I suspect that school toilets (or any other public building) that have no water for flushing or washing hands are a serious health risk. At home the risk of spreading germs is significantly reduced as there are fewer individuals, and it is easier to conserve water. In addition the preparation of school meals is likely to be affected and schools do not have resources to phone out for pizzas for 200 pupils.
I'm no expert in such matters, but to instantly accuse the 'pc brigade' (in this case the teachers at the school) of not knowing what they are doing seems a little off. Perhaps it is you and not they who have not fully thought through the actions they have taken.