Key challenges and opportunities
Australia has a highly variable climate, and rainfall is especially variable. This makes it vital that we understand as much as we can about our climate so we can work out how we manage our water supplies. The frequency and duration of wet and dry events determines how much water we have available.
NSW is already experiencing trends of higher average temperatures and reduced cool season rainfall. There are indications from climate models that drought conditions may become more frequent and severe, and last longer.
Higher demand from a growing population, alongside reductions in supply, will increase water scarcity, putting further pressure on all users, including the environment (Productivity Commission, National Water Reform Issues Paper, May 2020, p.2).
It is vital that we collectively improve our understanding of these risks to better manage water supply and ensure that our operational, planning and future development decisions take future likely water reliability and security into account.
Net Zero Plan - taking action on climate change
The NSW Government is committed to achieving net zero emissions by 2050 and to making NSW more resilient to a changing climate.
The Net Zero Plan Stage 1: 2020-2030 is the foundation for NSW’s action on climate change. The Plan aims to grow the economy, create jobs and enhance the prosperity and quality of life of the people of NSW while allowing the state to deliver a 35% cut in emissions by 2030 compared to 2005 levels.
The NSW and Australian governments are jointly investing more than $2 billion over 10 years to help the state fast-track climate action through energy and emissions reduction initiatives delivered under the Plan. This includes actions targeting energy efficiency, electric vehicles, hydrogen, primary industries, coal innovation, organic waste and carbon financing.
The implementation of the Net Zero Plan, together with the NSW Electricity Strategy, will result in more than $11.6 billion of new investment for NSW, including $7 billion in regional NSW, and support the creation of almost 2400 new jobs.
The Climate Change Fund is supporting programs and projects to improve NSW’s resilience to natural hazards and climate risks. This includes investment in world-leading climate research, support for councils, communities and agencies to better prepare for and respond to heatwaves, storms, floods, droughts and bushfires,
the Five Million Trees initiative and coastal risk management programs.
The Government is also delivering local scale climate change adaptation programs to help communities understand the impacts of climate change in their areas and prepare for and adapt to these impacts, including taking action to protect ecosystems and vital natural assets and resources. Find further information on these and other climate change actions.
Source: Office of the Chief Scientist & Engineer, April 2020, Independent review of the climate risk method for the NSW Regional Water Strategies Program
Our 130 years of recorded information provides a good indication of average conditions, and shows a small number of extreme droughts and floods. We are now using paleoclimate records to better understand the likelihood of these extreme events. By analysing sources such as tree rings, cave stalactites and stalagmites, river sediments, soil patterns, and ice cores, we can identify the past duration and frequency of these events, for periods up to 500 years. We have combined this with our recorded information and our understanding of the key climate drivers, using statistical techniques, to generate 10,000 years of plausible past climate sequences. This information provides a better source of information to identify and assess the potential risks and outcomes of water management decisions under our current climate.
We have then combined this new 10,000 years of ‘current’ climate information with the climate change information provided by the NSW and ACT Government’s NARCliM project (see box on next page) to investigate the impacts of future human induced climate change on our rainfall and evaporation across the state. The method was developed by Department of Planning, Industry and Environment - Water with advice from the Universities of Newcastle and Adelaide. This new data and modelling approach has been independently reviewed by the Office of the NSW Chief Scientist and Engineer and a panel of independent experts and found to be best practice and a major advance on existing approaches.
We are considering worst-case scenarios
The NSW and ACT Regional Climate Modelling (NARCliM) Project is a research partnership between the NSW and ACT governments and the Climate Change Research Centre at the University of NSW.
NARCliM climate change datasets include a range of different future climate scenarios. We have used the most conservative result from NARCliM in our modelling for the regional water strategies - the scenario that represents the greatest reduction in average monthly rainfall. While the results of the other scenarios in the current version of NARCliM are arguably equally appropriate and probable, we intend to ‘stress test’ the water system and understand the worst-case climate scenarios for strategic water planning. This will test the resilience of options proposed in the regional and metropolitan water strategies, particularly options that aim to secure water for critical human needs.
Source: Department of Planning, Industry and Environment—Water 2020, hydrological modelling
Note: The shaded area represents a 95th percentile confidence interval which means a high degree of confidence that values will fall within the shaded range based on the climate projection scenario.
Source: Department of Planning, Industry and Environment - Water 2020, hydrological modelling
Action 4.4 Better integrate land use planning and water management
The Government will better integrate strategic land use planning with water management frameworks and outcomes. We will take steps to:
|a.||establish processes to support communication and early engagement to better inform land use, agriculture and industry investment decisions based on a clear understanding of water availability and constraints, and water allocation risk over the immediate and longer term|| |
|b.||develop new planning policies, if required, to integrate land use and water cycle management decisions|
|c.||identify opportunities for the planning system to support water resource health and resilience in a changing climate; for example, through strategic recognition of critical groundwater resources in coastal areas and mitigate impacts from urban development|
|d.||improve access to information about water availability to support development|
|e.||examine opportunities for information on high value water-dependent ecosystems and cultural values to be considered in land use planning decisions.|
Case Study: Wianamatta South Creek Delivery Strategy
Wianamatta South Creek is a major tributary of the Hawkesbury-Nepean River in the western Sydney Basin that runs 80 km from Narellan to Windsor. A large part (80%) of the 63,000 ha catchment falls within the Western Parkland City urbanised area, covering 6,000 km2 and eight local government areas. The catchment is experiencing both rapid and incremental scales of change from rural to predominantly urban land use, including development of the Western Sydney Aerotropolis precinct.
Wianamatta South Creek and its catchment has a critical role to play in realising the vision for the Western Parkland City to create cool, green and attractive urban communities by retaining water in the landscape, integrating water cycle planning in the design of new neighbourhoods and supporting the health and management of waterways.
This vision has been captured in several strategic land use planning frameworks, including the Greater Sydney Region Plan and Western City District Plan, with links to the proposed Design and Place State Environmental Planning Policy.
Premier’s priorities for open space and greening are also key requirements, with about two million trees to be planted in the area.
New integrated land use and water cycle management approaches and major policy reforms are required to achieve the economic, amenity and environmental objectives of the Western Parkland City. Reflecting this, the South Creek Catchment Sector Review identified changes to land use controls and major water- related infrastructure investment decisions:
- Stage 1 of the South Creek Sector Review identified significant economic value in taking an integrated approach to land use, water cycle management and investment in advanced recycling water infrastructure in developing the Western Parkland City. This value was estimated at around $6.6 billion (NPV), compared to a business-as-usual approach
- Stage 2 of the South Creek Sector Review included a strategic economic analysis of stormwater and waterways governance, which found that a catchment-wide approach to planning and delivery of stormwater infrastructure and waterways management could deliver a significant economic benefit (which is being investigated further).
To achieve these changes, a Delivery Strategy is being developed to provide an adaptive and tactical 40-year framework and the tools needed for integrated land use and water cycle management for the Wianamatta South Creek catchment. The strategy focuses initially on actions aligned with planning for the Western Sydney Aerotropolis.
The Delivery Strategy will cover green and blue infrastructure, land use outcomes, catchment health and flooding, connected spaces and the interfaces and relationships with future development, utilities and transport. It will also address current and future land controls and ownership, and is being developed collaboratively with Aboriginal communities, landholders, local government, Sydney Water and other stakeholders. A key first step is Sydney Water’s planning for the Upper South Creek Advanced water recycling scheme.