Although fortifications were built here by the Maccabees in the second century b.c. , King Herod the Great improved on these hugely, transforming them into a magnificent fortified palace, stocked with years' store of food and fitted with enormous cisterns (supplied by flash floods via an aqueduct) to ensure a plentiful water supply.
There were no aqueducts to fill up the cisterns.  
mnli hypothesis: There were no aqueducts to fill up the cisterns.   premise: Although fortifications were built here by the Maccabees in the second century b.c. , King Herod the Great improved on these hugely, transforming them into a magnificent fortified palace, stocked with years' store of food and fitted with enormous cisterns (supplied by flash floods via an aqueduct) to ensure a plentiful water supply.