Dewatering: How It's Done

October 22nd, 2019
dewatering.jpg

If you have read any of our past blog posts on dewatering, you know why it is such an important process for construction and building maintenance. Of course, water is essential to all landscapes with greenery -- in general, lawns need about an inch of water per week to stay happy and healthy. There can be too much of a good thing, though; excess water in the ground can wreak havoc on a structure, infiltrating and weakening the foundation.

Construction sites can easily come across issues with excess groundwater as well. Due to the prevalence of excavation pits and surfaces of varying levels on these sites, water has a tendency to accumulate in these low areas. Small amounts of water can quickly become a nuisance, while a bit more can halt work entirely. This is where dewatering becomes essential, but how exactly is this crucial process accomplished?

Horizontal drainage

This simple, elegant method is a common solution for temporarily lowering an area's water table. First, a drainage pipe is installed in a trench, wrapped in a perforated pipe -- this is generally done around six meters underground. This pipe is connected to a pump, which will keep the water table lower for as long as it is active. These changes are not permanent; once the pump has been shut off, the water table will return to its normal level.

Boring a deep well

If an area's soil is sufficiently permeable, deep well boring can thoroughly dewater a site. Once a spot has been selected for a deep well, a hole is bored and filled with a slotted liner. Next, a submersible electric pump is installed in the well to remove water.

This outflow of water creates a hydraulic gradient, causing water from the surrounding soil to flow into the well and restore an even distribution. Once the pumping is complete, there will be a dry cone of depression surrounding the well. If a larger site needs to be dewatered, this dewatering system can be installed in a ring around the wet area.

For any dewatering services you need, contact Hydrograss Technologies, a trusted name in dewatering and engineered hydraulic solutions.