Hydrochemical and Irrigation Characteristics of Surface Water from Creeks around Okrika Communities, Rivers State,Nigeria

This study evaluated the hydrochemical characteristics, drinking water suitability and irrigation potential of surface water from selected creeks in Okrika communities, Rivers State, Nigeria. Surface water samples were collected from designated stations across Okochiri, Ekerekana, Okpoka-Toru, and Oba Ama Creeks during both wet and dry seasons to capture spatial and temporal variability. Standard analytical procedures were employed to determine physicochemical parameters, and hydrochemical indices including Water Quality Index (WQI), Sodium Adsorption Ratio (SAR), Soluble Sodium Percentage (SSP), Magnesium Hazard (MH), Residual Sodium Carbonate (RSC), Kelly’s Index (KI), and Permeability Index (PI) were computed to assess suitability for drinking and irrigation. Hydrochemical facies and irrigation classifications were further evaluated using Piper, Wilcox, and United States Salinity Laboratory (USSL) diagrams.WQI values ranged from 178.43 to 235.72 across stations, categorizing all sampled waters as unsuitable for drinking according to WHO and Nigerian standards. The elevated WQI values were primarily driven by very high electrical conductivity (17,130– 20,086 µS/cm) and chloride concentrations (up to 7,846.02 mg/L), indicating strong saline influence and possible anthropogenic inputs. Hydrochemical facies identified from the Piper diagram revealed a dominant Ca–Mg–Cl–SO₄ water type, characteristic of hard, saline waters influenced by seawater intrusion and industrial discharges. Irrigation indices showed mixed suitability. SAR values (0.554–1.446) placed all samples in the “excellent” sodium hazard category; however, SSP and KI indicated moderate sodium risk at one station (SSP = 54.11%; KI = 1.058). Wilcox and USSL diagrams classified the waters predominantly as C4–S1 (very high salinity, low sodium hazard), implying that salinity, rather than sodicity, is the principal constraint to irrigation use. Overall, the creek waters of Okrika exhibit significant salinity-driven degradation linked to estuarine mixing, tidal influence, and anthropogenic pressures. While sodium hazard remains relatively low, elevated ionic strength severely limits domestic and agricultural applications without substantial treatment or management interventions. Continuous monitoring and integrated pollution control strategies are therefore recommended to mitigate long-term ecological and agricultural impacts in this coastal environment.