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Goulburn Broken Catchment Management Strategy

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Regional Catchment Strategy 2013-2019

1 Agricultural Floodplains

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The Agricultural Floodplains SES encompasses the Shepparton Irrigation Region (SIR) and northern parts of the Catchment to the River Murray. It includes the towns of Cobram, Nathalia Yarrawonga, Tatura, Kyabram, Tongala and Numurkah.

Yorta Yorta clans were the first people of the Agricultural Floodplains SES which has been significantly shaped since by natural events such as flooding and drought, and more recently by post-war soldier settlements in the irrigated lands, and the post-1950 agriculture technology boom. Landcare and the salinity pilot programs were formed to protect the landscape and more recently, water policy and reform has been important, particularly the current technological irrigation improvements including the G-MW Strategic Connections Project (formerly known as Northern Victorian Irrigation Renewal Project (NVIRP)) and improved on-farm systems.

Values, products, goods and services of this system

Agricultural production and processing industries are highly valued for the economic value they provide to this SES. River ecosystems and wetlands are highly valued for the ecological and economic services they provide. The Barmah and Lower Goulburn National Parks are valued for their biodiversity and recreational assets. The health of these areas are essential to Traditional Owners' cultural and spiritual connections to the land, evidenced by the large number of Aboriginal cultural heritage sites located in this area.

The resilience of the Agricultural Floodplains is about this system’s ability to stay in a state that provides these values in the face of change. This state underpins the future aspiration for the Agricultural Floodplains: an area

that is highly productive in ways that maintain and enhance its natural and cultural features.

Biodiversity

Since European settlement, this SES has been highly modified from its original state, which was open grassy woodlands, dominated by River Red Gum forests, with Grey Box, and Yellow Box among other dominant species over a sparse understory of wattles, peas and herbs. The Barmah and Lower Goulburn National Parks are the closest representations of the original riverine forests. There are few remaining examples of other types of vegetation communities, such as those dominated by Grey Box, Black Box, Murray Pine and Buloke.

The current condition of biodiversity in this SES is poor, with remaining native vegetation scarce and highly fragmented, mostly occurring as single scattered paddock trees and small remnant patches. Understory species are rare except in larger patches or through recent revegetation activities. Generally, there is one to three per cent native vegetation cover on private land and therefore, this SES is considered 'relictual' (generally defined as less than 10 per cent native vegetation cover).  Therefore, protecting the existing remnants and large old trees is critical in conserving biodiversity, while considering future potential for restoration.

Key terrestrial habitat for this SES are Box, Red Gum, Murray Pine and Buloke woodlands all of which are associated with the Broken, Boosey, Murray and Goulburn systems, and are critical to the long-term viability of the River Red Gum communities along the major waterways.

Threatened species and communities include Superb Parrot and Grassy Woodlands (all ecological vegetation classes on private land are threatened with extinction, and Box Gum Grassy Woodlands are Federally listed in the Environment Protection and Biodiverstiy Conservation Act as threatened).

The greatest threats to biodiversity in this area are the continuing incremental loss of scattered paddock trees, and the decline in quality and extent of remnants, particularly those associated with major waterways. Threats include clearing through land use changes, grazing, pest plant and animal invasion and loss of large old trees (natural death and direct removal) on private land and roadsides. The same threats exist on public land with additional threats from tourism and recreation use and timber and firewood removal.

Land

Agricultural production is the dominant land-use in this SES. It is supported by the provision of water harvesting, storage and delivery and drainage infrastructure, and soils suitable for a range of farm production enterprises; including dairy and horticulture. Dryland agricultural production in this SES includes cropping and grazing enterprises.

Erosion, organic matter decline, soil acidification, contamination, compaction, salinisation, sodicity, waterlogging and biodiversity decline are all threats in this SES related to agricultural land-uses. Pest plant and animal invasion also threatens land-use in this SES, including Paterson’s Curse, Fleabane, Foxes and Rabbits. New and emerging weed examples such as Chilean Needle Grass and African Love Grass are also considered significant threats to the Agricultural Floodplains.

