Prediction Of Groundwater Impacts For Excavations

Groundwater inflow and levels associated with excavations are important considerations for construction and operation of the completed development. Drawdown associated with excavation has potential to result in settlement, impacts on vegetation and ecosystems and the distribution of existing groundwater contamination. Inflows to excavations need to be dealt with including possible need for treatment prior to release to the surface water system.

The paper presents methods which can be used to address a range of groundwater issues associated with excavation drawing upon closed form analytical methods. The methods presented are illustrated with examples drawn from practice.

Topics discussed include:

• Prediction of maximum groundwater level over the design life of a project
• Prediction of the rate of groundwater inflow to an excavation
• Prediction of groundwater level drawdown associated with excavation.