Closing twinned locks could waste water

NOT only is the statement from British Waterways to 'double-up' on the narrow locks at Hillmorton on the Oxford Canal causing confusion and comment, but  closing down the twinned section of  locks could also waste water not save it.

Ralph Freeman writes that in a single lock there is a 50% chance the lock is set for you and so you do not waste water. With a duplicate pair of single locks that changes. There is only a 25% (1in 4) chance the lock is against you. For instance if you are locking up the only time you waste water is if both locks are full.

No water wasted

If the left hand is empty, or the right hand is empty or both are empty then no water is wasted, in you go.

So by shutting one of each of the pair of locks British Waterways may be increasing water wastage by 25%.