Dewatering, as its name suggests, is the process of removing surface and subsurface water from a construction site.
Whether you have to remove small amounts of water in case of shallow excavations (up to 1.5 m deep) or have to control large quantities of water in deep excavations (over 3 m deep), you will need to consider a wide range of methods to make sure adequate precautions have been taken.
1. Why Dewatering?
Dewatering provides dry and stable conditions for excavations, allows to increase the stability of the soil, and ensures workers’ safety.
If for some reason surface and sub-surface waters are not properly collected and disposed of, they can pose significant hazards during construction site preparation and, later on, during the building’s life cycle
2. Dewatering By A Well Point System.
This method features easy installation, and it’s relatively cheap and flexible, being practical and effective under most soil and hydrologic conditions. Wells are drilled around the construction area and pumps are placed into these wells.
Wellpoint systems consist of a series of small-diameter wells, connected by a header pipe to a centrally located suction pump. Groundwater is abstracted via the wellpoints from a vacuum generated by the pump. Groundwater can be lowered about six metres by this method..
