High water table levels and artesian pressures are major issues when building excavations underground.

High water tables produce unstable ground conditions during construction which can result in high flows entering an excavation.

High artesian pressures below an excavation can result in the sudden heave of  an apparently dry excavation caused by excess pressures in a confined layer just below the formation level.

OGI’s combined approach of designing dewatering and pressure relief systems, together with managing the system installation, ensures that the construction site is dewatered to a safe and stable level to allow continuous excavation. OGI’s systems also allow for the groundwater to be abstracted with a sufficiently low silt content for the disposal of water directly to a water course.

Since 1989, OGI has focused its knowledge and practical experience on the challenges presented to the construction industry by groundwater.  The company continues to develop services to meet the needs of clients when constructing in challenging ground conditions.  Our current services range from consultancy advice and groundwater modelling to a specialist sub-contracting service, which can involve either temporarily or permanently lowering the water table.

We recommend a planned approach to groundwater management which can result in cost savings for the project from construction progress, transportation and disposal, health & safety, environmental issues or the potential abandonment of the project or structure. For more detailed information on past projects please click here.