Any guest who checks in to the seven-bedroom Heatherleigh hotel on the Isle of Wight is advised to turn off the tap when cleaning their teeth.
They also have no choice whether they want a bath or shower - all the baths have been replaced with showers to conserve water.
Other measures that helped the Heatherleigh to scoop a Southern Water award for water efficiency this year included fitting bags to toilet cisterns to minimise usage on flushing, installing water butts to collect rain from the roof for the garden, and growing drought-resistant plants.
Mother and daughter Mary and Kim Gregory were encouraged to adopt green practices through the local council's Green Island scheme when they took over the Victorian hotel - which has an average occupancy of 85% - in 2004.
Mary says: "We thought, we've got a tiny little hotel, let's go for it. You only have to make very simple changes to get the Green Island award, and we just wanted to be an example to other hoteliers, to say if we can do it, so can they.
"Many guests are looking for environmental awareness when they go on holiday now. We've had families staying who chose us because they saw on our website about our Green Island award."
Replacement of baths with showers cost £5,000, the bags for the toilet cisterns, which cut water used in flushing by one-third, cost £15 in total, and the four water butts cost £500.
Mary says: "I haven't turned the tap on in the garden at all this year. We've had hardly any rain this summer and we've got a water shortage on the island, but we had one rain shower and took 400 litres of water off the roof into our water butts - that's a lot of water that would otherwise have gone down the drain."
For more on green issues go to Caterer‘s Green Zone