Notes

Priority actions – Lake Corangamite Catchment

The Lake Corangamite Catchment is located in the region’s north-west and includes the Woady Yaloak, Stony Rises and Lismore Landscape Zones. It is dominated by Lake Corangamite and other Ramsar listed lakes and wetlands, as well as the Victorian Volcanic Plain bioregion surrounding it, highlighted by extinct volcanoes such as Mount Elephant and Mount Leura. Agriculture is the dominant land use with cropping, followed by grazing, the most common land use practices. The main NRM groups in the catchment are the Woady Yaloak Catchment Group, Corangamite Lakes Landcare Network and the recently formed Stony Rises Land Management Network. Public land managers include Parks Victoria and to a lesser extent Colac Otway Shire. A number of specialist environmental and agricultural industry networks, e.g. Ballarat Environment Network and Southern Farming Systems, also address NRM issues in the catchment. Local municipalities include the Corangamite, Colac Otway and Golden Plains shires.

Natural values

The catchment has a number of creeks and streams that terminate at Lake Corangamite, which is the largest permanent inland lake in Australia. The Woady Yaloak River (the catchment’s largest waterway) and Pirron Yallock Creek flow into Lake Corangamite. Lake Colac is also a dominant lake in the catchment.

The upper parts of the catchment are largely dominated by agricultural land, with internationally significant wetlands and small remnants of native grassland and grassy woodland still remaining. Main agricultural practices include grazing, cropping and dairy.

To the south of the catchment, large areas of volcanic rock, formed from the most recent volcanic activity, are largely dominated by woodland interspersed with spring-fed freshwater wetlands, and have helped shaped the characteristic Stony Rises landscape.

Many of these small wetlands are seasonal herbaceous wetlands (freshwater) of the temperate lowland plains, and are listed as under the Commonwealth Environment Protection and Biodiversity Conservation Act, 1999. Within the Stony Rises landscape zone, Lake Colongulac, Lake Beeac and Horseshoe Lake are included under the Western District Lakes Ramsar site.

Potential impacts of climate change

A warmer and drier climate, combined with an increase in groundwater demand may potentially lead to changes to environmental flows into Lake Corangamite, the drying of lakes and wetlands and changes to land use practices.

Increased impacts and spread of drought tolerant invasive weed species, such as Tall Wheatgrass (Thinopyrum ponticum), will have impacts on already stressed ecosystems such as wetlands and fragmented areas of remnant vegetation and especially the last remaining areas of native grassland on the volcanic plains.

Blackberry (Rubus fruticosus aggregate), a dominant weed species to the south of the catchment may reduce its spread through the catchment, while Gorse (Ulex europaeus), a dominant weed species to the north, may increase its range southwards under climate change.

The fire regimes of the more heavily vegetated areas of the southern areas of the catchment may also change under a warmer and drier climate, with more frequent and intense events.

Climate change may impact a number of species in this catchment.

Examples of flora include the Spiny Peppercress (Lepidum aschersonii), Enfield Grevillea (Grevillea bedggoodiana) and Salt-lake Tussock-grass (Poa sallacustris). Examples of fauna species include the Striped Legless Lizard (Delma impar), Corangamite Water Skink (Eulamprus tympanum marnieae) and Brolga (Grus rubicunda).

Carbon sequestration opportunities

Carbon sequestration opportunities include revegetation through shelterbelts to the north of the catchment and riparian protection and wildlife corridors to the south. Opportunities for soil carbon may exist but more research is required to determine the best methods and locations. Opportunities for blue carbon sequestration within the many lakes and wetlands in this catchment may exist but require further research.

For more information click here http://www.swclimatechange.com.au/cb_pages/regional_planning.php

