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A scenario-based approach to evaluating potential environmental impacts following a tidal barrage installation


Kidd, IM and Fischer, AM and Chai, S and Davis, JA, A scenario-based approach to evaluating potential environmental impacts following a tidal barrage installation, Ocean & Coastal Management, 116 pp. 9-19. ISSN 0964-5691 (2015) [Refereed Article]

Copyright Statement

2015 Elsevier Ltd. All rights reserved.

DOI: doi:10.1016/j.ocecoaman.2015.06.016


Total exclusion barrages have a high impact on estuarine systems as they are permanent barriers to tidal flow. The environmental impacts of five putative barrages in various locations within the Tamar River estuary in northern Tasmania, Australia were assessed by considering likely hydrological, morphological and ecological outcomes. We found that all hypothetical barrages would produce downstream silt accretion, some to the point where a major port would become unusable without ongoing dredging. The closer a barrage was located to the mouth of the estuary, the greater the loss of tidal prism, the lower the effect of flushing by floodwaters, and the greater the loss of estuarine biodiversity. Eradication of invasive rice grass (Spartina anglica) in the mid estuary is potentially a positive outcome, whilst constant headpond surface heights could cause bank erosion and subsidence. Loss of tidal wetlands would contravene the international treaties protecting the migratory waterbirds which use these habitats. Installation of a barrage at the uppermost location appears to represent the best trade-off between adverse impacts and increased recreational and visual amenity. Unfortunately, barrage installation at any site within the estuary fails to address the major anthropogenic stressors of reduced riverine inflows and tidal flushing. A wider sustainability analysis is needed in which the costs of meeting environmental, social and economic objectives are considered.

Item Details

Item Type:Refereed Article
Keywords:Total Exclusive Barrage, Remnant Estuary, Tidal Prism, Bathymetry, Migratory Species, Morphology
Research Division:Environmental Sciences
Research Group:Environmental management
Research Field:Environmental management
Objective Division:Environmental Management
Objective Group:Terrestrial systems and management
Objective Field:Assessment and management of terrestrial ecosystems
UTAS Author:Kidd, IM (Mr Ian Kidd)
UTAS Author:Fischer, AM (Dr Andy Fischer)
UTAS Author:Chai, S (Professor Shuhong Chai)
ID Code:102081
Year Published:2015
Web of Science® Times Cited:11
Deposited By:NC Maritime Engineering and Hydrodynamics
Deposited On:2015-07-27
Last Modified:2017-12-06

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