RP10: Silt filtration dams or seepage barriers

Find out about eligibility and requirements for the silt filtration dams or seepage barriers item.

How much will be paid

£75 per unit.

Where to use this item

Available for Mid Tier and Higher Tier


  • in ditches in areas targeted for the reduction of water pollution from agriculture and for the reduction of flood risk
  • in conjunction with a Feasibility Study, an Implementation Plan or a Catchment Sensitive Farming (CSF) commissioned design plan agreed with Natural England

Where this item cannot be used

  • on historic or archaeological features or areas of existing wildlife interest identified on the Farm Environment Record (FER), the Environmental Information Map or the HEFER
  • where it will restrict the movement of migratory fish or eels
  • without relevant advice or consents from the Environment Agency (EA) or Internal Drainage Board

How this item will benefit the environment

Silt filtration barriers and seepage barriers will slow the movement of water in ditches, to allow pollutants to settle out. This will help improve water quality and may reduce downstream flooding.


  • complete the constructions as set out in the approved Feasibility Study, Implementation Plan or CSF design plan (Water-Holding Feature Management Plan)

Keeping records

Agreement holders will need to keep the following records and supply them on request:

  • any consents or permissions connected with the work
  • receipted invoices, or bank statements where a receipted invoice is unavailable
  • please see the record keeping and inspection requirements as set out in the Mid Tier manual for more detail

Agreement holders will need to keep the following records and supply them with the claim:

  • photographs of the completed work

Before applying, applicants must seek advice from EA and where relevant the Internal Drainage Board to check if consent is required to carry out the planned work. Applicants will have to send the following with their application:

  • a copy of any advice or consent received from the EA and (where relevant) the Internal Drainage Board
  • photographs of the existing site
  • a copy of the Feasibility Study, Implementation Plan or CSF design plan (Water-Holding Feature Management Plan)
  • written support from a CSF officer

This item can be used on the same area as the following item:

Advice and suggestions for how to carry out this item

The following section gives advice on carrying out this item successfully but does not form part of the requirements for this item.

The Feasibility Study, Implementation Plan or CSF design plan should include site-specific guidance for locating and constructing the barriers. However, it is likely that several barriers will be require for successful slowing of flows throughout the length of the water course.

Design and construction

The design of the structure and the materials used will depend on the conditions set out in the plan. A range of materials could be used which include:

  • timber piling or horizontal planks (with gaps between the boards to allow water flow)
  • stone filled gabions
  • recycled plastic drainage material, for example Aquadyne
  • willow stakes and woven branches for a more natural appearance
  • dams that allow for overflows in the centre (this prevents scouring of the ends of the barrier or dam)

Using willow stakes will help anchor the structure, as they may grow. This style of construction may not last very long so allow time for repair or reconstruction during the agreement.

The main function of the barrier is to slow and filter water flow through ditches or temporary water-holding features, rather than dam and hold water. Other capital items are available to dam or hold water.

Remove trapped silt

Trapped silt should be monitored and removed at least once a year. It must only be disposed of in areas that have been set out in the agreement. The maintenance must be done carefully and regularly to avoid polluting sensitive bodies of water downstream or sensitive habitats on land.

Use this item with other measures

This item should be used as part of a package of measures to reduce surface water runoff and related water pollution problems on farm.

Further information

Catchment Sensitive Farming (CSF) operates in parts of the country where there are water quality issues linked to farming. The scheme provides farmers with free advice and training. See guidance for further information on CSF support.

See the Mid Tier manual or Higher Tier manual to find out more about the scheme and how to apply.

Published 2 April 2015
Last updated 10 March 2017 + show all updates
  1. Updated for 2017 applications.
  2. Information updated for applications in 2016
  3. First published.