Sea

The purpose of this Statement is to communicate how, for the purposes of environmental impact assessment, the Environmental Protection Authority (EPA)

• considers the object and principles of the Environmental Protection Act 1986 (the Act)
• provide the aims of EIA
• uses environmental factors and objectives to guide EIA
• considers significance throughout the EIA process
• takes a holistic view of the environment and a proposal potential impact on the environment
• considers cumulative effects when assessing a proposal potential impact on the environment.
• provide detail on the mitigation hierarchy

In the current version (Version 5.0), the Statement has been updated to reflect the revised Greenhouse Gas Emissions factor objective.

The purpose of this technical guidance is to:

• assist proponents to design fit-for-purpose modelling and monitoring programs to spatially define, assess and manage potential impacts of their proposal on marine environmental quality, and
• ensure proposals that have the potential to significantly affect marine environmental quality are described and assessed in a sound and consistent manner that demonstrates how the EPA’s objective for the Factor ‘marine environmental quality’ will be met.

The approaches outlined in this Guidance are not new. They have been applied to all significant and relevant proposals subject to formal environmental impact assessment for over a decade. This Guidance sets out the approach that has been refined and consolidated over this period in a single coherent document.

This document sets out the context for the guidance, describes the structure of the environmental quality management framework and how it is to be applied through environmental impact assessment to maintain a high level of quality in Western Australia’s marine waters. WA marine waters extend from the outer boundary of the State’s Coastal Waters through estuaries and inland to the limit of tidal influence where salinity is influenced by seawater, including marinas and canals that are contiguous with the marine environment. Although tailored to marine waters, the general approach is applicable to other estuaries and inland waters, but there are likely to be a different set of pressures and issues to be considered.

The EPA’s objective for the Factor Benthic Communities and Habitats is “to protect benthic communities and habitats so that biological diversity and ecological integrity are maintained”. The purpose of this Guidance is to explain how impacts on benthic communities and habitats (BCH) are considered during Environmental Impact Assessment (EIA) and to set out the type and form of the information that should be presented to facilitate the assessment of impacts on BCH in Western Australia’s marine environment.

This Guidance supersedes Environmental Assessment Guideline No.3 (EPA 2009), which mainly focused on protection of the primary producer component of BCH, and sets out:

• the EPA’s contemporary approach for considering activities which may directly or indirectly cause impact or serious damage to, or irreversible loss of, benthic communities and habitats;
• considerations for impact mitigation and how they should be applied;
• a framework for considering cumulative loss of benthic communities and habitats and the potential consequences for marine ecological integrity and biological diversity;
• the EPA’s expectations for information to be supplied by proponents for EIA; and
• the boundaries of a local assessment unit for the Port of Port Hedland that replaces Environmental Protection Bulletin 14 (EPA 2011) and is to be used when assessing benthic impacts and cumulative losses of benthic communities and habitats in the area.

The geographic scope of this Guidance includes all Coastal Waters of Western Australia to the high water mark of the intertidal zone associated with the continental mainland and offshore islands.

This Technical guidance describes the impact prediction and assessment framework that the EPA expects proponents and consultants to use so that predictions of the extent, severity and duration of impacts to benthic habitats associated with significant dredging activities are presented in a clear and consistent manner.

This is generic guidance that applies State-wide and as such, it does not differentiate between types of dredging proposals or regional environmental differences. Applying the framework across different projects provides a common approach to setting environmental outcomes and for monitoring impacts, which could improve understanding and prediction of dredging related environmental effects.

This version of the Technical guidance was published in October 2021. The framework remains largely unchanged, however the Guidance now incorporates the relevant scientific findings from the Western Australian Marine Science Institution’s Dredging Science Node. The information generated by the research has been collated and reviewed to identify and further refine the key findings, with input from relevant stakeholders. The bulk of the additional information is detailed technical advice most relevant to tropical north-west Western Australia and provided in three appendices. These appendices include suggested guideline values based on the tolerance of key biota to dredging pressures, the scientific rationale behind the values, advice relating to the pre-development baseline surveys required to support impact prediction and advice to assist proponents with post-approval monitoring and management programs.

It should be noted that while the framework outlined in this technical guidance is focussed on the Environmental Impact Assessment (EIA) of dredging-related activities, the approach can also be applied to the EIA of other types of development proposals to address uncertainty around impact predictions.

Factor guidelines and technical guidance: Sea

The biological communities that occur in Western Australia’s marine waters are largely shaped by the climatic regime, underlying geological structures, and the intensity of – and exposure to – wave and tidal energy.

The range of ecosystems, coupled with our relative isolation, has resulted in a very high diversity of marine life, much of which is found nowhere else in the world. The EPA considers the key ‘Sea’ factors of benthic communities and habitat, coastal processes, marine environmental quality and marine fauna in its assessment of significant proposals and schemes.