Water Physicochemical Parameters and Sediment Characteristics of Erah/ukhun Dam in Owan East Local Government Area of Edo State

This study investigated the physicochemical parameters and sediment characteristics of Erah/Ukhun Dam, located in Owan East Local Government Area of Edo State, Nigeria. The research aimed to assess the water quality and determine the level of heavy metal concentrations in the dam, which serves as a vital source of water for domestic, agricultural, and fishery purposes in the surrounding communities. Water and sediment samples were collected monthly from three sampling stations between January and March 2024 and analyzed using standard analytical procedures. Physicochemical parameters such as pH, turbidity, electrical conductivity, total dissolved solids, total suspended solids, dissolved oxygen, biological oxygen demand, alkalinity, hardness, chloride, sulphate, phosphate, nitrate, calcium, and magnesium were examined. Heavy metals including iron (Fe), zinc (Zn), chromium (Cr), manganese (Mn), nickel (Ni), and lead (Pb) were also determined using Atomic Absorption Spectrophotometry (AAS). Results revealed that most physicochemical parameters and metal concentrations were within the permissible limits set by the Federal Ministry of Environment (FMEnv, 2007), except for turbidity and dissolved oxygen, which slightly exceeded the standard values. Sediment samples exhibited higher concentrations of metals compared to water, following the order Fe > Zn > Cr > Mn > Ni > Pb. The findings indicate low levels of contamination and generally good water quality in the dam. However, continuous monitoring is recommended to prevent future pollution due to increasing anthropogenic pressures around the catchment area. This study provides baseline data useful for environmental management, sustainable water resource utilization, and policy formulation regarding freshwater ecosystems in Edo State and Nigeria at large.