Guidance

Installing small-scale monitoring instruments and associated equipment alongside in main river watercourses: RPS 333

Published 11 March 2025

Applies to England

This regulatory position statement (RPS) does not change your legal requirement to obtain and comply with an environmental permit for the flood risk activity of physically installing small-scale monitoring equipment in or near a statutory main river.

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

• your activity does not cause (and is not likely to cause) increased flood risk or impediment to land drainage

• your activity does not cause (and is not likely to cause) pollution of or harm to the environment or harm to human health  

1. Activity this RPS applies to

This RPS applies to the installation of temporary (up to 10 years) monitoring equipment in a statutory main river and associated instrument cabinets and similar on adjacent ground. The need for the equipment must be reviewed within 10 years at the latest. The equipment must be removed as soon as practical if not required, or a new notification made for a further 10 years if necessary.

If you cannot meet these requirements you must apply for a permit.

This RPS does not change your legal requirement to obtain other permissions from any other statutory authority, including other functions of the Environment Agency if relevant, such as water quality or, where required, navigation.

2. Conditions you must comply with

You must:

• keep records to show you have complied with this RPS from when you start using it until 2 years after you finish using it
• make these records available to the Environment Agency on request.
• notify the Environment Agency of every location where the RPS is to be used before equipment is installed by emailing RPS333rivermonitoring@environment-agency.gov.uk

Include the following information in your email:

• the grid reference location of the equipment in the format of 2 letters and 10 digits, for example, ST 58132 72695

• a description of the specific equipment at this location (such as sensor and raised equipment box, trade names of equipment)

• contact details of the operator, telephone or email

Multiple notifications can be made together using a spreadsheet or Geographic Information System (GIS) files. Contact the Environment Agency by emailing RPS333rivermonitoring@environment-agency.gov.uk to make sure GIS formats are suitable.

You must maintain these records along with:

• photographs of the installation once operational, including before and after you restore disturbed ground

• the assessment of potential impacts on protected sites, including a habitats regulations assessment and assessment of potential impacts on SSSI, if relevant 

• information about species licensing, if relevant

• the assessment of potential impacts on other protected areas or protected species, if relevant

2.1 Instruments in a main river watercourse

Before you use this RPS and notify the Environment Agency using this process, you must check your activity meets all the following conditions:

1. The equipment in the river is not bigger than 1.5m x 1m x 0.5m and must not occupy more than 10% of cross-sectional area of the river channel measured to bank top.
2. The equipment is fully and securely attached to the bed or bank. Any equipment using a permanent or semi-permanent raft to support will need to comply with exemption 16 or you must apply for a bespoke permit.
3. The equipment must not impede the structural integrity or function of any other monitoring equipment such as gauging weirs, sensors, or flood level boards.
4. The equipment must not be in place for more than 10 years without a further notification and must be removed as soon as practical if it is no longer required. If you make a new notification you must comply with any changed conditions.
5. The equipment placed on the bed of the river must not be installed within 20m of any culvert or flow control structure within the main river. Note, an adopted sewer or private drainage pipe discharging into a river is not considered to be a culvert for the purposes of this RPS. An enclosed main river watercourse is considered to be a culvert.
6. You must not dredge or excavate the riverbed to install the equipment. If dredging is necessary, then you must register and comply with exemption 24 or apply for a bespoke permit.
7. You must erect a fixed hazard marker on the nearest bank of the main river while the equipment is in place if there is no associated equipment on the bank top. If there is associated equipment present, then this should be clearly labelled as its purpose, operator or owner, and contact details (telephone or email).
8. Your works must not disturb the bed and banks of the main river beyond the necessary minimum, or cause any pollution, including release of suspended solids in the water.
9. Any equipment located where the Environment Agency requires access to carry out work must be removed within 7 days of receiving a written communication and must not be replaced until advised by the Environment Agency. The Environment Agency may remove the equipment if you do not comply or in an emergency.
10. The equipment or associated items such as power cables must not adversely affect any culvert, remote defence, river control works, sea defence or any raised embankment or wall forming part of the bank of the main river.
11. The works must not use vehicles or wheeled or tracked machinery on the bed or bank of the main river. See definition of bank in the things to note section. Any damage to land adjacent to the bank must be made good.
12. Any sensor or sampler using a pump must be screened to prevent eels or other fish becoming trapped.
13. You must not abstract (take) more than 20 cubic meters of water per day from the river. If you need to abstract more, you must apply for an abstraction licence.
14. Structures must be kept free of debris and accumulated matter to the reasonable satisfaction of the Environment Agency.
15. You must comply with conditions set out in this RPS about work in or near protected sites.

