Whatever you do, dont drain it and fill.
NZ has lost most of its wetlands already to development and farming.
Wetlands are homes to many native fish, birds, and other aquatic life.
You should post up some pics of it as I waould be keen to see the area you are talking about.
I manage to spend hours and hours just watching wildlife in wetland areas. Call me a geek if you will, but its what I love to do.