The Canterbury DHB says it's having to carry out an extra 1000 surgeries a year.

The board was threatened with a $24 million bill over elective surgeries if it did not get over 3000 surgeries booked by Sunday, under its recovery plan.

Since July last year the board's spent over $20 million transferring over 2100 bookings to private hospitals and other DHBs, to meet the targets.

CEO David Meates said the DHB managed to get a yellow status by the end of last week, not a red status, which comes with a penalty.

Mr Meates said the heart of the problem is a shortage of operating theatres, and increasing demand.

He said the Acute Services building under construction will have six new theatres in 2018, but that will only temporarily suffice.

"We'll have closed the gap probably for about a year, maybe two, before we'll be back under pressure again for theatre capacity."