Supporting guidance for Water-use Efficiency – Irrigation Lagoon

Date published: 20 January, 2017

For recent changes to this guidance, please see the bottom of the page.

This item provides a contribution towards the costs of installing a lined lagoon for collecting and storing water to be used for irrigation purposes.

Some rivers and burns in Scotland can in dry summers suffer from exceptionally low water levels with a number of burns running dry and so causing significant damage to aquatic life within the river.

An irrigation lagoon will allow water to be abstracted over the winter and stored and so help reduce the need to take water from burns and rivers at times when the water levels are low thus helping to protect the aquatic life within the river.

  • if an abstraction from the water environment is required to fill the lagoon then an authorisation will be required from the Scottish Environment Protection Agency
  • filling the lagoon should be timed to cause minimum impacts on the water environment. This will usually be during high flows, preferably in the winter, but the Scottish Environment Protection Agency should be contacted by email at for advice to ensure that environmental standards for the site are being met
  • the lagoon must not be directly connected to the water environment (i.e. there should be no dams or other works which hold back flows in wetlands, rivers, lochs and estuaries)
  • where the lagoon is not connected to the water environment no authorisation will be required from the Scottish Environment Protection Agency, if there are any doubts it is best to speak to the Scottish Environment Protection Agency at an early stage
  • it is important to check with the local planning authority to investigate if planning permission will be required
  • where a proprietary lining is to be used (as opposed to a clay soil liner), a receipt for the liner will be required. This will be used to prove that a liner has been incorporated and may be checked as part of the process of verifying costs

Where the lagoon is capable of holding 25,000 cubic metres (due to drop to 10,000 cubic metres) or more of water above the natural level of any part of the surrounding land then it will be captured under reservoir safety legislation.

Reservoir safety in Scotland is covered under the Reservoirs (Scotland) Act 2011 which is regulated by the Scottish Environment Protection Agency.

Where the reservoir is likely to exceed the 10,000 cubic metres threshold it is advised to speak to Scottish Environment Protection Agency at the early planning stage.

The reservoir construction must comply with the Construction, Design and Management Regulations(CDM).

The Thinking about an irrigation reservoir booklet provides a useful guide to planning, designing and constructing a water storage reservoir.

Section Change
Benefits Further guidance has been added to this section
What needs to be done? Bullet point added regarding timing of filling the lagoon
Design guidelines References to Reservoirs Act 1975 removed