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 3.5 Werribee system
Table 3.5.1 Potential environmental watering actions and objectives for the Werribee system
Potential environmental watering action
Pyrites Creek (reach 6)
Spring fresh (one to four freshes of 40 ML/day for two days during September to October)
Spring/summer high flow (one to three high flows
of 130 ML/day for two days during September to December)
Winter/spring/summer low flow (two ML/day [or natural] during June to December)
Functional watering objectives
• Drown terrestrial plant species that encroach into the waterway
• Increase the growth and recruitment of streamside and in-stream vegetation
• Scour silt, biofilms and algae from substrates to maintain the quality and quantity of food and habitat for waterbugs
• Wet depressions adjacent to the stream that frogs can use for breeding
• Drown terrestrial plant species that encroach into the waterway
• Increase the growth and recruitment of streamside and in-stream vegetation
• Transport carbon to drive aquatic food webs
• Scour silt, biofilms and algae from substrates to maintain the quality and quantity of food and habitat for waterbugs
• Wet depressions adjacent to the stream that frogs can use for breeding
• Maintain access to food and habitat for waterbugs, native fish and frogs • Increase the growth and recruitment of in-stream vegetation
Environmental objectives
Lower Werribee River (reaches 8, 9 and estuary)
Summer/autumn fresh (one to five freshes of 80 ML/ day for two days during November to May)
Winter/spring fresh (one to two freshes of 350 ML/day for three days during June to October)
Summer/autumn low flow (six ML/day during December to May)
• Support the growth and recruitment of water-dependent streamside vegetation
• Flush silt and scour biofilms and algae from substrates on the stream bed and maintain pools and channel dimensions
• Maintain access to habitat and improve water quality for native fish, frogs and platypus
• Provide enough flow for native fish to move downstream past natural or artificial barriers
• Maintain the quality and quantity of food and habitat for waterbugs
• Support the growth and recruitment of water-dependent streamside vegetation
• Flush silt and scour biofilms and algae from substrates on the stream bed and maintain pools and channel dimensions
• Provide movement cues and enough flows for fish to move upstream past natural and artificial barriers
• Maintain water quality and quantity of food and habitat for waterbugs and platypus
• Wet depressions adjacent to the stream that frogs can use for breeding
• Maintain the growth and recruitment of in-stream vegetation
• Support the growth and recruitment of water-dependent streamside vegetation
• Maintain water quality and food in pool habitats for native fish
• Maintain access to habitat for native fish, frogs, platypus and waterbugs
• Maintain flow through pool habitats to allow mixing or suppression/dilution of saline groundwater intrusion
112 | Victorian Environmental Water Holder | Seasonal Watering Plan 2020–21



























































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