Three-quarters of businesses in the east of England were found to lack a sustainability initiative, compared to Wales where almost two-thirds of firms had a green policy in place.
Ian Barker, head of water resources at the agency, said: "It is vital that businesses remain committed to best practice through this difficult economic period.
"Whilst we appreciate the strains that company finances are under, the majority of efficiency measures actually reduce costs by reducing water and energy use."
Last week, it was reported that npower has launched a new service to help businesses make better-informed energy-buying decisions.
The Risk Navigator is web-based and gives companies breaking news on price movements.
Click here to run an energy price comparison, and see if you could be paying less for your gas and electricity.