Passive dewatering

Dewatering refers to the removal of groundwater and/or surface water from a site before construction work commences. Passive dewatering occurs when groundwater is discharged to the surface under the influence of gravity. It is classed as a form of water abstraction (the act of taking water from a source of supply).

Most passive dewatering schemes are small and do not pose a risk to the environment or water table. In these instances, it may not be necessary to obtain a water abstraction licence from the Environment Agency.

Additional guidance on passive dewatering is available from the Environment Agency, [[w/index.php?title=W/index.php%3Ftitle%3DW/index.php%3Ftitle%3DRef_https://www.gov.uk/government/publications/passive-dewatering-regulatory-position-statement/passive-dewatering-regulatory-position-statement%26action%3Dedit%26redlink%3D1%26action%3Dedit%26redlink%3D1&action=edit&redlink=1|Passive dewatering: regulatory position statement]] (RPS). This guidance states that an RPS only applies to abstractions that were exempt under section 29(1) of the Water Resources Act 1991 (before section 5 of the Water Act 2003 was published). This includes passive dewatering, for example to:

• Prevent flooding to roads and railway cuttings.
• Prevent interference with mining, quarrying, engineering or building operations.
• Provide back wall drainage at landfill sites.

Ref [[w/index.php?title=W/index.php%3Ftitle%3DW/index.php%3Ftitle%3DRef_https://www.gov.uk/government/publications/passive-dewatering-regulatory-position-statement/passive-dewatering-regulatory-position-statement%26action%3Dedit%26redlink%3D1%26action%3Dedit%26redlink%3D1&action=edit&redlink=1|https://www.gov.uk/government/publications/passive-dewatering-regulatory-position-statement/passive-dewatering-regulatory-position-statement]]

[edit] Related articles on Designing Buildings

• Dewatering construction sites.
• Environment Agency.
• Groundwater.
• Raising awareness of dewatering regulation.
• Water abstraction licence.
• Water engineering.
• Water impoundment licence.
• Water management.

[edit] External resources

• Environment Agency, Passive dewatering: regulatory position statement.