Guidance

Temporary dewatering from excavations to surface water: RPS 261

Updated 6 January 2023

Applies to England

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This publication is available at https://www.gov.uk/government/publications/temporary-dewatering-from-excavations-to-surface-water/temporary-dewatering-from-excavations-to-surface-water

This regulatory position statement (RPS) does not change your legal requirement to get a water discharge activity permit when you have a short term, temporary discharge of uncontaminated water (wholly or mainly rainwater), from an excavation to surface water.

However, the Environment Agency will not normally take enforcement action against you if do not comply with these legal requirements provided:

  • your activity meets the description set out in this RPS
  • you comply with all the conditions set out in this RPS
  • your activity does not cause (and is not likely to cause) pollution of the environment or harm to human health

When this RPS applies

This RPS applies to short term, temporary discharge of uncontaminated water (wholly or mainly rainwater) from an excavation to surface water. This RPS does not apply to discharges to ground or groundwater.

Surface water includes:

  • rivers
  • streams
  • estuaries
  • lakes
  • canals
  • coastal waters

Liquid or wastewater includes:

  • poisonous, noxious or polluting matter
  • waste matter
  • trade effluent
  • sewage effluent
  • contaminated surface water

Uncontaminated, clean water is water that is wholly or mainly clear rainwater or infiltrated groundwater that has collected in the bottom of temporary excavations on an uncontaminated site.

Conditions you must comply with

You must:

  • discharge only uncontaminated, clean water
  • discharge only to surface water
  • discharge for no more than 3 consecutive months
  • plan how to minimise the level of contaminants such as silt entering the excavation
  • plan how to dispose of water that enters the excavation
  • plan not to use machinery in excavations while dewatering is taking place
  • minimise water entering the excavation, for example from rainfall, runoff, groundwater ingress or high water table
  • consider using sustainable urban drainage construction methods
  • have a method statement that minimises the risk of pollution
  • contact the Environment Agency if your discharge rate is more than 10% of the dry weather flow (Q95 low flow) rate of the surface water and dilution is low – a high discharge rate may increase flood risk or have other local environmental consequences
  • keep records for 2 years that show you have complied with this RPS and make these records available to the Environment Agency on request

You must not discharge within, or less than 500 metres upstream of, a:

  • site of special scientific interest (SSSI)
  • special area of conservation (SAC)
  • special protection area (SPA)
  • site of community importance
  • Ramsar site
  • site in the process of becoming a SAC, SPA or Ramsar site (‘potential SPA’, ‘possible SAC’, ‘candidate SAC’, ‘site of community importance’ or a ‘proposed Ramsar site’)
  • marine conservation zone
  • conservation site, such as an ancient woodland, or a local and national nature reserve
  • local wildlife site

You can check the locations of these sites using Magic map. Find out how to use Magic map. Check the locations of local wildlife sites through your local council. Or you can ask the Environment Agency to check for protected sites by using their pre-application advice service. Heritage and nature conservation screening will identify other protected features not currently found within Magic map, such as local wildlife sites and local nature reserves.

You must not discharge for more than 3 consecutive months. The water discharge activity may stop during this time, but the clock continues and is not reset. If the water discharge activity is likely to go over 3 consecutive months then you need to  apply for a water discharge activity permit.

You must not:

  • discharge silty water containing fine or coarse suspended solids into surface water
  • discharge site drainage from surface areas such as haul roads, storage or working areas
  • pollute surface water
  • discharge water containing any chemical dosing agents, flocculants or coagulants
  • discharge from a site which is contaminated by oil, metals, hydrocarbons, solvents or pesticides or other polluting substances
  • discharge water that results in the spread of non-native invasive species, parasites or disease
  • cause flooding from surface water
  • cause erosion of the banks or bed of the receiving watercourse
  • discharge concrete wash water even if it has been treated
  • discharge from a site with naturally elevated concentrations of substances which exceed environmental quality standards

This RPS does not apply to any other activity, even if it is under the same legislation. You may still need other permits or licences for other activities you carry out.

You must apply for a water discharge activity permit if:

  • your water discharge is from ‘pump and treat’ (pumping out contaminated groundwater or water from contaminated land so it can be treated)
  • your water discharge is from quarry activities
  • you cannot comply with the conditions in this RPS

You also must apply for a water abstraction or impoundment licence if you abstract more than 20 cubic metres of water a day.

You do not need to apply for a water abstraction or impoundment licence if you abstract from:

When you must check back

The Environment Agency will review this RPS by 30 April 2024. You will need to check back then to see if it still applies or if you need to apply for a water discharge activity permit.

The Environment Agency can withdraw or amend this enforcement position before it expires if they consider it necessary. This includes where the temporary dewatering from excavations to surface water that this RPS relates to has not changed.

If you cannot comply with this RPS

If you operate under this RPS but think you may no longer be able to comply with its conditions, you must tell the Environment Agency immediately.

Contact the Environment Agency

General enquiries

National Customer Contact Centre
PO Box 544
Rotherham
S60 1BY

Email enquiries@environment-agency.gov.uk

Telephone 03708 506 506

Telephone from outside the UK (Monday to Friday, 8am to 6pm GMT) +44 (0) 114 282 5312

Monday to Friday, 8am to 6pm.

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