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 5.7 Loddon system
Recent conditions
The mid-Loddon catchment had above-average rainfall in July 2019, but the middle and upper Loddon catchments were significantly drier than average during spring and for the first half of summer. Rainfall throughout the Loddon catchment was above average during late summer/autumn 2020, but that did not significantly affect storage levels. Seasonal determinations did not reach 100 percent in
the Loddon or Goulburn systems during 2019–20, but carryover, used of allocated water and environmental water transferred into the Loddon system from entitlements in the Goulburn system ensured that enough water was available to deliver all required environmental flows.
Rainfall in the Bet Bet Creek catchment caused spills at Laanecoorie Reservoir and Loddon Weir during July and August 2019, which provided a series of natural freshes and minor overbank flows in the Loddon River below Loddon Weir during early winter. Following the winter spills, flow in the Loddon system returned to the usual regulated conditions for the remainder of the year. Flow in the Loddon River above Loddon Weir, Serpentine Creek and Pyramid Creek exceeded the recommended environmental flow rates at various times during summer/autumn, due to consumptive water deliveries.
The planned environmental watering regime for reach 4 of the Loddon River under dry and average scenarios was entirely achieved in 2019–20. Following the winter high flow, the priority for the year was to continue year-round low flow in the Loddon River and provide summer-autumn freshes to protect water quality and refuge habitat in the Loddon River and Serpentine Creek. Carryover and water transferred
into the system made it possible to deliver a spring fresh, combining water from the Loddon River and Pyramid Creek during November 2019.
Monitoring stations continuously monitor temperature and oxygen in reach 4 of the Loddon River. Low oxygen and high water temperatures have occurred in the Loddon River under low flow conditions in previous years, but environmental flows and relatively cool conditions throughout the second half of summer/autumn prevented poor water quality during 2019–20. Environmental water will continue to be used in future, to reduce the risk of dangerously low levels of oxygen.
Scope of environmental watering
Table 5.7.1 describes the potential environmental watering actions in 2020–21, their functional watering objectives (that is, the intended physical or biological effect of the watering action) and the longer-term environmental objectives they support. Each environmental objective relies on one or more potential environmental watering actions and their associated physical or biological functions.
                  286 | Victorian Environmental Water Holder | Seasonal Watering Plan 2020–21

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