Compiled Reference Document - MCU25/0020 (As Published)

ADG Consulting Pty Ltd

 

4 Water quality objectives
4.1 Receiving environment

It is proposed to discharge extracted groundwater directly over the revetment wall into the Noosa River
canal system adjacent to the site. The exact location of the receiving waters/environment will be
confirmed on commencement of dewatering.

The receiving environment in this location identifies as a tidally flushed, moderately disturbed, canal,
harbour or marina environment connected to the marine Noosa River. The following section establishes
water quality objectives (WQOs) to ensure that the environmental values of the receiving waters are
protected and maintained.

4.2 Development of water quality objectives

WQOs have been developed to support and protect the designated environmental values (EVs) for the
receiving environment. The WQOs are based on a moderately disturbed level of protection for tidal
canals, constructed estuaries, marinas and boat harbours. The WQOs have been developed with
reference to the following guideline documents:

— Australian and New Zealand Guidelines for Fresh and Marine Water Quality 2018. (ANZG 2018) The
selected trigger values apply to moderately disturbed systems to provide a 95% level of species
protection for marine waters.

— Environmental Protection (Water & Wetland Biodiversity) Policy 2019. Queensland Government.
— Noosa River environmental values and water quality objectives. 2022. DES.
- Queensland Water Quality Guidelines, Version 3, September 2009. 2013. DEHP.

The Australian and New Zealand Guidelines for Fresh and Marine Water Quality by the Australian and
New Zealand Environment and Conservation Council and Agriculture and Resource Management Council
of Australia and New Zealand (ANZECC/ARMCANZ, 2000), has undergone review, with the publication of
the 2018 version. The revised Australian and New Zealand Guidelines for Fresh and Marine Water Quality
2018 is a joint initiative between the Australian and New Zealand Governments and Australian state and
territory governments (ANZG, 2018) and supersedes the ANZECC/ARMCANZ 2000 publication. Where
ANZECC/ARMCANZ (2000) is referenced, the relevant sections are still relevant and consistent with the
updated ANZG 2018 publication, as referenced in the ANZG 2018 publication.

The Queensland Water Quality Guidelines 2009 (DEHP, 2013) was made pursuant to the provisions of the
Environmental Protection (Water) Policy 1999, now the Environmental Protection (Water & Wetland
Biodiversity) Policy 2019 (the EPP(Water)), which is a subordinate legislation under the Environmental
Protection Act 1994 and was developed as the State response to the ANZECC/ARMCANZ (2000)
Guidelines. The EPP(Water) provides a framework for:

-— Identifying environmental values for Queensland waters, and deciding the water quality objectives
to protect or enhance those environmental values.

— Including the identified environmental values and water quality objectives under Schedule 1 of the
EPP (Water).

WQOs are long term goals for surface water quality management. They are indicators established for
receiving waters to support and protect the designated Environmental Values (EVs) for those waters. DES
(2022) describes that for slightly to moderately disturbed waters, the guideline values should be
compared with the median of values at a test site, whilst ANZG (2018) stresses that the aquatic ecosystem
guideline values are triggers to further action, are inherently conservative, and that the response to non-
compliance should match the magnitude and impacts (if any) of the exceedance.

Regardless of the WQOs adopted in this DMP, the General Environmental Duty set out in the EP Act is
paramount, which requires that “a person must not carry out an activity that causes or is likely to cause

 

ADG1786.25 Dewatering Management Plan_Rev1_07.10.25 Page 7