Groundwater flow patterns in the Obagi oil fields of south-south Nigeria

This study was an attempt to decipher groundwater flow patterns and the factors that affect it in the Obagi oil fields of south-south Nigeria. In this study, head, position and geological data were obtained from 13 hand dug wells tapping the water table and the Sombreiro and the Orashi Rivers, while water quality data was generated through groundwater sampling and analysis using standard methods. This study discovered a hidden channel system, a reversed recharge system for the Sombreiro River system with serious local groundwater quality implications. Groundwater flow in the study area has components of regional, intermediate and local flow systems, while movement is controlled by topography; recharge; a groundwater channel system running NW-SE through the middle of the study area and a system of wetlands in the Omoku and Erema areas. These wetlands which are used as sinks are also major recharge areas for the groundwater system in the study area thereby posing public health dangers. Also the dumping of industrial and domestic wastes in the wetlands may be limiting the capacity of these wetlands as sinks and purification plants for the natural hydro-geopollution cycle.