Review: Assessment of the aquifers in South Sudan with a focus on Lakes State

The current state of knowledge on groundwater in South Sudan (a data-scarce country) is presented, based on extensive field surveys in Lakes State in the central part of the country, limited published literature, and unpublished consultancy reports. The Basement Complex and the unconsolidated sediments of the Umm Ruwaba Formation are the most extensive geological formations and are the most exploited for groundwater. The water-resource potential properties of the main Umm Ruwaba aquifer (the ‘second’ aquifer, mostly confined) in Lakes State are generally fair to good, with a shallow piezometric surface (