Notes

Priority actions – Barwon River Catchment

The Barwon River Catchment encompasses the Bellarine Peninsula east of Geelong, the Barwon and Leigh River catchments and the landscape that immediately surrounds Lake Murdeduke. It is characterised by the Bellarine coastline, the inland slopes and plains of the Otway Ranges, the gorges extending along parts of the Leigh River and a large part of the region’s volcanic plains. The Landscapes Zones of Leigh, Upper Barwon, Mid Barwon, Murdeduke and Bellarine are in this large catchment. NRM groups include Leigh Catchment Group, Upper Barwon Landcare Network, Geelong Landcare Network and Bellarine Catchment Network. Public land managers include Parks Victoria, City of Greater Geelong, Barwon Coast Committee of Management, and Bellarine Bayside Committee of Management. A number of specialist environmental and agricultural industry groups e.g. Ballarat Environment Network and Southern Farming Systems also address NRM issues in the catchment. Local municipalities include Golden Plains, Surf Coast, Colac Otway shires and the cities of Greater Geelong and Ballarat and the Borough of Queenscliffe.

Natural values

The major river in this landscape zone is the lower Barwon River, which is the main source of fresh water to the lower Barwon wetlands and estuary. Sections of the river support good riparian environments that include red gum woodlands and a number of significant species. The estuarine reach of the Barwon River incorporates a system of wetlands and lakes listed as wetlands of international significance under the Ramsar Convention as part of the Port Phillip Bay (Western Shoreline) and Bellarine Peninsula Ramsar Site. Examples include Lake Connewarre, Reedy Lake and Hospital Swamps.

This zone is part of the Victorian Volcanic Plain bioregion, which covers 2.3 million hectares, extending across south-west Victoria. It also contains highly valuable grasslands, grassy woodlands and scattered wetlands. Lake Murdeduke is a wetland listed under the Western District Lakes Ramsar site.

This is a productive agricultural region and was one of the first areas settled for agriculture around Geelong. Main agricultural practices include grazing, cropping and forestry.

Potential impacts of climate change

The Barwon River has a number of current challenges that climate change could exacerbate including reduced environmental flows and an increase of sediment loads from feeding tributaries.

These environmental challenges and the spread of drought tolerant invasive weed species, such as Tall Wheatgrass (Thinopyrum ponticum), will impact on already stressed ecosystems such as wetlands, fragmented remnant vegetation and riparian habitats. A warmer and drier climate, combined with an increase in groundwater demand, will cause many of the catchment’s wetlands and swamps to dry.

The fire regimes of the more heavily vegetated areas of the upper catchments of both the Leigh and Barwon Rivers, will 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 Clover Glycine (Glycine latrobeana), Small Scurf-pea (Cullen parvum) and Bellarine Yellow-gum (Eucalyptus leucoxylon subsp. bellarinensis). Examples of fauna species include the Australian Grayling (Prototroctes maraena), Hooded Plover (Thinornis rubricollis rubricollis) and Growling Grass Frog (Litoria raniformis).

Sea level rise will impact the coastline areas of the Bellarine Peninsula. Land use practices may change to adapt to the drier and warmer climate, as well as the already reduced access to water such as the Barwon River and groundwater sources.

Carbon sequestration opportunities

Carbon sequestration opportunities include revegetation through shelterbelts, agroforestry, riparian protection and wildlife corridors. Opportunities for soil carbon may exist but more research is required to determine the best methods and locations. High opportunities for blue carbon sequestration exist in the Bellarine Landscape Zone with areas of Coastal Saltmarsh on both public and private land and seagrass communities in Swan Bay and coastal areas to the north of the peninsula.