Poor natural drainage is an inherent feature of the intensively irrigated floodplains, and from the 1950s to the 1980s salinisation emerged as a major issue across the area. Salinity continues to be the major threat in this SES with soil salinisation linked to the salinity of, and depth of shallow watertables. Watertable depth, combined with poor drainage, also contributes to soil waterlogging in the SIR. Significant land assets have been identified where the watertable depth are approaching zones that can negatively impact soil health and land assets.

Irrigated agriculture

The hydrological cycle in the SIR has undergone massive change since European settlement due to clearing of native vegetation and the introduction of irrigation. The result has been about nine per cent of land in the Agricultural Floodplains SES adversely affected by shallow, saline watertables. Deep lead aquifers are considered to be in good condition, although water yield was affected during the 1997-2009 drought.

The condition of agricultural land-use is heavily influenced by the efficient delivery and use of water on farms. Long term average historical water  losses were estimated about 800-900 gigalitres a year in the Goulburn Murray Irrigation District (up to 2004/05), which encompasses the SIR. Losses in any individual year will vary depending on customer deliveries in that year. For example, in a drought year with lower customer deliveries, losses will be less. These losses were in part attributed to ageing and inefficient irrigation infrastructure. The G-MW Strategic Connections Project was initiated to reduce these losses through modernisation of the public irrigation delivery system.

Efficient water use on farm helps to minimise salinity, water logging and nutrient impacts by reducing surface run off and seepage to the watertable. Australian and Victorian Government and individual investment made in significant infrastructure assets, supports land and soil assets deemed best matched to irrigated agricultural production. A predicted outcome of this modernisation program is more land under dryland production, but the impact of this change on land and soil health is unknown. While improved irrigation efficiency helps reduce adverse impacts of irrigation, other than in severe drought, accessions to the watertable will exceed deep drainage resulting in high watertables and salinity.

Water

The Agricultural Floodplains SES is mostly low lying floodplains, with some sandhills near the Murray and Goulburn Rivers. The river ecosystems are a dominant feature across the landscape.

Regulation, and the associated timing and volume of flow delivery in channels and across the floodplain is the greatest threat to waterways, which are typically highly modified from their original state. Most waterways are currently in poor condition. Priority waterway assets are:

Goulburn River: A Heritage River associated with wetlands of national significance supporting threatened species including Murray Cod, Silver Perch and Macquarie Perch. It contains many cultural heritage sites and provides water for agriculture, urban and recreational use.

Seven Creeks: Supports the threatened Trout Cod and Macquarie Perch.

Gobarup Creek: Associated with wetlands of national significance.

Broken River: Associated with wetlands of national significance and supports the threatened Murray Cod, Macquarie Perch and Silver Perch.

Broken Creek: Supports the threatened Murray Cod and is associated with wetlands of international significance.

Wetlands form a critical part of the river ecosystems of the Agricultural Floodplains. Current wetland condition is generally moderate to good. Wetlands on public land are in better condition than private land, where they are considered to be in generally a poor state. The biggest threats to this state are river regulation, inadequate drainage and landforming. Priority wetlands assets are:

Barmah Forest (Ramsar listed/The Living Murray (TLM) Icon Site): Along with the adjoining Millewa forest in NSW, it forms the largest River Red Gum forest in the world. It is one of Victoria’s largest waterbird breeding areas and protects 38 rare or threatened plant species.

Kanyapella Basin (Directory of Important Wetlands of Australia (DIWA) listed): Mixed River Red Gum forest and Black Box woodland which protects the nationally threatened River Swamp Wallaby Grass and provides flood retardation.

Muckatah Depression (DIWA listed): A long and narrow prior stream depression connecting larger wetlands. It protects a number of threatened plant species and provides important habitat for waterbirds including the threatened Brolga.

