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Low risk impoundment
Our regulatory position and guidance on when you
need to apply for an impoundment licence
Version 1
March 2012
If you comply with the requirements below for a low risk impoundment, we
will not expect to pursue an impoundment licence application.
Introduction
This document is about impoundment licensing. It sets out how we will regulate low risk activities.
We have a long-term aspiration to restore degraded rivers, which is supported by the Water Framework
Directive. Where structures are considered to be essential, this document will help you to minimise the
effect on flood risk or on the ecology, fish migration, morphology and look of a river.
What is an impoundment?
An impoundment is a structure within inland waters 1 that can permanently or temporarily change its level or
flow. This includes dams, weirs, fish passes, hydropower turbines, sluices, penstocks, culverts, lock gates,
retaining walls, flumes, reservoir embankments and temporary diversions during construction work.
What is the Environment Agency's role?
We have responsibilities 2 to maintain and improve our rivers by balancing the needs of people and the
environment, making sure that any impoundment activity does not lead to deterioration in the quality and
ecological condition of waters. Constructing or altering, which includes rebuilding or removing an
impoundment, can change the flow, level, ecology and look of rivers. Your activity can also affect others
who use or rely on the water. It is our role to manage these changes through a system of licensing during
the lifetime of the works.
Do I need an impoundment licence?
By law 3 you must have an impoundment licence before you start to construct, alter, repair or remove an
impoundment structure, even in an emergency. However, we recognise that some of these activities have
little impact on the flow or levels of water even when there is less water in rivers. These impoundments
have no or little impact on the environment and other water users, so we will not pursue a licence
application for these activities. You can still apply for an impoundment licence if you prefer to have one.
You may need to do this for some accreditation schemes.
1
Inland water is a lake, river, stream, pond, reservoir etc that is linked to the water network.
Under the Water Resources Act 1991 (as amended by the Water Act 2003), Environment Act 1995 and the Water
Framework Directive (2000/60/EC).
3
Under Section 25 of the Water Resources Act 1991.
2
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What happens if I don't have a licence?
It is your responsibility to make sure that you follow this guidance and apply for a licence if and when you
need one. If you don’t have a licence and cause detriment to lawful users of water or to the environment,
we may ask you to apply for a licence and take legal action against you. We may have to remove any
impoundment you have built and you may have to pay for this.
For a more detailed explanation of how we approach enforcement, please see our guidance on
enforcement and civil sanctions.
Other consents, permits and legislation
It is your responsibility to make sure that you have any other permits or permissions for your proposal. For
example, you may need an abstraction licence, planning permission, approval for a fish pass under the
Salmon and Freshwater Fisheries Act 1975 or a licence for European Protected Species under
Conservation of Habitats and Species Regulations 2010.
You are likely to need a Flood Defence Consent for most structures or work in or near a watercourse.
Please contact us on 03708 506 506.
You will need to discuss your proposals with other organisations, and sometimes get their permission.
Please use the table in the appendix to find out which organisations you need to contact. Please be aware
that by not contacting the relevant organisation, such as Natural England about work in a Site of Special
Scientific Interest, you may be committing a wildlife offence.
Hydropower and this document
You must have an impoundment licence for turbines installed on or within a weir, because they significantly
modify the flow over the weir and can carry significant risks to the environment. The licence will consider
and address these potential impacts.
If you are maintaining, altering or installing a weir to provide an improved flow to your hydropower turbine,
you may need to apply for an abstraction and/or impoundment licence depending on the site configuration.
Please talk to us or refer to our hydropower web pages for further information on the type of licence you
may require.
For more information
Please contact us if you are unsure whether you need a licence, bearing in mind it can take up to four
months to determine an application. You can call our National Customer Contact Centre on 03708 506 506
or email us at [email protected].
Links to other documents
You may wish to view the following links for further guidance on a range of water related practices.
•
River weirs - good practice guide (Defra/Environment Agency 2003) (PDF, 8.6MB)
•
Fish Pass Manual (PDF, 9.76MB)
•
Living on the Edge a guide to the rights and responsibilities of riverside occupation
•
Water Framework Directive information on the Environment Agency website
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Annex 1
Use the following section to help you decide whether you need to apply for an
impoundment licence.
