Guidance

Low risk impounding activities: RPS 302

Published 3 October 2024

This guidance was withdrawn on 8 November 2024

This regulatory position statement has been withdrawn because it can no longer be used.

The guidance on how to check if you need a licence to impound water defines ‘low risk impounding activities’ and gives a checklist you can assess against.

Applies to England

This regulatory position statement (RPS) does not change your legal requirement to have and comply with an impounding licence when you either:

• construct or change any impounding works on any watercourse
• cause the flow of any watercourse, including some lakes, reservoirs and ponds, to be obstructed by impounding works

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

• your activity meets the description set out in this RPS
• you comply with the conditions set out in this RPS

Types of impounding activity this RPS applies to

This RPS applies to the following low risk impounding activities:

• maintenance works
• flood prevention measures
• temporary works
• works to an existing reservoir dam
• construction of notches
• habitat enhancement
• removal of small weirs and structures
• installation of small measurement structures
• moorland or peatland re-wetting and natural flood management
• construction of fish easements and fish passes, including those for elver and eel

This RPS describes each activity and gives the specific conditions for each. If an activity does not fall under a relevant description, the Environment Agency will not consider it a low risk impounding activity.

You must check if an existing impounding licence covers these activities. If it does, you may need to apply to change (vary) the impounding licence to carry out the intended activity.

You can apply for an impounding licence instead of relying on this RPS if you prefer.

General conditions you must comply with

For the Environment Agency to consider your proposed impounding works as low risk, you must comply with all the ‘general conditions’ in this RPS. This is unless the impounding works are for:

• moorland or peatland re-wetting and natural flood management – in which case general conditions 6 and 7 do not apply
• construction of fish easements and fish passes, including those for elver and eel – in which case none of the general conditions apply

Condition 1

You must consider any relevant environmental objective in:

• River basin management plans: updated 2022 (Environment Agency)
• River basin management planning (Scottish Environment Protection Agency)
• Water Environment (Water Framework Directive) (England and Wales) Regulations 2017
• Water Environment (Water Framework Directive) (Solway Tweed River Basin District) Regulations 2004
• Water Environment (Water Framework Directive) (Northumbria River Basin District) Regulations 2003

Condition 2

You must keep records for 2 years to show that you have complied with this RPS. You must make these records available to the Environment Agency on request.

Condition 3

You must not cause, or be likely to cause, damage to freshwater fish, migratory salmonids (salmon and sea trout) or eel resulting from:

• inhibiting or preventing their upstream or downstream migration
• disturbance of spawn, spawning fish or spawning areas

Condition 4

You must not cause or be likely to cause damage to:

• a designated site or specific designated features in such a site
• protected species

‘Designated site’ means any of the following: 

• a European site (as set out in Regulation 8 of The Conservation of Habitats and Species Regulations 2017)
• a Ramsar site (as set out in Section 37A of the Wildlife and Countryside Act 1981)
• a site of special scientific interest (as set out in Section 52(1) of the Wildlife and Countryside Act 1981)
• a nature reserve established by a local authority under Section 21 of the National Parks and Access to the Countryside Act 1949

‘Protected species’ means any of the following: 

• a species of a kind mentioned in Article 4(2) of Directive 2009/147/EC of the European Parliament and of the Council on the conservation of wild birds or listed in Annex I to that Directive
• a species of a kind mentioned in Annex IV to Council Directive 92/43/EEC on the conservation of natural habitats and of wild fauna and flora
• a species which is subject to a licence under Section 16 of the Wildlife and Countryside Act 1981

There’s guidance on how to search for designated sites and protected species.

Condition 5

You must not have a significant adverse effect on species included in the list of habitats and species of principal importance in England .

Condition 6

You must not carry out any works within 200 metres of the boundary of a type of habitat included in the list of habitats and species of principal importance in England.

Condition 7

You must not carry out any works within 100 metres of a water body that is classified as of ‘high morphological status’. This is defined by the Water Framework Directive (Standards and Classification) Directions (England and Wales) 2015 .