Gaynor Swamp (DIWA listed): A large Red Gum lignum swamp that supports tens of thousands of water birds.

Wanalta Wetland Complex (DIWA listed/Bioregional): Four hydrologically connected wetlands valued for their size, rarity, species diversity and waterbird habitat.

Reedy Swamp (DIWA listed): A significant breeding area for colonial nesting waterbirds including the threatened Royal Spoonbill. It provides important drought refuge.

Kinnairds Swamp (Regional): A Red Gum swamp that protects the largest known population of the nationally threatened Rigid Water Milfoil in Victoria. It provides important breeding habitat for waterbirds including the threatened Royal Spoonbill.

Black Swamp (Bioregional): A small Red Gum swamp that protects the nationally threatened River Swamp Wallaby Grass and Australasian Bittern.

Carlands Swamp (DIWA listed): a private wetland with the most eastern Victorian area of tangled lignum swamp.

Regulation, and the associated timing and volume of flow delivery in channels and across the floodplain is the greatest threat to waterways, which are typically highly modified from their original state. The health of rivers is also strongly influenced by the management and condition of upstream catchments and waterway systems.

People

The SIR creates agricultural products worth an estimated $1.38 billion (Monticello 2012). This highlights the dependency of the Agricultural Floodplain SES on agriculture and food manufacturing for employment, as well as the range of services that supports this production.  There are many threats to the agricultural capacity needed to support local processing in the future.

The area has a history of community leadership and involvement in NRM, particularly in relation to irrigation when faced with threats such as salinity. The Salinity Pilot Program Advisory Council broke new ground in the 1980s in its approach to engaging the community to manage the threat associated with rising watertables. Landcare networks and groups, the Goulburn Valley Environment Group (GVEG) and CMNs are active in this SES, playing a key role in production-focused and environmental advocacy and on-grounds works programs. However, volunteer burnout is considered a threat to the way people manage natural resources, as well as the ongoing group leadership and contribution to NRM.

Developing resilience of the Agricultural Floodplains SES

Table 8 details what is needed to develop resilience in the Agricultural Floodplains SES, building on needs best addressed at the whole-of-Catchment scale, which were listed in Chapter two.

Table 8.  Adapting to drivers of change in the Agricultural Floodplains SES*

Context

Management measure

Possible specific action (examples)

The greatest threat to ecological health of the abundant waterways and wetlands in the Agricultural Floodplains is management of upstream waterway systems, including regulation of flows. Timing and volume of flows are being adjusted as part of significant water policy reforms, which aim to balance delivery of water (within thresholds) for:

  • biodiversity habitat (within and downstream of the catchment, including wetlands outside of riparian areas)
  • irrigation and associated processing industries
  • domestic consumption.

Catchment partners, including community leaders, communicate Agricultural Floodplains SES priorities to Catchment and broader scale water policy bodies.

Over the last 20 years, significant investment in initiatives such as water treatment plants, water reuse, and dairy shed effluent management has helped reduce nutrients to the water quality strategy's target levels. The Catchment's water quality has improved, although isolated problems remain.

Strategic priority: Influence regional water policy

Influence water policy development and implementation to secure water for improving natural resource condition and social and economic wellbeing

Continued community, DSE, Goulburn Broken CMA, DPI and water authority partnerships to provide balanced and informed input into policy development

Create opportunities for community leaders to contribute to water policy

Involve industry body representatives in Farm Water Program design

Strategic priority: Deliver water to waterways and wetlands

Plan, deliver and monitor environmental water delivery to improve the condition of priority waterways and wetlands

Meet Ramsar obligations for Barmah National Park including provision of natural flooding patterns

Prioritise protection of waterway and wetlands within the modernised irrigation delivery system

Consider in the development of the 2013 Regional Waterways Strategy

The dry extreme of climate variability, which resulted in the 1997 to 2010 drought, meant that limited water was available to share. Resilience thresholds might have been crossed, with accelerated restructuring of dairying and horticultural enterprises (many individuals left the industries) and associated closures of major food processing factories. Past droughts continue to alter the identity and functioning of several townships.