If you conclude that you do not need to apply to us for a licence, you should keep a copy of your checklist
for your own records. It is also evidence of a proper assessment that you do not need to have a licence.
You may still need to contact some of the organisations listed in the appendix.
Step 1 – Is there already an impoundment licence for the structure?
Before you start work on an existing structure you will need to find out:
•
if there is a licence already issued or going to be issued;
•
who owns the structure and seek their permission to do the work or take over the licence.
We can help you do this.
Use the following table to find out what steps to take:
Existing licence
in place?
Alter the structure
Rebuild the structure
Yes
Check whether your proposals can be done
within the terms of your existing licence. If not,
you need to apply to us to vary your licence.
Remove the structure
Apply to us to revoke your
licence.
If we have served notice requiring impoundment
solely for the purpose of screening or passage
for eels, you will not have to vary your licence.
No
Use this document to
decide whether you
need to apply for an
impoundment
licence.
Use this document and
consider it as a new
structure.
Use this document to decide
whether you need to apply
for an impoundment licence.
Step 2 – Is your proposal exempt?
There are several statutory exemptions where an impoundment licence is not needed. These are:
•
works constructed without a licence before 1 April 2006, except when a notice is served under section 3
of the Water Act 2003 requiring application for a licence;
•
where a navigation, harbour or conservancy authority constructs any new impoundment, alters an
existing impoundment or obstructs or impedes the flow of inland waters in the course of its statutory
functions;
•
where the impoundment is authorised by a drought order or drought permit;
•
where the persons doing the works are Crown exempt;
•
where structures are authorised by an alternative statutory provision (for example an Act of Parliament);
•
works constructed (or altered) in England by a water company that are authorised by a Development
Control Order;
where the Environment Agency serves notice requiring impoundment solely for the purpose of
screening or passage for eels.
•
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Step 3 – Will your proposal result in a significant change in the flow or level of the
water?
You need to consider how your proposal will change water flow or level. The checklist in Step 5 will help
you investigate the impacts of these changes on the environment or other water users.
Impoundments, or alterations to them, can:
•
alter the flow going downstream, so there might be less water available for others or the environment;
•
change the pattern of how the water flows over a structure, so that areas can dry up in low flows;
•
change water level and look of a river.
If your impoundment, or removing it, could cause a significant change in the water level or flow, you will
need to apply for an impoundment licence. For example, building a new weir or adding structures such as
hydropower turbines, sluices, penstocks and lock gates may cause a significant change in water level or
flow.
Step 4 – Is your proposal low risk?
We recognise that some activities are considered 'low risk' and have little impact on the environment and
other water users and rights. Good design and consideration when planning your proposal can ensure that
it won’t cause detriment to the environment, protected rights and other lawful water users. We don’t expect
to pursue an application for these proposals. Please remember, you still need to check if an existing
licence covers these activities and whether you need to obtain another permission.
The examples below illustrate low risk proposals. Some of the proposals in the list aren’t impoundments
according to the legal definition, but people often ask us if they need a licence so we have included them
here.
We will not pursue an application for:
New activities
•
Fish easements or passes 4 that have formal written approval by the Environment Agency and do not
significantly affect the distribution of flow over the weir.
•
•
Placing a notch in a weir to encourage fish migration.
Placing woody debris across part of the channel to diversify flows.
•
Flap valves that only operate during flooding.
•
Fixed control or passive flood prevention structures within the channel that only hold back flood water.
Structures with movable gates or sluices will require an impoundment licence.
•
Small measurement structures, such as v-notch or small rectangular weirs.
Maintaining an existing structure
Maintaining a structure, whether it is ongoing or a one-off maintenance, relating to the upkeep, care or
preservation of the structure. For example:
•
sluice refurbishment
•
•
re-pointing (block work structures)
repairs, for example to expansion joint, stone pitching or bank/wall
•
void filling ('solid' structures)
•
managing vegetation
•
de-silting
4
Fish passes and fish easements are a variety of works or modifications that help fish migrate up or downstream.
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•
re-positioning (rock, rubble or block work bank protection structures)
•
replacing elements that do not contribute to phased replacement of the whole structure
•
•
re-facing
skimming/covering
•
blockage removal, including screen clearing
•
embankment grouting.
