Permanent Dewatering Systems
Dewatering and groundwater control systems are occasionally required as permanent systems, intended for very long term operation as a part of completed structures, facilities or engineering infrastructure. Permanent dewatering systems may be required to:
- Reduce leakage into below ground structures such as tunnels and basements
- Lower groundwater levels to reduce groundwater uplift loads on structures
- Control anticipated rises in groundwater levels
- Depressurise and stabilise slopes and other earth structures
- Help remediate groundwater contamination
Permanent dewatering systems can be based on either dewatering techniques or cut-off wall techniques.
Permanent systems based on dewatering can use conventional wells pumped by, for example, wellpoint or deep well systems. It may also be possible to use passive drainage systems may be used where the drainage elements such as relief wells or drainage blankets are not pumped directly but have outlets at a sufficiently low level, relative to original groundwater level, that they flow without the need for pumping.
Permanent systems based on cut-off walls and groundwater barriers can be used to reduce seepage of groundwater into below-ground structures. Commonly, artificial barriers (typically low permeability vertical cut-off walls) are used in combination with natural geological barriers such as very low permeability layers of clay or unfractured bedrock. In combination, the artificial and natural barriers act to form a complete exclusion system around the structure.
Groundwater Engineering provides complete dewatering solutions:
- Design of dewatering systems
- Well drilling and installation
- Pumping tests
- Equipment sales and rental
- Monitoring systems
- On-site operation and maintenance