Table 4 Site-specific ecological targets and associated flow indicators for Great Cumbung Swamp Without-development and baseline event Site-Specific flow indicators frequencies Event Proportion of years the Proportion of years Frequency-proportion of years event Ecological Target event occurred under the event occurred required to achieve target Flow modelled under modelled Duration required Timing conditions baseline conditions (days) Low uncertainty (%) High uncertainty (%) (ML/d) (%) (%) Provide a flow regime which ensures the current extent of native vegetation of the riparian, 25 floodplain and wetland communities is sustained (minimum 700 60 50 69 44 in a healthy, dynamic and resilient condition continuous (June to duration) November) Provide a flow regime which supports recruitment opportunities for a range of native aquatic species (e.g. fish, frogs, turtles and invertebrates) 35 (total Provide a flow regime which supports key duration ecosystem functions, particularly those related to 1,500 45 40 56 35 above flow (June to connectivity between the river and the floodplain threshold)a November) Provide a flow regime which supports the habitat requirements of waterbirds and is conducive to 30 successful breeding of colonial nesting waterbirds (minimum 2,700 20 20 26 18 continuous (June to duration) November) a Duration is expressed both as a total and minimum duration, allowing multiple smaller flow events that met the minimum duration criteria to comprise a successful event. Minimum durations are therefore a subset of total duration and should not be read independently. MDBA analysis showed that if a minimum duration is not specified and individual events must meet the total duration criteria, this resulted in a significantly reduced proportion of years. Note: Multiplication of the flow rate by the duration and frequency (proportion of years event required) does not translate into the additional volume of water the site needs to be environmentally sustainable. This is because part of the required flow is already provided under baseline conditions. Additional environmental water required is the amount over and above the baseline flows.
Table 4 Site-specific ecological targets and associated flow indicators for Great Cumbung Swamp Ecological Target Site-Specific flow indicators Without-development and baseline event frequencies Event Frequency-proportion of years event required to achieve target Proportion of years the event occurred under modelled conditions (%) Proportion of years the event occurred under modelled baseline conditions (%) Flow required (ML/d) Duration (days) Timing Low uncertainty (%) High uncertainty (%) Provide a flow regime which ensures the current extent of native vegetation of the riparian, floodplain and wetland communities is sustained in a healthy, dynamic and resilient condition Provide a flow regime which supports recruitment opportunities for a range of native aquatic species (e.g. fish, frogs, turtles and invertebrates) Provide a flow regime which supports key ecosystem functions, particularly those related to connectivity between the river and the floodplain Provide a flow regime which supports the habitat requirements of waterbirds and is conducive to successful breeding of colonial nesting waterbirds 700 25 (minimum continuous duration) (June to November) 60 50 69 44 1,500 35 (total duration above flow threshold)a (June to November) 45 40 56 35 2,700 30 (minimum continuous duration) (June to November) 20 20 26 18 a Duration is expressed both as a total and minimum duration, allowing multiple smaller flow events that met the minimum duration criteria to comprise a successful event. Minimum durations are therefore a subset of total duration and should not be read independently. MDBA analysis showed that if a minimum duration is not specified and individual events must meet the total duration criteria, this resulted in a significantly reduced proportion of years. Note: Multiplication of the flow rate by the duration and frequency (proportion of years event required) does not translate into the additional volume of water the site needs to be environmentally sustainable. This is because part of the required flow is already provided under baseline conditions. Additional environmental water required is the amount over and above the baseline flows.
EWR-Great-Cumbung-Swamp.docx