<< BACK TO CONTENTS Gunbower Forest Natural flooding in the Murray system led to water entering parts of Gunbower Forest that had been dry for more than four years. Rainfall as much as 200 per cent above average in the Goulburn, Kiewa and Ovens river catchments in July 2016, led to overbank flooding of many River Murray floodplains including Gunbower Forest. North Central CMA Gunbower Forest Project Manager Anna Parker said these flows presented a rare opportunity to use additional environmental flows to improve the forest’s longterm health. “Without river modification, the natural floodwaters would have been higher for longer, and modelling shows water would have been in the forest from early June,” she said. “Even so, natural floods are always better for the forest and we need to take advantage of them when they happen. The high river triggered natural cues which led fish to swim onto the floodplain to feed and breed. “Nature gave us a flood. We used water for the environment to open up the forest and connect the River Murray to Gunbower Creek. This put an indelible stamp on the health of the forest,” Anna said. “The water that came naturally from north-east Victoria was full of nutrients, having travelled across floodplains to get to Gunbower. Washing this water through our system and back out into the Murray provided plants, fish and other animals with a feast, helping them to boost their numbers.” River red gum responded with a flush of new growth and are now in better condition than before. Black box communities on the higher floodplains were inundated for several weeks, helping the many aquatic understorey species including common nardoo to flourish. Fish surveys provided a welcome surprise: significant numbers of threatened Murray–Darling rainbowfish were found in the forest wetlands. These fish haven’t been found in the forest in years. The return of these rainbowfish indicates environmental water is making a big difference to the rehabilitation of the forest wetlands, especially the permanent wetlands where aquatic plants are thriving. Meanwhile, year-round flows in Gunbower Creek were again used to support native fish through their life cycles. Winter flows helped maintain habitat and food for juvenile fish in the creek: usually, the creek is drawn down to a series of deep pools at the end of the irrigation season. Environmental flows provided cues for fish to spawn, supported adult fish to nest and gave juvenile fish the best chance to survive the colder winter months. Fish populations, especially of Murray cod, are thriving in the better conditions. Fish surveys show that the fish are not only breeding, but that more juvenile fish are surviving and becoming a more-resilient population. Site Gunbower Forest Gunbower Creek1 Volume delivered in 2016–17 (ML) VEWH MDBA CEWH Total 196 2,894 - - - 23,563 1 Deliveries to Gunbower Creek included some reuse of return flows. A turtle at Gunbower Creek, by North Central CMA 3,090 23,563 Reflections – Environmental watering in Victoria 2016–17 | 78
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