polluted areas demonstrated that fertilizer, organic waste, and soil leaching were the main causes of variations in water quality. This knowledge can be helpful to planners, policy makers, and managers of water resources in creating plans that will ensure the river's cultural and aesthetic value is preserved for future generations.