Page 55 - VEWH Seasonal Watering Plan 2020-21
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Leading up to the 2020-21 Seasonal Watering Plan, focus on the lower Latrobe wetlands has included:
• on Country discussions with GLaWAC and Gunaikurnai Elders and Community to examine cultural values and uses
• discussions regarding the importance of maintaining the wetlands as a freshwater system to support culturally significant species, including totem species
• the importance of the lower Latrobe wetlands to the Gunaikurnai traditionally, and today
• concerns regarding water quality, increasing salinity
• concerns regarding pest species including carp.
GLaWAC are sharing with the West Gippsland CMA plant and animal species of cultural significance in and around the waterways of the Latrobe Valley, and the importance of specific watering decisions to support them.
Watering requirements to support cultural values and uses include:
• timing of environmental watering planned in partnership with GLaWAC to support a seasonal flow regime and wet and dry periods that embody Healthy Country
• maintaining freshwater supply to Latrobe estuary, Dowd Morass, Sale Common and Heart Morass and associated freshwater habitats. The lower Latrobe wetlands are an important resource for the Gunaikurnai
• providing connectivity between reaches and onto floodplains to support dependent flora and fauna with cultural values and uses of significance to the Gunaikurnai
• maintaining water quality to support health of native flora and fauna with cultural values and uses of significance to the Gunaikurnai.
Social, recreational and economic values and uses
In planning the potential watering actions in Table 2.2.3, the West Gippsland CMA considered how environmental flows could support values and uses including:
• water-based recreation (such as canoeing and fishing)
• riverside recreation and amenity (such as camping, birdwatching, duck hunting and amenity for access tracks)
• socio-economic benefits (such as commercial fishing).
Recent conditions
Climatic conditions in the lower Latrobe wetlands’ catchment varied throughout 2019–20. Total rainfall
was below average, but there were still some significant rain events that increased river levels throughout winter
and spring 2019, particularly from the Latrobe River catchment, and they caused minor overbank flooding
in late spring 2019 and again in late autumn 2020. The VEWH’s entitlement for the lower Latrobe wetlands is not limited in volume, and regulator gates may be opened opportunistically based on water height in the Latrobe River at Swing Bridge.
Heart Morass, Dowd Morass and Sale Common were allowed to draw down in 2018–19 to allow the die-off of aquatic vegetation, promote nutrient cycling and allow terrestrial grasses and sedges to establish. Overbank
flows in late winter and early spring 2019 partly refilled the wetlands. Environmental water was subsequently delivered as required (and when salinity in the Latrobe River estuary was not too high) to maintain water quality and habitat for aquatic and terrestrial animals, and to support the growth and flowering of semi-aquatic vegetation. Complete and near-complete fills were achieved at Dowd Morass and Heart Morass respectively in 2019–20, and a partial fill was achieved at Sale Common. A flushing flow was delivered to Heart Morass in spring 2019 to export salts and sulfates. Water levels at all wetlands were drawn down partially
over summer to expose mudflats, which created feeding opportunities for wading birds and oxygenated soils to promote seed germination. High rainfall in late April and May 2020 caused minor flooding, allowing deliveries of freshwater to the lower Latrobe wetlands again in autumn.
Some water was retained in Dowd Morass and Sale Common to maintain habitat for Australasian bittern and other significant waterbirds that were observed at these sites during summer. Maintaining this habitat will likely be a priority throughout 2020–21.
Scope of environmental watering
Table 2.2.3 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 objective(s) they support. Each environmental objective relies on one or more potential environmental watering actions and their associated physical or biological functions.
2.2. Latrobe system
  Victorian Environmental Water Holder | Seasonal Watering Plan 2020–21 | 53

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