Guidance

Temporary dewatering from excavations to surface water: RPS 261

Updated 23 April 2026

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-rps-261/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

Activity this RPS applies to

This RPS applies to short term, intermittent or temporary discharges of uncontaminated water (wholly or mainly rainwater) from an excavation to surface water.

Surface water includes:

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

This RPS does not apply to discharges to ground or groundwater.

This RPS does not apply where the activity is continued on as part of another activity which requires a permit.

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
  • minimise the level of contaminants such as silt entering the excavation
  • minimise water entering the excavation, for example from rainfall, runoff, groundwater ingress or high-water table
  • keep records for 2 years from the date of the last use of the RPS to show that you have complied with this RPS and make these records available to the Environment Agency on request

You must not:

  • pollute surface water
  • discharge at a flow rate that is more than 10% of dry weather flow (Q95 low flow) of the receiving surface water
  • discharge site drainage from surface areas such as haul roads, storage or working areas
  • 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 from a site with naturally elevated concentrations of substances which exceed environmental quality standards
  • discharge concrete wash water even if it has been treated
  • use machinery in excavations while dewatering is taking place
  • discharge water that risks the spread of non-native invasive species, parasites or disease
  • cause flooding from surface water
  • cause erosion or scouring of the banks or bed of the receiving watercourse

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 within, or less than 500 metres upstream of a protected habitat site including the following:

  • 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

Things to note

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

You can check the locations of protected habitat 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 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

Dewatering may require both an abstraction licence and a water discharge activity permit. This RPS only covers the water discharge activity.

If you are abstracting water

You must also 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:

This RPS relates to an activity that the Environment Agency considers is potentially suitable to be an exemption under the Environmental Permitting (England and Wales) Regulations 2016. A change in law would be required for this.

When you must check back

The Environment Agency will review this RPS by 30 April 2028.

The Environment Agency can withdraw or amend this regulatory position before the review date if they consider it necessary. This includes where the activity that this RPS relates to has not changed.

You will need to check back from time to time, including at and before the review date, to see if this RPS still applies.

This RPS remains in force until it is removed from GOV.UK or is otherwise identified as having been withdrawn. 

You can subscribe to email updates about this RPS. These will tell you if the RPS has changed and when it has been withdrawn. Use the ‘Get emails about this page’ feature on the RPS publication page.

If you cannot comply with this RPS

If you operate under this RPS but can no longer comply with it, you must:

Contact the Environment Agency

If you have any questions about this RPS, email enquiries@environment-agency.gov.uk with RPS 261 in the subject.

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