Food and drink manufacturers have cut their water use by 14.4% through a best practice regime created by the sustainable organisation WRAP.
The Federation House Commitment (FHC) ensures operator's improve water recovery and re-use. The scheme also improves cleaning-in-place, dry cleaning operations and fits more efficient taps and toilets.
Nearly 280 UK sites have signed up to the voluntary agreement.
Dr Liz Goodwin, CEO of WRAP said: "These findings are evidence that signatories to the Federation House Commitment are taking actions that are having a positive impact on water use. These results are helping to make a considerable contribution towards meeting the whole industry target of 20% by 2020."
Between 2007 and 2011 enough water was saved to fill around 2,400 Olympic-size swimming pools.
Goodwin added: "The decrease in water use is particularly pleasing given that production at these sites increased by 10.7% over the same reporting period."