Ensuring water supply resilience for horticulture

Learn more about water auditing, planning for unexpected supply interruptions and how to use abstraction licences efficiently and flexibly.  

This information was last updated in 2019.

Auditing business water use

To support licence applications and to demonstrate an ongoing need for water, you need to understand your business’s supply need and how it varies through the year.

A water audit will help on both counts.

A water audit can also demonstrate efficient water use and help you identify where water could be saved or recycled.

The audit should include:

• records of weekly/monthly water use by different production areas
• options for harvesting or recycling
• actual and potential water storage capacity
• types of irrigation systems used and their relative efficiency
• how crop water demand is assessed, and
• a detailed summary of measures in place to avoid water pollution.

How long can your businees cope with an interrupted water supply?

Consideration should also be given to how long the business could cope or the level of crop damage that could be tolerated if the water supply was interrupted.

Interruptions can be the result of a temporary emergency, licence restrictions imposed by the regulator or drought conditions.

Audit findings may reveal that you need storage, or an alternative water source, or a mitigation strategy to preserve crops when water is limited.

Headroom calculations

Adding ‘headroom’ to an abstraction licence can help protect against uncertainties. Applying for a licence which allows abstraction of more water than your business typically uses acts as an insurance policy against dry weather or drought, when water usage is often higher than average. Sufficient headroom in license volumes is important if businesses are to cope during dry years.

In recent years, the Environment Agency has revoked unused licences or reduced underused licences to manage the potential risk of over-abstraction on the environment. A software tool such as D-Risk (www.d-risk.eu) can help you assess abstraction-related risks to your crop production and guide the calculation of how much licensed water abstraction and headroom you need. It can also help gauge resilience to drought or the impact of reduced headroom on licensed volumes.

Supply interruptions and diversification

Supply interruptions are always a possibility, whether caused by a burst pipe, the drying of a shallow borehole or official restrictions on abstraction during periods of dry weather. You should know how quickly a supply interruption would become critical for your businesses and have a plan in place to mitigate the effects as far as possible.

The ability to switch supply could be a lifeline.

Businesses using mains water could consider putting in a borehole to abstract groundwater, and those abstracting for irrigation directly from watercourses may find that stored water in a winter-filled reservoir provides a more reliable source in summer months when the usual supply may be restricted. Likewise, the ability to switch to mains supply when unable to abstract water could help avoid damage to crops.

License trading

In England, it is becoming easier to trade spare licensed water volume between licence holders temporarily or permanently.

Typically, this involves two parties abstracting from the same source. One takes less than their licensed amount and the other takes more.

• If a part-trade of licence is agreed, then the donor and recipient must ensure that the total abstraction does not exceed the licensed volume.
• The recipient of the extra volume is bound by any abstraction restrictions on the original licence.
• Trades require approval from the EA and may be restricted to past usage rather than full licensed volumes.

It usually easier to get permission for trading of surface abstraction than trading of groundwater; more complicated analysis may be required to establish that a groundwater licence trade is feasible.