5.3 Evaluation 5.1 Summary of monitoring and evaluation questions for water quality parameters during the water actions from irrigation canal escapes. Detailed findings are presented in Appendix A. CEWO Water Planning and delivery Monitoring and Evaluation questions and outcomes Flow component type and target/planned magnitude, duration, timing and/or inundation extent (CEWO 2016) Expected outcomes of watering action (From Use Minute 10038 and/or CEWO Acquittal report) LTIM Question Observed outcomes What information was the evaluation based on? Were appropriate flows provided to achieve the expected outcome? CEW delivered from irrigation escapes To provide hypoxic water refuge for fish and other aquatic biota (WUM 10054-03, 10054-04 10054-05). What did Commonwealth environmental contribute to temperature regimes? NA Gaps in the logger data make this difficult to assess, but this was not an expected outcome of the Local refuges were achieved, with greater extent around the Wakool and Edward Escapes where larger volume releases were possible. Greater impact would be achieved by starting releases earlier in future blackwater events, where possible. What did Commonwealth environmental water contribute to dissolved oxygen concentrations? Some dilution effects (increased DO) downstream of Edward and Wakool Escapes during escape flows Spot measurements and field observations What did Commonwealth environmental water contribute to nutrient concentrations? Some small dilution effects observed. Water samples What did Commonwealth environmental water contribute to modification of the type and amount of dissolved organic matter through reconnection with previously dry or disconnected channel habitat? NA- this was not a target of flows What did Commonwealth environmental water contribute to reducing the impact of blackwater in the system? Creation of local refuges with improved water quality in the immediate vicinity of the escapes. Small downstream improvements at some sites. samples, spot measurements, observations
Late autumn/winter watering actions To create recession flows at the end of the unregulated flows. To reinstate part of the continuous flows that would have occurred prior to river regulation during winter-spring. To improve links with other parts of the river system (WUM 10054-07, 10054-08) What did Commonwealth environmental water contribute to temperature regimes? NA- this was not a target of these flows CEW was delivered to all zones, making water quality impacts of the flow difficult to assess. However, the small delivery of CEW to zone 2 supported what would be an otherwise extremely low flow in this zone and is likely to have supported DO concentrations in this zone. What did Commonwealth environmental water contribute to dissolved oxygen concentrations? CEW may have assisted with maintenance of DO in Zone 2 where flow would have otherwise been extremely low. Water samples, spot measurements, observations What did Commonwealth environmental water contribute to nutrient concentrations? NA- this was not a target of these flows What did Commonwealth environmental water contribute to modification of the type and amount of dissolved organic matter through reconnection with previously dry or disconnected channel habitat? NA- this was not a target of these flows What did Commonwealth environmental water contribute to reducing the impact of blackwater in the system? CEW supported the maintenance of flow following blackwater and water quality parameters remained in acceptable ranges over this period. Water samples, spot measurements, observations trial
7.3 Evaluation Table 7.2 Summary of effects of Commonwealth environmental watering on aquatic and riverbank vegetation. N/A = Not applicable to this watering action. Detailed findings are presented in Appendix C. CEWO Water Planning and delivery Monitoring and Evaluation questions and outcomes Flow component type and target/planned magnitude, duration, timing and inundation extent (CEWO 2016) Expected outcomes of watering action LTIM Question Observed outcomes What information was the evaluation based on? Were appropriate flows provided to achieve the expected outcome? CEW delivered from irrigations escapes To provide hypoxic water refuge for fish and other aquatic biota (WUM 10054-04 What has Commonwealth environmental water contributed to the recovery (species richness, cover and recruitment) of riverbank and aquatic vegetation in Yallakool Creek and the mid and upper Wakool River and how do those responses vary over time? N/A Riverbank and aquatic vegetation was not monitored at sites in association with the irrigation escapes watering actions How do vegetation responses to Commonwealth environmental water delivery vary among hydrological zones? N/A What did CEW delivered as base flows and freshes contribute to the percent cover of riverbank and aquatic vegetation? N/A What did CEW delivered as base flows and freshes contribute to the taxonomic richness of riverbank and aquatic vegetation taxa? N/A Recession flows and late autumn/winter watering action in Yallakool Creek To reinstate part of the continuous flows during To improve links with other parts of the river system (WUM 10054-07, What has Commonwealth environmental water contributed to the recovery (species richness, cover and recruitment) of riverbank and aquatic vegetation in Yallakool Creek and the mid and upper Wakool River and how do those responses vary over time? No effect detectable Vegetation surveys The flood event in 2016 decreased the richness and cover of submerged and amphibious taxa and increased the richness and cover of terrestrial taxa. There was no recovery of submerged and amphibious taxa during recession flows or autumn/winter watering action How do vegetation responses to Commonwealth environmental water delivery vary among hydrological zones? No difference detectable What did CEW delivered as base flows and freshes contribute to the percent cover of riverbank and aquatic vegetation? No effect detectable What did CEW delivered as base flows and freshes contribute to the taxonomic richness of riverbank and aquatic vegetation taxa? No effect detectable
