Anyone who takes more than 4,000 gallons of water per day from a river or stream needs to obtain a licence from the Environment Agency.

Since a waterwheel or any other hydropower generator temporarily diverts free flowing water, such an Abstraction Licence must be obtained.

Why is Hydropower not Exempt

Although hydropower offers many environmental benefits, it can also have serious negative effects if care is not taken. Oils and greases used in maintenance of a hydropower generator could pollute the water, the movements of fish can be limited and they and other life can be killed by turbines. Finally, hydropower systems can affect land drainage and potentially increase the risk of flooding.

What is an Abstraction Licence

An Abstraction Licence gives the holder the right to take a fixed amount of water daily from a particular inland or underground water source for a time-limited period (usually 12 years).
After 12 years the licencee must reapply proving that they still need the water, that the water taken has been used efficiently, and that there have not been negative effects to the environment caused by the abstraction.

Abstraction Licence Costs

When applying for an abstraction licence an application charge of £135 (at time of writing) is payable together with any private consultancy fees, statutory advertising, and other costs incurred by the Environment Agency in processing the application.

There is also a subsistence charge payable on 1st April each year which depends on a number of factors: the volume of water to be taken, the source of the water, the season in which it is taken, the loss (a measure of how much water is wasted), and the UK region.

Calculating Annual Abstraction Licence Costs

SUC
Each UK region is given a Standard Unit Charge – from £24.86 per 1,000 cubic metres (*) of water per year for Northumbria, down to just £10.71 per 1,000 cubic meters per year for Yorkshire.
(*) 1,000 cubic metres of water is equivalent to just under 220,000 gallons.

Volume
The amount of water licenced to be abstracted each year (measured in units of 1,000 cubic metres).

Source
The Source Factor is determined by the origin of the water – for example, 0.2 for tidal water, 1.0 for groundwater.

Season
Water is far more scarce in the summer than in the winter, therefore the Season Factor for summer (1.6) is ten times that for winter (0.16). If water is to be taken all year, the season factor is 1.0.

Loss
The Loss Factor is used to take into account how much water is lost because it was abstracted – for example, crop spraying leads to heavy losses, but large scale hydropower plants lead to minimal losses. Hence the loss factor for 5MW+ hydropower plants is just 0.003 compared to 1.0 for crop spraying. Abstraction for domestic size hydropower generation is considered to be low loss and so has a loss factor of 0.03.

These costs are all explained in far greater detail in the Environment Agency Scheme of Abstraction Charges (PDF) document which can be viewed here.

Further Information

The Environment Agency provide a selection of Abstraction Licence guides. The main one is Abstracting Water – A Guide to Getting Your Licence (1MB PDF) which is not a bad introduction.

Of more use is: Hydropower – A Handbook for Agency Staff (326KB MS Word Doc) – a guide prepared to advise Environment Agency staff considering hydropower proposals.

If you would like to contact the Environment Agency directly to ask about a planned hydropower system you can email enquiries@environment-agency.gov.uk or call 08705 506506.

If the complexity and cost of going through this process for a one-off single hydropower project is daunting, there are experts out there who can do all the work for you as a comprehensive service. Try Hydro Generation a division of Segen Ltd and (at the time of writing) the only UK company to have full accreditation under the Low Carbon Buildings Programme for micro-hydro installations.