Here is graph from the recent Westpac Bank Economic Overview. It shows how closely correlated the New Zealand and Australian economies are with regard to the % of GDP from the quake related reconstruction in New Zealand and the iron ore boom in Australia.
The Canterbury rebuild will peak around late 2016 and into 2017 although growth after this point will be fairly subdued. The falling exchange rate and lower interest rates will act as a buffer but the dwindling rebuild with become a drag on GDP in New Zealand.
Australia has also experienced a slow down with a reduction in mining construction amid falling iron ore prices. To stimulate growth the Reserve Bank of Australia has cut the cash rate from 4.75% to 2.0% and the Australian dollar has fallen about 30%. However high unemployment and low business and consumer confidence have been prevalent in the economy and growth prospects are very modest for the next few years. This is similar to what New Zealand can expect.