BeckerFraserPhotos April 2011 photograph 781

Images, UC QuakeStudies

Photograph captioned by BeckerFraserPhotos, "Footpath subsidence beside the Twin Towers monument, Kilmore Street".

BeckerFraserPhotos April 2011 photograph 043

Images, UC QuakeStudies

The riverbank walkway along New Brighton Road, flooded at high tide due to ground subsidence.

BeckerFraserPhotos April 2011 photograph 042

Images, UC QuakeStudies

The riverbank walkway along New Brighton Road, flooded at high tide due to ground subsidence.

BeckerFraserPhotos April 2011 photograph 041

Images, UC QuakeStudies

A dock by the riverbank walkway alongside New Brighton Road which has been closed off to the public. The area has flooded at high tide due to ground subsidence".

BeckerFraserPhotos April 2011 photograph 022

Images, UC QuakeStudies

Sandbags placed along the river bank to prevent flooding onto the road. The earthquake caused the ground in this area to subside , making it susceptible to flooding.

Floodplain restoration principles for the Avon Ōtākaro Red Zone. Case stud…

Research papers, University of Canterbury Library

The Canterbury region of New Zealand experienced a sequence of strong earthquakes during 2010-2011. Responses included government acquisition of many thousands of residential properties in the city of Christchurch in areas with severe earthquake effects. A large and contiguous tract of this ‘red zoned’ land lies in close proximity to the Ōtākaro / Avon River and is known as the Avon-Ōtākaro Red Zone (AORZ). The focus of this study was to provide an overview of the floodplain characteristics of the AORZ and review of international experience in ecological restoration of similar river margin and floodplain ecosystems to extract restoration principles and associated learnings. Compared to pre-earthquake ground levels, the dominant trend in the AORZ is subsidence, together with lateral movement especially in the vicinity of waterway. An important consequence of land subsidence in the lower Ōtākaro / Avon River is greater exposure to flooding and the effects of sea level rise. Scenario modelling for sea level rise indicates that much of the AORZ is exposed to inundation within a 100 year planning horizon based on a 1 m sea level rise. As with decisions on built infrastructure, investments in nature-based ‘green infrastructure’ also require a sound business case including attention to risks posed by climate change. Future-proofing of the expected benefits of ecological restoration must therefore be secured by design. Understanding and managing the hydrology and floodplain dynamics are vital to the future of the AORZ. However, these characteristics are shared by other floodplain and river restoration projects worldwide. Identifying successful approaches provides a useful a source of useful information for floodplain planning in the AORZ. This report presents results from a comparative case study of three international examples to identify relevant principles for large-scale floodplain management at coastal lowland sites.