Draft Manning River Catchment and Estuary and Catchment Management Program 2021-2031 - Main document

5.1.2

Results

A summary of high risk subcatchments is provided in Table 2. Targeted on-ground works in these subcatchments will have the best chance of improving the health of the Manning estuary by mitigating threats using a holistic approach. The highest risk of impacts from nutrient and sediment inputs, acidic runoff from acid sulfate soil, and pathogen inputs from stock on ecological and community values of the Manning estuary comes from the Lansdowne River catchment.

Risk Assessment

High risk subcatchments

Estuary Health Risk

Lansdowne River (88, 223), Cedar Party Creek (95) (Figure 22)

Stock pathogen risk on drinking water quality

Dingo Creek (86), Manning River (99, 105), Barrington River (117), Gloucester River (98, 122)

Stock pathogen risk on Aquaculture

Oxley Island (203), Mamboo Island (204), Jones Island (205), Lansdowne River (88,223) Cattai Creek (93)

Erosion risk impacting riparian vegetation

Manning River (105,110), Upper Manning River (92, 96), Myall Creek (76), Barnard River (82)

Acidic runoff

Lansdowne River (88, 223), Cattai Creek (93)

Table 2: Subcatchments posing the highest risk to ecological and community values NB: The numbers in brackets (Table 2) relate to numeric identifier codes used for drainage units within each subcatchment there are 88 numbered drainage units in the catchment. There is considerable variation between within individual subcatchments, meaning the results cannot necessarily be applied to an entire subcatchment but should be used as a guide to further field investigations. Figure 22 shows the Estuary Health Risk Map. Subcatchments in red pose the highest risk of sediment and nutrient loading into the estuary.

Draft Manning River Catchment and Estuary and Catchment Management Program 2021-2031 - Main document

Articles inside

Figure 39 MidCoast Council Organisational Structure

Appendix 6: MCC land-use strategies aligned to the CM SEPP objectives

Implementation Streams

Appendix 2: The Public Participation Spectrum

13. Bibliography

12. Proposed amendments to the CM SEPP

11.3 The Manning River ECMP Research Program

11.1 MERI for the Manning River, Estuary and Catchment

7. Management Actions

6.15 Systems thinking: the interaction between issues

10. Coastal Zone Emergency Sub-Plan

6.13 Sewerage and Septic System Pathogens

Figure 33: The Manning River floodplain, 20 March 2021

Figure 32: Cattle on the riverbank is a common sight

Table 4: Key impacts associated with water pollution from diffuse-source runoff

Figure 25: Estuary with negative impacts vs well-managed estuary

Figure 27: Cattai Wetlands

Figure 26: Conceptual diagram of the Greenhouse Effect

Figure 24: The relationship between activities, stressors and ecological impacts

Figure 22: Risk ratings for sediment and nutrient loading in drainage units

Table 2: Subcatchments posing the highest risk to ecological and community values

Figure 21: Stock intensity in the catchment

Figure 18: Manning River TN and TP readings from 2015-18

Figure 17: The sampling location for water quality data

Figure 9: The Integrated Planning and Reporting Framework

Figure 15: National Parks make up18.5% of the Manning catchment

Figure 14: Program Logic Model

Figure 12: Values our community ascribed to each subcatchment

Figure 11: The consultation program

Figure 16: Water quality monitoring sites in the estuary

Figure 10: Option for the Manning River ECMP Governance Structure

Figure 7: The five stages of a Coastal Management Program