RP19: First flush rainwater diverters and downpipe filters

Find out about eligibility and requirements for the first flush rainwater diverters and downpipe filters item.

How much will be paid

£125 per unit.

Where to use this item

Available for Mid Tier and Higher Tier


  • in areas targeted for the reduction of water pollution from agriculture
  • with a rainwater harvesting system
  • with support from a Catchment Sensitive Farming officer

Where this item cannot be used

  • without relevant advice or permission from the Local Planning Authority

How this item will benefit the environment

It diverts and filters potentially contaminated roof water to keep leaves, debris and other contaminants out of diverters, clean water drains and water storage tanks. This will help provide clean water that can be used for a number of tasks around the farm such as yard washing, instead of wasting potable water supplies.


  • install individual rainwater diverters and filters, wall-mounted diverters or stand-alone diverters (depending on the volumes to be treated) according to the manufacturer’s guidelines
  • make sure that contaminated water is not diverted to a clean water drain or discharged to ditches or watercourses
  • ensure that all work meets relevant British Standards - examine copies of the most up-to-date standards for guidance

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 the Local Planning Authority 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 Local Planning Authority
  • photographs of the existing site
  • written support from a CSF officer

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

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.

Improve water quality

  • collect rainwater from roofs and buildings and use it for tasks around the farm such as yard washing - fitting a first flush rainwater diverter is critical to good quality water
  • know that water diverters improve water quality, reduce tank maintenance and protect pumps by preventing the first flush of water, which may contain contaminants from the roof, from entering the tank
  • use downpipe filters to keep leaves, debris and other contaminants out of diverters, clean water drains and water storage tanks - the work includes the supply and installation of downpipe filters

Agreement holders must also check if restrictions apply to using harvested rainwater in your supply chain. Contact the farm assurance scheme and purchasers of produce.

Historic and archaeological features

  • get listed building consent if used close to a historic farmstead or listed building, as this item may have negative effects on it
  • consider the effect of the item on the fabric and setting of the historic buildings, as well as the nature and historic value of the existing surfaces

Further information

Guidance on implementing a water management plan.

Guidance about the effective use of water on dairy farms.

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 29 March 2016 + show all updates
  1. Information updated for applications in 2016
  2. First published.