Water, energy and labour efficiency programs through water policy reform are helping the Agricultural Floodplains retain its food production function, although there is likely to be a threshold around the minimum area of irrigated land needed for viable industry. Water savings are being shared between the environment, irrigators and other users.

Increased water efficiencies also help make soils and environmental features more resilient by reducing accessions to the watertable: watertable depth and salinity level thresholds are critical objectives for management. The recent wet end of the climate variability range, which resulted in repeated extreme rainfall events, is leading to rapid recharge of watertables.

Fire regime risks in public land such as Barmah are exacerbated when there are extended dry periods, which are part of climate variability, placing biodiversity habitat at risk.

Strategic priority: Use water efficiently on farms

Modernise water delivery on irrigated land to provide ecological and productivity benefits

Continue implementation of the Farm Water Program for ecological and agricultural production benefits

Strategic priority: Adapt to climate variability risks

Factor risks of climate variability and identify adaptation strategies in Goulburn Broken CMA plans

Develop addendum for Biodiversity Strategy

Develop public land fire management plans that consider loss of biodiversity

Goulburn Broken CMA input into a strategic approach to planned burning in Barmah that considers ecological values

Irrigated water delivery and management changes from modernisation drive the need for changes in drainage and shallow groundwater management.

Land-use change due to irrigation modernisation and the demand for increased farm production introduces threats to biodiversity, soils, wetlands, cultural heritage and groundwater, including off-site threats of water use. Farm production is constrained by several aspects of soil health related to salinity, such as soil sodicity.

Also, farms outside the irrigation infrastructure modernisation footprint are likely to become less viable and could undergo significant land-use change, providing a different suite of challenges.

Strategic priority: Capture opportunities from land development

Deliver farm planning to integrate ecological and agricultural productivity benefits

Whole farm or total property management planning

Promote land-use capability assessments and implementation, including use and management of water

Streamline new Irrigation Development Guidelines linked to whole farm planning and supported by planning schemes

Strategic priority: Manage risks to agricultural production

Deliver surface and sub-surface drainage works across a modernised irrigation delivery system, including adaptive shallow groundwater management

Make the case for a renewed investment in a drainage works program to support investment in irrigation infrastructure modernisation

Strategic priority: Establish sustainable agricultural practices

Create awareness and acceptance of sustainable management practices to improve land and soil condition

Research costs and benefits of new options for farm productions, such as energy production

Streamside native vegetation widths and connections to terrestrial remnant vegetation are important considerations in maintaining the viability of public land reserves and threatened species populations.

Strategic priority: Increase biodiversity as part of agricultural land-use

Create awareness and acceptance of land management practices to enhance and protect terrestrial and aquatic habitat

Research to understand more about the productive benefits associated with habitat protection and enhancement, such as vegetation corridors and the retention of large, old trees.

Identify environmental stewardship opportunities for land managers

Community-led projects like the Superb Parrot Project

Work with landholders to protect and improve biodiversity on farms and build understanding of its contribution to the landscape

Education campaigns to target high value assets

Extreme climate variability has resulted in extreme drought, bushfires and floods over the last decade, impacting on the people in this SES long after the event.

Strategic priority: Respond to and recover from climatic events

Plan and implement flood, fire and drought response and recovery

Delivery of support to affected communities

* Notes on the table:
The table (and descriptions on the previous page) will be part of background information for consultative planning and implementation over the next few years, which will include decisions on how to keep the SES from crossing undesirable thresholds.
Significant uncertainties in setting desirable SES thresholds and measuring progress elevate the need for close collaboration between SES stakeholders when setting priorities.  Some key threshold parameters to be considered when making decisions are listed in the table. Appendix five includes a more complete list across all SESs, with some quantitative targets.