3 Key Hydrogeological Concepts Applied in Mining Operations

This section provides an overview of key hydrogeological concepts that arise in mineral resource development projects. Application of these concepts in site investigations, dewatering and depressurization of mine workings, seepage assessment and management, and mine closure follow in subsequent sections. Also included is a discussion of representative hydraulic properties of the various types of mine waste materials. Throughout these discussions, it is important to keep in mind the accuracy with which hydrogeological data and calculations should be represented. Mining environments often have complex geology and uncertain spatial and temporal variations in conditions such as recharge rates. There are practical limits on the number of boreholes that can be used to define subsurface conditions at each stage of a site investigation. Field-scale hydraulic conductivity estimates never have accuracy to the second decimal place; some argue using even a single decimal place is not appropriate. This reality should be reflected in the number of digits used when reporting calculations of water flows and solutes fluxes.