You can get information on the water framework directive status for an individual water body through:

• the Catchment Data Explorer
• the river basin management plan for a region

Condition 8

You must not affect:

• an existing lawful abstraction, including an abstraction or impounding activity exempt from licensing
• any existing lawful uses

Condition 9

You must not prevent any navigation authority from carrying out its legal obligations.

Activity specific conditions you must meet

As well as the general conditions, your proposed impounding works must meet all the specific conditions for the activity for the Environment Agency to consider them low risk.

Maintenance works 

This means maintaining impounding structures, whether it is ongoing or a one-off. 

You must use materials of the same kind as those present in the structure. If the materials have been restricted, you must use a suitable similar material.

You must not: 

• change any dimension of the structure
• change the function of the structure from what it was originally designed to do

Flood prevention measures 

This means constructing erosion protection works, or fixed control or passive structures within the channel, which are only for flood prevention to hold back flood water. 

You must: 

• allow non-flood flows to pass unimpeded
• make sure that the upstream water level is not raised outside of the normal wetted perimeter of the channel under bank full conditions
• make sure that, where fish are present, the structure allows fish to move unimpeded upstream and downstream

You must not permanently change the flow regime.

Temporary works 

This means works that temporarily impound, impede or divert water during construction or maintenance of a structure. 

You must not: 

• have impounding works in place for more than 6 months
• significantly change the downstream flow regime or significantly change the pattern of flow over a structure
• significantly change the water level upstream of the impounding works

Works to an existing reservoir dam 

This means either:

• changing, moving or constructing a spillway on an existing reservoir dam
• installing a wave wall on an existing reservoir dam

You must not:

• change the upstream impounding level
• change the downstream flow regime

‘Spillway’ means a structure that, when a reservoir is full, enables floodwater to pass safely and in a controlled way, over, around or through a dam. A spillway can be:

• part of a dam
• next to a dam

Construction of notches 

This means constructing one or more notches on existing impounding works. 

You must not: 

• construct notches of a combined width of more than 10 percent of the total width of the impounding works and up to a maximum of 60 centimetres in width
• construct notches of a depth greater than 25 percent of the width of the notch up to a maximum of 15 centimetres in depth

Habitat enhancement 

This means placing stones, logs and woody debris for habitat enhancement across parts of the watercourse.

You must use materials that are found naturally where the works will take place.

The works must not: 

• occupy more than half the cross-sectional area of the channel
• be more than 30 centimetres in height

Removal of small weirs and structures 

This means removing small weirs and structures from the watercourse. 

The works must not be more than 30 centimetres in height.

Installation of small measurement structures 

This means installing small water level or water flow or other types of measurement structures. 

The structure must not: 

• be more than 30 centimetres in height
• be in place for more than 12 months

Moorland or peatland re-wetting and natural flood management 

This means blocking gullies, grips or drainage channels for the purpose of:

• moorland or peatland re-wetting
• habitat restoration using natural flood management

The works must not happen where fish are present.

Construction of fish easements and fish passes, including those for elver and eel

This means constructing fish easements and fish passes, including those for elver and eel, on existing impounding works. 

You must not start construction until you have received approval for the works from the Environment Agency. Find out how to get approval for a fish pass.

Things to note

The government has consulted on abstraction and impounding activities moving into the environmental permitting regulations. This RPS relates to an activity that the Environment Agency considers is potentially suitable to be an exclusion under those regulations.

When you must check back

The Environment Agency intends to review this RPS by 1 April  2026.

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

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.

If you cannot comply with this RPS

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

• stop the activity to which this RPS relates
• tell the Environment Agency immediately by emailing enquiries@environment-agency.gov.uk

Contact the Environment Agency

If you have looked at this RPS and you are not sure if your proposal needs an impounding licence, you can get advice using the Environment Agency’s enhanced pre-application service. 

If you have any questions about this RPS, email wrregulation@environment-agency.gov.uk