Diversion works
•
Works that temporarily divert water in the immediate vicinity during construction or maintenance of a
structure and do not affect any other water users, rights or the environment.
Emergency impounding
•
Emergency impounding works or changes to the impoundment to reduce or avoid an immediate threat
to human life, property or the environment. This only applies to works carried out during the emergency.
Other activities
•
Any activity outside the channel, for example on top of the river banks, such as installing or maintaining
bridge supports or flood defences.
•
•
Work in the river, parallel and adjacent to the bank that doesn’t significantly narrow the channel, for
example installing sheet piling, rip rap, block work and rock revetments for erosion protection.
Installing a wave wall on an existing reservoir dam that is not intended to impound any extra water.
•
Increasing the height of spillway sidewalls (that does not alter the impounding level).
•
Altering, moving or constructing a spillway without increasing the impounded level or changing the
downstream flow regime to the detriment of the environment.
Step 5 – Can you complete the checklist?
Use the checklist below to help you decide whether you need to apply for an impoundment licence. The
notes give extra information to help you answer the questions.
If you answer yes to any of the questions, you may have to apply for an impoundment licence. If you
answer no to all the questions, you will not normally need to apply for an impoundment licence.
If you are unsure about any questions, please contact us. We may suggest you employ a consultant if we
cannot provide the extent of work needed. You should keep a copy of your checklist for your own records.
It is also evidence of a proper assessment that you do not need to have a licence.
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Note
Assessment checklist
1
Do surveys reveal any existing abstractions, including unlicensed ones,
which may be affected by the proposal?
2
Are there any other water users or riparian rights or interests that may
be affected?
3
Will the changes cause parts of the weir to suffer significantly reduced
flows?
4
Is the proposal within, or likely to have an impact on a Site of Special
Scientific Interest (SSSI) or Special Area of Conservation (SAC),
Special Protected Area (SPA) or Ramsar site?
5
Does the proposal affect protected species (not fish) that may live at the
site or elsewhere in the catchment?
6
Are planned changes in river flow likely to cause significant change to
invertebrate habitats?
7
Are planned changes in the river flow likely to cause a significant
change in the macrophyte and diatom communities?
8
Will the proposal impact on either the up or downstream passage of fish
(including eels) in the river?
9
Will the proposal impact on any fish spawning or nursery areas?
10
Will the proposal cause sediment movement or deposition to be
substantially altered above or below the site? Will pollutants be
discharged or mobilised into the river during construction and/or
operation?
11
Is the proposal likely to significantly increase river turbidity or
significantly alter movement of sediment?
12
Does the scheme involve construction of a new raised reservoir with the
capacity of 25,000 cubic metres or more?
13
Will the proposal cause erosion of the river banks up or down stream?
Yes
No
Notes
1. Consider whether any abstractions within the area of impact of the proposal will be affected by your
impoundment. You can get information on abstractions from us. You should discuss your proposal with
any affected party.
2. Any proposal will have to consider the other water users and those with riparian rights, interests or
ownership within the area of impact. This includes land owners, canoeists, boaters, anglers, owners of
fishing rights, water companies, utilities infrastructure, hydroelectric power operators and the
Environment Agency. You could affect their property, pipelines, inlet or outlet structures (which could
affect water quality), telegraph poles, bridges, measuring equipment etc.
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3. Causing part of a weir to suffer significantly reduced flow can affect the channel bed, the stability of the
weir and its amenity value.
4. To find out if you are in a SSSI, SAC, SPA or Ramsar site, use:
o
Natural England’s Nature on the Map website in England
o
the Countryside Council for Wales (CCW) interactive map of protected sites in Wales.
Sites of Special Scientific interest
Your proposal is likely to affect a SSSI if:
•
- it is in the site
•
- the proposal alters the river flow through the site
•
- it is an obstacle to fish migration.
If your proposal is likely to affect a SSSI, you will need to find out whether the proposal is likely to damage
the site, considering why it was designated as a SSSI. You must tell the CCW or Natural England about
any work that may damage a SSSI.
Special Areas of Conservation
There is more information on all SACs in the UK on the Joint Nature Conservation Committee (JNCC)
website.