Natural asset	Vulnerability rating*	Climate change threat (direct &/or indirect)	Guiding adaptation responses	Stakeholders
Waterways – Pirron Yallock Creek, Kuruc-a-Ruc Creek, Little Woady Creek, Woady Yaloak River, Naringhil Creek	Very High	Higher temperatures and longer periods without rainfall will lead to less environmental flows and reduced areas of refugia for aquatic species. More intense rainfall events may lead to more areas being susceptible to bank erosion.	Prioritise areas within reaches for targeted revegetation to improve shading and habitat as well as alleviate impacts of potential bank erosion. Protect riparian vegetation through fencing. Revegetate priority areas and provide instream habitat. Investigate options for removing artificial fish barriers e.g. weirs). Investigate feasibility of relocating isolated fish populations (Yarra Pygmy Perch). Collaboratively review and optimise water management to increase waterway resilience.	CCMA, NRM groups, PV, Water Authorities, VEWH, Private landholders
Waterways – Gnarkeet Chain of Ponds, Mundy Gully	High
Native Vegetation – Riparian Forests or Woodlands	Very High	A hotter and drier climate may cause existing vegetation communities to change in their composition and structure, with some species being replaced by others. Fire regimes will be modified, most likely with more frequent and intense events. Vegetation communities may be vulnerable to environmental weeds. Some vegetation communities will be more vulnerable than others to the direct impacts of climate change e.g. Riparian Woodland.	Management could focus on maximising the resilience of communities and maintaining ecosystem function. In many cases this will mean managing native vegetation as we do today. Improving the current condition is likely to be important for the long-term viability of a community, with those in better condition more resilient to change in the short term, and more adaptable in the long term, due to their greater genetic, floristic and structural diversity.	NRM groups, PV, Trust, VicRoads, LGAs, CCMA, CFA, Private landholders
Native Vegetation – Plains Grassland/ Chenopod Shrublands	Very High - High
ative Vegetation – Lower Slopes/ Hills Woodland	High
Native Vegetation – Dry Forests and Plains Woodland/Forests	Moderate
Wetlands – Banogill Network, Lake Milangil, Kooaweera Lakes, Lake Struan, Stony ford-Bungador Wetlands and Lake Ondit	Very High	Wetlands that are highly vulnerable to a climate that is hotter and drier will reduce in both extent and quality. A reduction in rainfall and runoff could cause some temporary wetlands to dry up permanently. A reduction in water inflow may also cause an increase in the salinity of some wetlands, and changes in the types of vegetation communities that they can support. Wetlands that are reliant on groundwater/spring fed may also be impacted.	Management should focus on maximising the resilience of communities and maintaining ecosystem function. In many cases this will mean managing wetlands as we do today. Improving the current condition is likely to be important for the long-term viability of a wetland, with those in better condition more resilient to change in the short term, and more adaptable in the long term, due to their greater genetic, floristic and structural diversity. Research potential recycled water and stormwater sources from Colac (both quality and quantity), for Lake Colac. Develop a climate adaptation plan for Lake Colac and Lake Corangamite. Research ‘blue carbon’ opportunities of the catchment’s wetlands. Research potential groundwater sources (both quality and quantity) for selected wetlands. Research flora and fauna requirements of the littoral zone of major lakes in light of predicted changes caused by climate change. Explore feasibility of developing a ‘Western District Adaptation Pathways Plan.’	PV, NRM groups, CCMA, Private landholders
Wetlands – Lake Kariah, Lake Beeac, Horseshoe Lake, Eurack Swamp and Lake Weering	High
Wetlands – Lake Logan, Deep Lake, Lake Tooliorook, Lake Gnarpurt, Lake Corangamite, Lake Terangpom, Lake Rosine, Cundare Pool, Lake Martin, Lake Bullen Merri, Lake Colongulac, Lake Koreentnung, Lake Weeranganuk, Lake Coragulac, Lake Colac and Lough Calvert	Moderate
Wetlands – Widderin Swamps and Dereel Lagoon	Low
Agricultural Land	Low – Moderate	Climate change will have a direct impact on soil health and the ability of soil to support specific uses. Prolonged periods of higher temperatures and reduced moisture may lead to more areas being more susceptible to wind erosion. More intense rainfall events may also lead to areas of sheet, rill and gully erosion. Reduced vegetation cover due to climate change will also exacerbate these impacts. An increase in dryness and lack of moisture will also impact organic carbon in soil. Agricultural productivity may increase or decrease under a changing climate, depending on where it is located e.g. from grazing to cropping.	Addressing the impacts on soil will need to be assessed, planned and implemented at a site level due to a) the level of impact (often site-specific) and b) the adaptation response of the land manager of that site. A changing climate may mean that a current agricultural enterprise may need to also change to make better use of the climatic conditions, as well as changes to the soil properties that are expected. Research opportunities for soil carbon sequestration within this catchment should also be a priority.	Ag groups, NRM groups, CCMA, private landholders
Native Flora	Very High	The rate of climate change is likely to overtake the ability of most flora species to adapt and as a result, changes to the distribution of flora species are expected to occur. Changes in life cycle events e.g. flowering times, are also expected to greatly impact flora populations. There is also potential for greater tree mortality under climate change due to drought and temperature increases.	Management should focus on maximising the resilience of communities and maintaining ecosystem function. In many cases this will mean managing flora populations as we do today. Improving the current condition is likely to be important for the long-term viability of a community, with those in better condition more resilient to change in the short term, and more adaptable in the long term, due to their greater genetic, floristic and structural diversity. Protection and promoting the regeneration of large old paddock trees should be seen as a landscape priority due to their genetic capacity to survive through a significant range of climatic conditions and therefore provide a future seed source.	NRM groups, LGAs, CCMA, PV, DELWP (regional)
Native Fauna	Very High	The rate of climate change is likely to overtake the ability of most species to adapt and as a result, changes to the distribution of fauna are expected to be a major response to climate change. More mobile species may find refuge from increasing temperatures by shifting to higher, cooler elevations or cooler, south-facing slopes. Species already restricted to high altitudes without the option of upslope migration are expected to become extinct unless they are able to adapt. Some species will be more vulnerable than others to extinction. Species may not be able to shift to areas with suitable climatic conditions where they are located in fragmented habitats, or because of their limited dispersal ability. Species with small, isolated or fragmented ranges, or those with low genetic variation and specific climatic requirements, will be more vulnerable and local extinctions are likely.	Protect and enhance existing natural populations. Maintain and improve diversity. Accept and accommodate unavoidable loss and facilitate transformation, when possible. Reduce impacts from other impacts of climate change (i.e. invasive species & changes to flooding and fire regimes). Allow and create space for species shifts and movement throughout the landscape. Increase connectivity (i.e. buffers, corridors, stepping stones) and areas of refugia. Monitor species, communities and ecological processes. Research potential translocation sites around Lake Colac for the Corangamite Water Skink from nearby vulnerable sites to climate change. Undertake an analysis of RAMSAR-listed criteria for the Western District Lakes against predicted climate change impacts and associated management responses.	NRM groups, LGAs, CCMA, PV, DELWP (regional)