Hydrochemical Characteristics and Sustainable Quality Assessment of Reservoir Water in the Junagadh District of Saurashtra Peninsula, India

Freshwater is an important natural resource for sustaining human life. The study explores the hydrochemical characteristics, water quality status and irrigation suitability of 13 surface-water reservoirs in the Junagadh District of Saurashtra Peninsula, Gujarat state, India, in pre-monsoon 2025. APHA (2017) protocols and standard values of WHO-2017 and BIS-2012/2015 were used throughout the analysis. In water quality index (WQI), 84.62% of the samples fall within the good category and 15.38% within the excellent category for domestic purposes. Sodium adsorption ratio (SAR), the sodium percentage (Na%) and residual sodium carbonate (RSC) were evaluated for irrigation suitability. In the USSL plot, most samples were in the C2S1 category, indicating low sodium hazard; few show moderate salinity. In Piper diagram, Ca2+–Mg2+–HCO3– and Ca2+–Mg2+–Cl– are dominant facies. Rock weathering is a geochemical process primarily identified by the Gibbs diagram. Based on the findings, the surface waters of Junagadh District are suitable for both domestic use and irrigation applications.