Trockenlegen

Trockenlegen, in English often referred to as dewatering, is the practice of removing water from soil or a site to lower the groundwater level and create dry working conditions. It is commonly used in civil engineering, construction, mining, and flood management to enable excavation, foundation work, tunnel construction, or the stabilization of waterlogged areas.

The process relies on lowering groundwater through pumping and drainage systems. Typical methods include surface pumping from sumps, well-point systems (arrays of shallow, perforated wells connected to a drainage network), and deep-well dewatering using borehole pumps. Other techniques include trench drainage, gravity drainage, and, in some cases, vacuum or eductor-based systems. Projects often combine methods and are designed from hydrogeological investigations and drawdown calculations.

Planning and operational considerations are essential. A dewatering plan specifies pump capacity, discharge location and quality, and monitoring of groundwater levels. It also considers potential ground movement, impacts on nearby wells or surface water, and discharge requirements. Environmental and regulatory aspects may require permits, treatment of pumped water, and measures to mitigate sediment transport and ecological effects.

Applications are widespread: creating dry foundations for buildings and infrastructure, excavations for basements and tunnels, pipeline trenches, mining dewatering, and mitigating surface water in flood-prone areas. Trockenlegen aims to maintain safe working conditions while controlling hydrogeological impacts and ensuring compliance with local regulations.