Murrumbidgee environmental water use by entitlement (updated to 30/06/14) (Murrumbidgee 2014-15 Water use Acquittal Report) Use Volume (ML) Wetland Zone Start – End Date Event Name NSW AEW NSW EWA NSW LTIM GS SUPP NSW SUPP Total Volume delivered (ML) Nap Nap Swamp to Waugorah Ck 630 18565 Uara Creek to Yanga 21757 LSAL North Caira Floodways 7849 LSAL 7489 Kia Lake 10000 10000 Telephone Bank Swamp 4930 4930 Nimmie-Caira Southern Bell Frog Wetlands 2000 3113 LSAL 5113 Nimmie 343 343 Western Lakes Paika Lake 1459 1535 8498 11492 Redbank Mid North Redbank, return flows 3136 13204 56340 Upper North Redbank 6648 20000 26648 Juanbung 4667 5688 National Park 6280 19070 70000 4512 LSAL 99862 Yanga 7885 5893 Yanco Yanco Creek 245 2462 1372 5732 Mid-Murrumbidgee Yarradda Lagoon 1150 1150 Sandy Creek 130 250 380 MIA wetlands 2472 2472 Coonancoocabil wetlands 720 720 Old Man Creek 840 840 Gras Innes and Oak Creek 1278 1,278 Commonwealth environmental contributed to eight watering actions within the Murrumbidgee Valley in 2014-15. These actions were anticipated to achieve the following expected outcomes: protect, maintain, and in some cases improve the condition and extent of floodplain, riparian and wetland native vegetation maintain and improve the diversity and condition of native aquatic including fish, waterbirds, frogs, turtles and invertebrates through maintaining CEW CEW
Nutrients, carbon and productivity Outcomes summary Concentrations of nutrients, carbon and chlorophyll-a as well as of Gross Primary Production (GPP) and Ecosystem Respiration (ER) are key covariates that account for variability in primary producers (e.g. photosynthetic algae and plants) and dependent higher-trophic indicator organisms such as invertebrates and fish (). Flow plays a critical role in supporting ecosystem metabolic processes both in rivers and wetlands. Samples of nutrients, carbon and chlorophyll-a were collected fortnightly between October 2014 and January 2015 at six sites across the Narrandera and Carrathool zones of the Murrumbidgee River. While in wetlands, concentrations of nutrients, Dissolved Organic Carbon (DOC) and chlorophyll-a were sampled every 2 months across ten sites between September 2014 and March 2015. Relevant objectives relating to environmental water delivery to the Lowbidgee Floodplain (Action 6) include the provision of habitat to support the survival and maintain condition of native fish, waterbirds, and other aquatic vertebrates. In there were no environmental watering actions specifically targeting in-channel or wetland nutrients, carbon and chlorophyll-a and rates of GPP and ER. However, environmental water deliveries to the Lowbidgee floodplain contributed to patterns of in-channel hydrological variability, providing baseline information to help explain the potential role of environmental flows in maintaining ecological beneficial concentrations of nutrients, carbon and chlorophyll-a and rates of GPP or ER. Key findings There were two notable peaks in nutrient levels which coincided with increasing water levels in the Murrumbidgee River. This was explained by increasing water levels during bulk water deliveries which resulted in the inundation of dry sediments and the release of nutrients.
than 24 average native CPUE was 6.2. In sites with water depth lower than 0.91m average CPUE was 2.3 and those between 0.91m and 0.26m had average CPUE of 5.9. Figure 59 Classification and Regression Tree of native fish CPUE abundance Exotic fish The proportion of the wetland inundated had a significant effect on the abundance of exotic species, with exotic fish species more abundant in wetlands that were only partially inundated (less than 0.8) (Figure 60). Of these wetlands with higher exotic fish CPUE, deeper wetlands had higher CPUE than did wetlands less than 0.24m, broadly reflecting the response of all fish species to wetland inundation. Figure 60 Classification and Regression Tree of exotic fish CPUE abundance Frogs and tadpoles Overall, 2,212 adult frogs (seen and heard) and 1,100 tadpoles of six species were recorded between September 2014 and May 2015 across 10 LTIM monitoring sites, with two sites remaining dry throughout 2014-15. Adult barking marsh frogs (Limnodynastes fletcheri), spotted marsh frogs (Limnodynastes tasmaniensis), plains froglets (Crinia parinsignifera) were recorded in all three zones. Peron’s tree frogs (Litoria peronii), inland banjo frogs (Limnodynastes interioris) were less widespread, while the vulnerable southern bell frog (Litoria raniformis) had the most restricted distribution, only occurring across the four Nimmie-Caira sites. Commonwealth environmental watering targeted known habitats of the southern bell frog (Litoria raniformis) in the Nimmie-Caira zone (Action 6). Calling and tadpoles of southern bell frogs and other frog species were recorded at all four LTIM monitoring wetlands in the Nimmie-Caira, indicating that these flows were successful