.. many operators reduce water carried..have you also looked at removing the duty free carts...that is also an area ( for cabin crew) weight can be saved. especially out of Australia where you can leave it at DFS...
also to ease calculations look at the price of fuel per tonne.. all plans have a delta burn per delta tonne of ZFW - at current prices it is 835 USD per tonne of fuel. so if you carried 300 kg less water you would save about 250 dollars per sector. maybe. .. but would your company also reduce the fuel surcharge the same percentage?? I expect not. it makes it hard to justify fuel surcharges I if you find ways to save it.. food for thought only - every tonne of fuel you save also saves four tonnes of co2 emissions as well.
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