NSW's net debt will be wiped out following a bumper budget surplus of $4.7 billion this financial year, Treasurer Gladys Berejiklian says.

The healthy result for 2015-16 is a $1.3 billion improvement on the $3.4 billion surplus flagged in the June 2016 budget. General government sector net debt fell from $5.5 billion at 30 June 2015 to negative $57 million at the same time this year – meaning NSW is in a…