It has been a year since Northern Ireland's 26 councils were reduced to 11 - with the new bodies given wider responsibilities.
Fiona McCandless told the BBC's Inside Business programme the Planning Service was pleased with the transition.
"The councils were sufficiently resourced to deal with the applications transferred to them," she said.
"They had the necessary skills and resources to deal with that.
"Time have proven that the backlog cases that the department previously dealt with have been really significantly reduced.
"The councils now are dealing with the cases that have been submitted, more since 1 April last year."
You can hear more on Inside Business on Radio Ulster at 13:30 BST on Sunday.
The chief planning officer has said the transfer of planning powers to the new super councils has been a success.