The Environment Agency is warning farmers with private springs, wells and boreholes to check they are taking water legally from the environment.
Farm inspectors are finding a lot of unlicensed abstraction taking place in Devon and Cornwall during routine farm inspections.
Many farms rely on their own private water supply from springs, wells and boreholes.
Farmers could be unknowingly breaching the allowed limit for abstraction without a licence.
Lisa Best, agriculture team leader for the Environment Agency in Devon and Cornwall, said: “All landowners should know how much water they are abstracting and ensure they have the relevant licence if needed.
“Abstracting water without the necessary licence or in breach of your licence conditions is an offence and could lead to enforcement action.
“Taking 20,000 litres of water a day is enough to wash over 100 cars.
“Taking more water than you are permitted could impact on other users and damage the environment.”
The Environment Agency controls how much, where and when water is abstracted through our licensing system.
Anyone taking 20 m3 of water per day or over is required to have an abstraction licence.
Environment Agency farm inspectors have issued 70 actions to farmers over the past two years to install a meter to monitor how much water is being taken and apply for a licence where it is clear one is needed.
Abstraction licences have conditions on them to ensure the environment and the rights of other abstractors are protected.
Climate change and population growth means there will be less available water with a greater demand for it.
By 2050, the amount of water available could be down by 10-15 per cent, with some rivers seeing 50-80 per cent less water during the summer months.
We need to protect the environment by reducing the amount of water we use.