I totally agree with you Howard.
Instead of cutting the volume of cisterns, the saving in water could probably have been achieved by maintaining the requirement that the flush mechanism should be of a siphon flush type rather than allowing the use of the greatly inferior flapper valve type flush, which as it relies on the integrity of a seal is prone to leaking (and they always do as soon as there is a little limescale build up). The water wasted as a result of these mechanisms is colossal.
Now I know that it was Brussels who imposed this change to the regulations, but in this case they were completely wrong. They should have obliged all of the EU to ban the sale of the flapper valve type flush and made the siphon flush compulsory. Then maybe we could have kept our 9 litre cisterns.