Abstract Afghanistan is a mountainous, arid country with limited surface water supplies. The complex geology in this country includes active tectonics and mountain ranges. Afghanistan is subdivided into three distinct hydrogeological areas: the Central Highlands, the Northern Plain, and the Great Southern Plain. Most groundwater is located in the Central Highlands, where water of sufficient quantity to meet the needs of the population is available primarily by digging wells into unconsolidated alluvial aquifers located in mountain valleys. A lack of sustainable, high-quality water supplies can have a negative impact on the ability to conduct military operations. An understanding of hydrogeological conditions is required in order to minimize exposures to natural and anthropogenic sources of contamination that may pose either acute or chronic health risks to military forces. This same scarcity of potable water can have a negative impact on the local population. Projects that improve the quantity and quality of water available to both military forces and the local population are important to improve the overall stability of Afghanistan.