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
Major Waterway – Barwon River	Moderate - Low	Higher temperatures and longer periods without rainfall will lead to less flow and reduced areas of refugia for aquatic species. More intense rainfall events may lead to more areas 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, e.g. Yarra Pygmy Perch. Collaboratively review and optimise water management to increase waterway resilience.	CCMA, NRM Groups, DELWP (ARI), Barwon Water, VEWH, Private landholders
Other Waterways – Mia Creek and Warrambine Creek	Very High
Other Waterways – Waurn Ponds Creek, Dewing Creek and Pennyroyal Creek	High
Other Waterways – Native Hut Creek, Boundary Creek and Yarrowee River	Moderate
Other Waterways – Leigh River	Moderate - Low
Barwon River Estuary	Moderate	A sea level rise of between 0.8-1.1 metres by 2100, hotter temperatures, a reduction in rainfall and an increase in extreme natural events e.g. flooding, are all expected to impact the ecology and dynamics of the Barwon River Estuary.	Investigate opportunities to upgrade infrastructure that becomes inundated with high estuary water levels, with ‘green infrastructure’. Work with public land managers to improve resilience of estuarine vegetation to climate change. Protect riparian vegetation through fencing Restore riparian zone using appropriate revegetation. Maintain EstuaryWatch group for Barwon River Estuary to help monitor changes associated with climate change.	PV, Barwon Coast CoM, CCMA, NRM Groups
Native Vegetation – Wet or Damp Forests	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 should 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, CCMA, PV, LGAs, VicRoads, Trust, private landholders
Native Vegetation – Dry Forests, Plains Woodland or Forests, Lowland Forests, Lowland Slopes or Hills Woodlands, Riparian Forests or Woodlands	Moderate
Native Vegetation – Heathy Woodland, Salt Tolerant/ Succulent Shrublands, Coastal Scrubs Grassland/ Woodlands	Low
Wetlands – Lake Gherang and Bingley Swamp	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/stormwater sources from Point Lonsdale (both quality and quantity), for Lake Victoria. Develop a climate adaptation plan for Lake Victoria and Lake Murdeduke. Research ‘blue carbon’ opportunities of the catchment’s wetlands. Research potential groundwater sources (both quality and quantity) for selected wetlands.	PV, CCMA, NRM groups, Private landholders
Wetlands – Lake Victoria and Lake Thurrumbong,	High
Wetlands – Lake Murdeduke	Moderate
Coastal Wetlands – Lake Connewarree/Reedy Lake/Hospital Swamp) and Salt Lagoon	Very High	Coastal wetlands are very vulnerable to climate change. Increased drought frequency and intensity, decreases in freshwater inputs, rising sea levels and increases in coastal storm surges may all impact these important ecosystems. These conditions may also change the character of coastal wetlands through a reduction in size, conversion to dryland or a shift from one wetland type to another e.g. brackish to saline. Under hotter and drier conditions and reduced inflows, acid sulphate soils in coastal wetlands will face an increased risk of exposure. The retention of coastal wetlands will require planning approaches which allow for the migration of wetland communities to avoid significant loss in both extent and character.	Management should focus on maximising the resilience of communities and maintaining ecosystem function. Improving the current condition is likely to be important for the long-term viability of flora and fauna communities. Assess the likely impacts of climate change on coastal wetland processes (i.e. tidal exchange, berm position and shoreline recession, entrance openings, water balance, geomorphology, water quality and biodiversity). Monitor sea level rise and associated impacts. Plan areas for marginal terrestrial vegetation e.g. Coastal Saltmarsh, migration due to sea level rise. Prioritise blue carbon habitats and investigate blue carbon opportunities. Investigate opportunities to upgrade infrastructure that becomes inundated with high sea water levels, with ‘green infrastructure’. Develop an ‘Adaptation Plan for the Lower Barwon Wetlands’ including adjacent habitats. Establish the baseline condition and extent of all EVCs the Lower Barwon Wetlands to monitor impacts of sea level rise.	PV, NRM groups, CCMA, Private landholders
Coastal Wetlands – Swan Bay	Moderate			PV, NRM groups, CCMA, Private landholders
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.	NRM groups, LGAs, CCMA, PV, DELWP (regional)