2.2 Instrument cabinets  and equipment alongside a main river

Before you notify the Environment Agency using this process, you must check your activity meets all the following conditions:

1. Construction must not adversely affect the bed or bank of the main river (see definition of bank in the things to note section) or cause any pollution, including release of suspended solids in the water.
2. Where ducts are required between the sensor and associated equipment, you must install these to make sure that they cannot break free and do not cause a potential flooding problem.
3. Equipment must not occupy a plan area more than 4m² when constructed in areas liable to flood.
4. When constructing the equipment, you must not disturb the ground more than 1m on either side of the equipment.
5. The equipment or associated items such as power cables must not adversely affect any culvert, remote defence, river control works, sea defence or any raised embankment or wall forming part of the bank of the main river.
6. The equipment must be securely fixed to foundations or a similar anchor which is at least 1m away from the edge of the bank. You must not construct anything other than ducts between the equipment and the sensor.
7. The equipment must not prevent access to and along the riverbank for Environment Agency staff and vehicles.
8. The equipment must not be in place for more than 10 years and should be removed as soon as practical when it is no longer required. If required for longer, then you must make a new notification and comply with any changed conditions.
9. Installation of the equipment must not require any separate reinforcement of the bed or banks, such as concrete bagwork, sheet piles or brickwork.
10. The height of the land surrounding the equipment must not be changed by the construction by more than 100mm. Any excavated material exceeding this must be removed from the floodplain.
11. Any fencing surrounding the equipment must be of open construction comprising post and rail, post and wire mesh fencing of at least 100mm spacing; or post and wire strands.
12. When the equipment is no longer needed you should remove it and restore the riverbank to its previous condition. You must use materials of the same kind as those present for the restoration works.
13. The works must not involve the use of vehicles or wheeled or tracked machinery on the bed or bank of the main river. See definition of bank in the things to note section. Any damage to land adjacent to the bank must be made good.
14. You must comply with conditions set out in this RPS about work in or near protected sites.

2.3 Work in or near protected sites

Before using this process, you must consider potential impacts on protected sites and species. You must consider all parts of your work, including potential impacts from the installation and operation of the equipment as well as the maintenance and access requirements.

If you are a competent or section 28G authority

To comply with this RPS, you must make sure your activity meets the following conditions:

1. There is no likely significant effect on any European site. You must keep a record of the habitats risk assessment (HRA) for inspection if necessary.
2. The activity is not likely to damage any sites of special scientific interest (SSSIs). You must keep a record of the SSSI assessment for inspection if necessary.

3. The activity does not have adverse effects on:

   • other protected species
   • other protected habitats (such as local nature reserves)
   • the countryside or places of special interest

If you are not a competent or section 28G authority

You must not carry out any works in or within 50m of a protected site. If your proposal requires this, then you cannot use this RPS and must contact the Environment Agency about obtaining a permit for your work ahead of any activity planned on site.

See things to note for further information.

3. Things to note

These notes only apply to works affecting main rivers and their flood plains. If you are carrying out work to an ordinary watercourse (any watercourse that is not specifically defined as a ‘main river’), then you must contact the lead local flood authority (upper tier or unitary authority) or internal drainage board (if there is one).

If you intend to carry out similar operations but cannot comply with all the conditions in the RPS, you must apply for an environmental permit. This means that the risks from the proposal at the specific site need more careful consideration through the assessment of a permit application. In these cases, work must not start without a permit.

Definitions used in this statement, particularly ‘bank’ or ‘riverbank’ are the same as those in the EPR, in particular Schedule 25.  

If you need to amend access to the structure, then you may need to apply for a permit or register under exemption 28.  

You must get the necessary and appropriate protected species licence from Natural England if relevant. Read Natural England’s guidance on construction near protected areas and wildlife.

Competent authorities must take action to help protect, conserve and restore the protected habitats and species of European sites and comply with the biodiversity duty.

If your activity might impact on the features of any European sites, you must carry out an HRA. Read the guide on how to carry out an HRA.

If your activity might impact on the features of any SSSI, you must consider the potential impact on the designated habitats, species, or geology of the SSSI, at all stages of the activity. Read the guide on sites of special scientific interest: public body responsibilities.

If you are not sure if your organisation is a section 28G authority, you must seek your own legal advice. Examples of organisations that are not section 28G authorities are:

• The National Trust
• Wildlife Trusts and the Royal Society for the Protection of Birds (RSPB)
• electronic communications companies (code operators)

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.

4. When you must check back

The Environment Agency will review this RPS by 29 February 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 and or circumstances that this RPS relates to have 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.

5. 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 RPS333rivermonitoring@environment-agency.gov.uk

6. Contact the Environment Agency

If you have any questions about this RPS email RPS333rivermonitoring@environment-agency.gov.uk.

Online information is available here Flood risk activities: environmental permits.