INTEGRATED WATER QUALITY MONITORING PROGRAM - BURGESS CREEK (Referred from Planning & Environment Committee Meeting dated 11 July 2023 - Item 5.8) · Report

GENERAL COMMITTEE MEETING                                                                 17 JULY 2023



Review of Water Quality Objectives
Council has been in communication with DES regarding the review and update of the Noosa River
Environmental Values and Water Quality Objectives (WQOs), as defined under the Environmental
Protection (Wetland & Biodiversity) Policy 2019. DES reviews the WQOs approximately every 10
years, with the most recent draft objectives made public in June 2022.

The updated objectives were developed in consultation with and using historical data from NRM
groups, Unitywater and other relevant stakeholders. Key changes include the introduction of high
and low flow targets and separate objectives for Burgess Creek. Under the previous guidelines,
Burgess Creek did not have its own WQOs, instead Wallum/tannin stained streams guidelines were
used. Under Unitywater's EA, they must meet set release limits for parameters such as total nitrogen
and total phosphorus, however, they are not obligated under this legislation to meet the water quality
objectives for the Burgess Creek Catchment. The changes have resulted in a substantial increase
in the guidelines used for Burgess Creek for oxidised nitrogen, and a small increase in total nitrogen
concentrations under high flow conditions. Under these objectives compliance is low. Council has
requested that Unitywater engage with DES to determine whether the discrepancy between the EA
limits and the WQOs is appropriate.

Monitoring reports prepared by Noosa’s NRM groups and citizen scientists for the Noosa Shire,
Noosa River, Kin Kin Creek and coastal creeks (Castaways, Marcus and Peregian creeks) have
provided sub catchment report card ratings by comparing them with the WQOs. Several locations in
these reports received an 'F', resulting from exceedances of the WQOs for both dissolved oxygen
and turbidity. At the most recent water quality workshop as part of the integrated water quality
monitoring program held 15 March 2023, participants discussed concerns that the some of the
WQOs were not relevant to certain sites.

Council has provided the citizen scientist reports to DES for analysis and met to discuss the updated
objectives and development of local WQOs. Noosa & District Landcare raised issues with the
appropriateness of the WQOs for three coastal ephemeral creeks (Castaways, Marcus and Peregian
creeks) for electrical conductivity, and for dissolved oxygen for several locations in Kin Kin and
Wahpunga creeks. DES is now considering minor proposed legislative amendments to the WQOs
for these 3 coastal creeks, expected late in 2023.

University of Sunshine Coast Research Project - Coastal Monitoring
One of the key findings of Council’s Coastal Hazards Adaptation Plan was that coastal monitoring
represented a critical component of any adaptive management program. Council is undertaking
engineering design incorporating natural stabilisation to manage erosion occurring on the Eastern
Beaches, including development of priority ratings for coastal creeks to facilitate active monitoring
and maintenance. Burgess Creek’s mouth has been identified by community members as an erosion
hotspot.

Council is collaborating with UniSC on a one-year research project to investigate Burgess Creek’s
channel migration by monitoring water quality, 2D and 3D morphological changes in the creek and
development of an empirical model to predict triggers forcing changes in the creek’s water quality
and morphology. The project is also monitoring water flow and depth.

The creek’s planform change, channel depth and beach/dune volumetric changes will be surveyed
using drone photogrammetry and Real-time Kinematic Global Navigation Satellite System (GNSS)
profiles on a ~monthly and/or event-driven basis (e.g. before/after significant swell or rainfall events).
Nearshore hydrodynamics (waves and currents) will be modelled using a calibrated Simulating
Waves Nearshore (SWAN) model. An XBeach model will be used to model beach/dune volumetric
changes and tested using observed data.

The creek’s water surface level is being monitored using a pressure sensor at the mouth (west side
of the bridge) based on significant events (e.g. during significant swell >3m significant wave height