RP17: Storage tanks underground

Find out about eligibility and requirements for the storage tanks underground item.

This item is part of Capital Grants. You must read the Capital items: guidance for applicants and agreement holders to understand the rules and how to apply.

How much you’ll be paid 

£441.98 per cubic metre (m3).

How this item benefits the environment

The underground storage tank will collect and contain rainwater, helping to keep clean separate by collecting and containing it. This provides free clean water, which may be suitable to use around the farm for tasks such as yard washing.

This item can help you protect, recover and improve biodiversity on your land.

Where you can use this item

You can only use this item with support from Catchment Sensitive Farming in areas targeted to reduce water pollution from agriculture.

Catchment Sensitive Farming provides advice where there are water quality or flood risk issues linked to farming.      

You must get advice from the local planning authority to check if consent is needed.

You cannot use this item:

  • without relevant advice or permission from the local planning authority
  • to collect slurry or contaminated water

Your Historic Environment Farm Environment Record (HEFER) will identify:

  • scheduled monuments
  • registered parks and gardens
  • registered battlefields
  • Selected Heritage Inventory for Natural England (SHINE) sites

You must not use this item on scheduled monuments, registered parks and gardens or registered battlefields without written approval from Historic England.

You must not use this item on SHINE sites without written approval from your local authority historic environment adviser.

What you must do to use this item

You must:

  • agree where to install the tank and pump with your Catchment Sensitive Farming adviser
  • follow the manufacturer’s instructions when installing the tank and pump
  • use tanks made from either glass-reinforced plastic (GRP) or pre-cast concrete
  • cover the tank with concrete

Evidence you must keep 

You must keep written support from your Catchment Sensitive Farming adviser and provide it with your application. 

You must also keep and provide with your claim:

  • photographs of the completed work
  • any consents or permissions connected with the work

You must also keep and provide on request: 

  • receipted invoices or bank statements where a receipted invoice is unavailable
  • photographs of the site before works start

Read the record keeping and site visit requirements in the Agreement holder’s guide: Capital Grants, Higher Tier capital grants and Protection and Infrastructure grants for more information.

Other items you can use with this item

You can use this item with these items:

RP16: Rainwater goods

RP18: Above ground tanks

RP19: First flush rainwater diverters and downpipe filters

Advice to help you use this item

The following advice may help you to use this item, but you do not have to follow it to get paid. It’s not part of this item’s requirements.   

British Standards  

Check to make sure the work meets relevant British Standards. 

Installing the storage tank

The work normally includes:

  • installing the tank and pump
  • a site excavation
  • creating a hardstanding or concrete base for the tank
  • installing connecting pipework

Managing the water

Make sure that contaminated water does not mix with the clean rainwater collected while the work is taking place .

You must also check if restrictions apply to using harvested rainwater in your supply chain. Check with your relevant farm assurance scheme and purchasers of your produce to confirm.

Using tanks on a high-water table

These tanks are not suitable in ground with a high-water table unless further structural work is carried out to prevent the tanks from floating. You should seek advice from the manufacturer before installing.

Historic and archaeological features

You may need listed building consent if used close to a historic farmstead or listed building, as this item may damage it.

You should 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.

 Effective use of water on dairy farms

Read about the effective use of water on dairy farms on the Agriculture and Horticulture Development Board (AHDB) website.

Updates to this page

Published 2 April 2015
Last updated 3 February 2025 + show all updates
  1. General improvement for clarity.

  2. Added in links to Capital Grants manual as this option is now available for Capital Grants

  3. Information updated for applications in 2016

  4. First published.