8.3 Evaluation 8.2 Summary of fish movement responses to Commonwealth environmental watering. N/A = Not applicable to this watering action. Detailed findings are presented in Appendix D. CEWO Water Planning and delivery Monitoring and Evaluation questions and outcomes Flow component type and target/planned magnitude, duration, timing and/or inundation extent Expected outcomes of watering action (From Water Use Minute 10038 and/or CEWO Acquittal report) LTIM Question Observed outcomes What information was the evaluation based on? Were appropriate provided to achieve the expected outcome? To provide hypoxic water refuge for fish and other aquatic biota (WUM 10054-03, 10054-04 10054-05). To reinstate part of the continuous flows during winter-spring. To improve links with other parts of the river system (WUM 10054-07, 10054-08) Were periodic species (golden and silver perch) present in the target reaches during Commonwealth environmental water delivery? Only a proportion of the tagged sample of fish survived the hypoxic blackwater event Location of tagged individuals within the system based on either current movements or the last valid detection No. Timing of flow delivery was generally too late to protect the majority of individuals. Did periodic species remain within the target reaches during Commonwealth environmental water delivery? Yes – see above Location of tagged individuals within the system based on either current movements or the last valid detection Did Commonwealth environmental water stimulate periodic fish species to exhibit movement consistent with reproductive behaviour? NA NA Does Commonwealth environmental water enable periodic species to disperse from and return to refuge habitat? NA NA Does Commonwealth environmental water protect periodic species from adverse water quality? Possibly, although note that the timing of e-flow delivery from irrigation escapes was too late to ensure survival of many fish Location of tagged individuals within the system based on either current movements or the last valid detection
Table 9.2 Summary of fish spawning responses to Commonwealth environmental watering. N/A = Not applicable to this watering action. Detailed findings are presented in Appendix D. Fish spawning and reproduction CEWO Water planning and delivery Monitoring and Evaluation questions and outcomes Flow component type and target/planned magnitude, duration, timing and/or inundation extent Expected outcomes of watering action (From Water Use Minutes and/or CEWO Acquittal report LTIM Question Observed outcomes What information was the evaluation based on? Were appropriate flows provided to achieve the expected outcome? CEW delivered from irrigation escapes To provide refuge from hypoxic water for fish and other aquatic biota Could not be assessed Recession and late autumn/winter watering action in Yallakool Creek To influence different changes in rises that may contribute to silver perch spawning. To provide a number of peaks at a time when water temperature is suitable for silver perch spawning. To determine if level rises timed with periods of 23°C water temperature and no moon (dark night sky conditions) has any influence on silver perch spawning response. What did commonwealth environmental contribute to increased spawning activity of equilibrium species (e.g. Murray cod, river blackfish? NA (The watering actions occurred outside the time when equilibrium species usually N/A N/A What did commonwealth environmental water contribute to ‘periodic’ flow spawning species (e.g. golden and silver perch, bony herring) Environmental flow delivery occurred outside the monitoring period, and therefore not be assessed. No evidence of golden perch or silver perch spawning was found during the sampling period No eggs or larvae of golden perch or silver perch were detected with targeted fortnightly sampling, which involved using drift nets across the four study zones, from Sept to Dec 2016 High unregulated floods in 2016-17 did not trigger spawning in golden or silver perch in Yallakool Creek or the Wakool River. Environmental flows occurred outside the monitoring period, and therefore could not be assessed. What did commonwealth environmental contribute to the spawning of ‘opportunistic species’ (e.g. small bodied fish) Most opportunistic species spawned on the recession of the coinciding with Commonwealth Monitoring abundance of larval fish using light traps Watering actions on the flood recession did not specifically target spawning of opportunistic fish, but occurred at a time when spawning of these taxa usually occurs and
10.3 Evaluation 10.2 Summary of fish recruitment responses to Commonwealth environmental watering. N/A = Not applicable to this watering action. Detailed findings are presented in Appendix D. CEWO Water Planning and delivery Monitoring and Evaluation questions and outcomes Flow component type and target/planned magnitude, duration, timing and/or inundation extent Expected outcomes of watering action (From Use Minute 10038 and/or CEWO Acquittal report) LTIM Question Observed outcomes What information was the evaluation based on? Were appropriate flows provided to achieve the expected outcome? CEW delivered from irrigations escapes To provide hypoxic water refuge for fish and other aquatic biota Could not be assessed Recession flows and late autumn/winter watering action in Yallakool Creek Autumn pulse and recession also to assist with movement of juvenile native fish Could not be assessed