Coastal Restoration Trust of New Zealand

Coastal Dune Ecosystem Reference Database

Moawhitu Wetland hydrological restoration: inundation scenarios, control structure and peak flow assessment

Author
James Blyth, Thomas Nation, Gareth Taylor
Year
2020
Journal / Source
Report by Taylor Collaborations Ltd for Department of Conservation
Summary
Department of Conservation (DOC) are considering the installation of an outlet control structure at Moawhitu Wetland on D’Urville Island. The structure would have the ability to adaptively control water levels over a large area, allowing for successive water level raises to promote hydrological and ecological restoration of the wetland, while also ensuring levels can be managed to maintain infrastructure. Following a site visit in February 2020, new survey points collected from the wetland and outlet channel were integrated with an existing digital elevation model (DEM) of the site. The updated DEM provides a detailed overview of ground elevations, which has been used to create water level inundation and depth contour maps for 3.0, 3.3, 3.6, 3.8 and 4.0 mRL.