UK Irrigation Association executive secretary Melvyn Kay said: "We need to look over our shoulder at who is or who might take our water away from us. Agriculture is at the bottom of the heap when it comes to allocation and the voice of water in agriculture is weak and fragmented. A stronger voice is needed."
One argument that growers should deploy in policy circles is the economic and social effects of withdrawing irrigation, he added.
"In Suffolk, 90 per cent of agricultural output is irrigated fruit and vegetables. Switching that to cereals would mean not only a fall in annual value from £51m to £11m, but also a fall in the local employment contribution from £13m to £1.7m."
He suggested that growers form abstractor groups, which are a key component of the Environment Agency's overall strategy for water use in agriculture as a mechanism to share water and provide greater water security for the future. "A federation of water abstractors would be a strong voice," said Kay.
He also urged growers to benchmark their water use performance using a tool developed by Cranfield University.
"The more data goes in, the better the picture," he said, "although you can't see other growers' data."
He concluded: "Growers should take responsibility for doing things well before someone else does in a way you may not like."
Picking up the message, Defra research programme manager Dr Dan McGonigle said: "We want to see irrigators involved in the consultation on the water white paper scheduled for next year.
McGonigle added: "Given the recent climate change risk assessment, we will become much more reliant on irrigation."
He stressed that abstraction licences "are about providing incentives to use water more efficiently".
Reservoir Role - Water supply problems
Building reservoirs "should be a no-brainer", said UK Irrigation Association executive secretary Melvyn Kay. "The problem is right now you can't fill them.
"If you did the right thing last year and put one in, you're now stuffed. There are growers in Norfolk who won't be growing potatoes this season simply because they don't have the water in their reservoirs."
Meanwhile, above farm-scale, "it's hard to get new reservoirs past planning", according to South East Water demand forecaster Gemma Avory.