Farmers must find a champion to fight their corner and help secure a fair share of water for agriculture.

The alternative was a future where supplies were increasingly expensive, unreliable and scarce, said Jerry Knox, principal research fellow in irrigation and water resources at Cranfield University.

Speaking at a recent Water and Agriculture Conference, hosted by the Suffolk Agricultural Society at Ipswich, he said: “Agriculture has lots of champions, but they all tend to be commodity focused.

“Water is not a commodity, it is a resource. Somehow we need to get the different farming organisations and stakeholders to work out a common way forward.”

East Anglia was home to more than 60% of the nation’s irrigated farmland, delegates were told. More than 1000 agribusinesses across the region used irrigation to produce 30% of the potatoes and 25% of the fruit and vegetables supplied to supermarkets.

Although irrigation accounted for only 1% of the country’s total water use and just 4% of crop area, Dr Knox said it helped to generate 20% of crop value. “Irrigation is an essential part of the rural economy,” he added.

“Water is not a commodity, it is a resource.”

But rising demand for water, coupled with climate change, meant three in every four farms were now in areas which were either over-licensed or over-abstracted. Most under pressure were north Essex, east Suffolk and parts of Cambridgeshire.

Producers faced a stark choice, said Dr Knox. They had to work together to form abstractor groups, in an effort to increase water security, or face an uncertain future.

Farmers should also consider joining forces with other businesses that relied on water. “Leisure centres and golf courses are in a similar predicament.”

Establishing a centre of expertise to promote best practice and efficient water use would also help secure a fair share of water for agriculture. But the farming industry had to take ownership of the concept, which was why a champion was needed.

“We thought we would be running out of land – instead we are running out of water.”

Farmers will have to take their “water footprint” as seriously as their carbon footprint, delegates were told.

As demand for food increased, so would the amount of water used to produce it, said environmental consultant Fred Pearce. “We thought we would be running out of land – instead we are running out of water.”

Water would become much more expensive and more intelligent ways of irrigating crops would be needed. “We can manage without oil, but none of us – not even for one day – can manage without water.”