1. Introduction

MINEDW is a three-dimensional finite-element groundwater flow program specifically for mining applications. With over 30 years of development and validation at 75+ mines worldwide, MINEDW provides specialized tools to accurately predict groundwater inflows and pore-pressure distributions for safe and economical mining operations.

1.1. Mining Hydrogeology Challenges

Mining operations below the water table face two critical water-related challenges that directly impact both economics and safety:

Groundwater Inflow

When country rock is permeable, significant groundwater inflows into underground excavations and open pits, requiring extensive dewatering systems and ongoing pumping costs.

Pore Pressure Effects

In low-permeability rock, pore pressure critically affects the stability of open-pit highwalls and underground excavations, potentially causing slope failures or structural instability.

Predicting the nature and magnitude of these problems is essential for designing appropriate dewatering, depressurization, and slope management systems that ensure safe and economical mining operations.

1.2. The Need for Advanced Modeling

While numerical groundwater flow models are routinely used to predict inflows and pore-pressure distributions for mining applications, traditional finite-difference codes have significant limitations when applied to the complex geometries and detailed analyses required for mining projects. These limitations include:

Discretization Limitations

Finite-difference codes struggle with complex mining geometries. Accurate prediction of radial flow toward excavations requires fine, approximately logarithmic mesh spacing around excavation boundaries. Discrete features like faults and hydrogeologic contacts require precise representation, challenging for rectangular grid systems.

Seepage Face Estimation

The seepage face—the surface of an open-pit highwall through which lateral flow occurs—is poorly estimated by finite-difference codes. Since seepage face height directly affects both lateral inflow rates and water table positions behind highwalls, inaccurate estimates can introduce significant errors in flow predictions and pore-pressure distributions. Because pore-pressure distributions are fundamental inputs for slope stability analyses, seepage face errors produce unreliable safety factors, underestimating failure risk and compromising design decisions.

Integration with Geomechanical Analysis

For slope-stability analysis, pore-pressure data from groundwater models must be compatible with geomechanical model requirements. Traditional codes often produce data formats that require extensive post-processing, delaying the critical integration between hydrogeological and geotechnical analyses.

1.3. Development of MINEDW

To address these limitations, Itasca Consulting Group, Inc. developed MINEDW, a three-dimensional finite-element groundwater flow code specifically designed for mining applications. Built on proven algorithms originally developed by Durbin and Berenbrock (1985) [1] for the United States Geological Survey (USGS) FEMFLOW3D code, MINEDW combines robust numerical methods with mining-specific functionality.

Field Validation and Proven Performance

MINEDW development spans over 30 years of continuous refinement and field validation. Since its commercial release by Itasca in 2012, the software demonstrates extensive real-world application:

  • 75+ mines worldwide across diverse hydrogeologic and climatic conditions

  • Arid to tropical environments with complex groundwater systems

  • Decades of operational performance providing crucial validation data

  • Proven reliability confirmed through extensive field application

1.4. Acknowledgments

Itasca acknowledges the contributions from the past and current employees of Itasca and its predecessor, Hydrologic Consulting, Inc. Among them, Mr. Timothy Durbin and Dr. Lee Atkinson were instrumental in the inception and early development of MINEDW.