Gosford City Council Historical Water Quality Review & Analysis

FUTURE DIRECTIONS FOR WATER QUALITY / ENVIRONMENTAL HEALTH MONITORING 4-23
4.6.1 Recommendations for a Gosford Environmental Health Indicator
Based on the Coastal CRC EHMP template, an appropriate Environmental Health Indicator for the
Gosford water would incorporate the results of both biotic and abiotic assessments. As a minimum, it
is recommended that the following be integrated into an Environmental Health Indicator:
• Water Quality (as defined by Compound Water Quality Index or associated scorecards);
• Seagrass depth assessment (as and when the opportunity arises to incorporate seagrass
monitoring into routine Council environmental assessment programs); and
• Benthic macroinvertebrate assessment (based on the initial Biodiversity Study by University of
Newcastle [Dr Bill Gladstone], and assuming that repeatable assessments could be carried out at
least annually as part of Council’s future environmental monitoring programs).
In the first instance, however, it is likely that the only measure of Environmental Health will be the
Compound Water Quality Index, as described in Section 3.1.3. The limitation of assessing only
abiotic parameters, needs to be recognised though.
With regard to the Compound Water Quality Index, or more specifically the Water Quality
Scorecard, objectives can be set for different locations based on an understanding of the estuarine
processes throughout the Gosford waterways. Recommended targets for future water quality scores
are shown in Table 4.3.
Table 4.3
Recommended Water Quality Scores for different sections of the
Gosford Waterways
Location
Water Quality
Score
Additional Objectives
Lower Brisbane Water (e.g. Booker Bay) 10/10
Upper Brisbane Water (e.g. Koolewong) 9/10
Brisbane Water tributaries 8/10 Ammonia < 0/01 mg/L
NO x < 0.02 mg/L
Coastal Lagoons 8/10 Chlorophyll < 2 µg/L
Recommendations regarding seagrasses and benthic macroinvertebrates, along with guidelines for
amalgamating results into one ‘Environmental Health Index’ would be determined following baseline
monitoring of the biological components.
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