Your proposal is likely to affect a SAC if it would remove or change the vulnerable natural habitats the site
was designated for. If your proposal is likely to affect a SAC, you will need to apply for an impoundment
licence. We will formally consult CCW or Natural England to make sure there will be no adverse effect on
the SAC
Special Protected Areas
There is a list of all SPAs in the UK on the JNCC website. Your proposal is likely to affect an SPA if it
removes or changes natural habitats that are important to the rare and vulnerable birds the site was
classified for. If your proposal is likely to affect an SPA, you will need to apply for a licence. We will formally
consult CCW or Natural England to make sure that there will be no adverse effect on the SPA.
Ramsar sites
There is a list of all Ramsar sites in the UK on the JNCC website. Your proposal is likely to affect a Ramsar
site if it removes or changes natural habitats that are important to the rare and vulnerable wetlands that the
site was classified for. If your proposal is likely to affect a Ramsar site, you will need to apply for an
impoundment licence. We will formally consult CCW or Natural England to make sure that there will be no
negative effect on the Ramsar.
5. You can find information on protected species in Wales on the CCW website. You can get information
on protected species in England on the Natural England website.
If a European protected species is likely to be affected by your proposal, you may need to get a protected
species licence from Natural England or the CCW before deciding whether you need to apply for an
impoundment licence.
6. Please contact us on 03708 506 506 if you need more information about invertebrate habitats.
7. Please contact us on 03708 506 506 if you need more information about macrophytes and diatoms.
8. If the proposal could potentially obstruct fish migration, you will need to apply for an impoundment
licence. For a weir in a river frequented by migratory salmon or sea trout, you will also have certain
obligations to fish passage under the Salmon and Freshwater Fisheries Act 1975 or for a weir in rivers
where eels may be present under the Eels (England and Wales) Regulations 2009.
9. If the proposal is expected to affect fish spawning or nursery areas, you will have to apply for an
impoundment licence.
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10. Developers should not use toxic chemicals for maintenance, and should take measures to avoid spills.
Developers must not discharge silt or other waste.
11. You will need to prevent solids beings discharged and comply with the:
o
Suspended Solids Standards in the EU Freshwater Fisheries Directive;
o
Water Framework Directive ‘no deterioration’ objectives.
12. If the reservoir will have a capacity of 25,000 cubic metres or more, it may qualify as a statutory
reservoir, and require design and inspection. The Flood and Water Management Act, when enacted,
will reduce the capacity to 10,000 cubic metres. Please see our reservoir web pages for the latest
details.
13. If you remove, partially remove or lower a weir, sediment that has built up behind the weir may move
downstream. This can cause erosion of the banks upstream or downstream. The extent of this will
depend on the current stability. For example, sandy banks will erode but concrete channels won’t.
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Appendix
Even if you do not need an impoundment licence, you may still need to contact other organisations to
discuss your proposals. If you are not applying for a licence, then you will need contact the relevant
organisations yourself. If you are applying for a licence, we will contact these organisations on your behalf.
Please use the table below:
If your proposal…
Then…
might impact on the archaeology, heritage,
aesthetic or amenity value of the structure or
is a listed structure or Scheduled Ancient
Monument
You will need to contact English Heritage in England or
Cadw (Welsh Government’s historic environment
service) in Wales.
is within, or alters the flow through, a Local
or National Nature Reserve
You will need to contact the Local Records Centre or
relevant local authority. You can get a map of all
national and local nature reserves from:
Natural England’s Nature on the Map website in
England
the Countryside Council for Wales (CCW) interactive
map of protected sites in Wales.
The reserves are managed by different authorities,
including local governments.
might not meet the objectives of landscape
protection of an Area of Outstanding Natural
Beauty (AONB)
You will need to contact the relevant local authority.
You can get a map of Areas of Outstanding Natural
Beauty from:
Natural England’s Nature on the Map website in
England
the Countryside Council for Wales (CCW) interactive
map of protected sites in Wales.
could affect a National Park
You may need to get advice from the relevant
authority. Each national park has its own authority,
which also acts as the planning authority. Find out
more on the National Parks website.
could affect a public footpath or conservation
area
You need to contact your local council for advice.
Conservation Areas are designated by local authorities
and approved by the Government. You may need
Conservation Area Consent from your local planning
authority. You will need to provide a Design and
Access Statement with your planning application to
explain design issues.
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