The series creators wanted to film the series in Hawaii. But another little dino project was also filmed on that location: Spielberg’s Jurassic Park. Spielberg also happened to be a producer of Terra Nova. He didn’t want Terra Nova to be filmed on Hawaii out of fear it would be too similar to Jurassic Park and he practically vetoed it away. This forced the creators to look elsewhere and i believe they settled on New Zealand. The problem however was that it was massively more expensive to film a series there. The costs eventually canned the series.