Are our waterways under threat?

    Modelling for Wollondilly was carried out against the predicted population forecast to identify key threats for our waterways. The key threat is from stormwater. For example Nitrogen being discharged into waterways from stormwater is forecast to increase approximately 1000 tonnes per year (total 1200t) by year 2036. 

    This is a major strain on the health of our waterways and we need to adopt principles that will minimise the velocity and pollutant load of stormwater in our waterways to preserve them long term.

    Can a zero impact on waterways be achieved from new development sites?

    Yes. 

    The main stormwater issue we need to address from developments is runoff from impervious surfaces which increases stormwater volume and pollutant loads in our natural waterways. The 2 main types of impervious surfaces are rooves and roads. 

    We have provided a practical example for roads and rooves to get to zero impact on waterways in the Strategy. 

    Rooves can be dealt with using appropriately sized rainwater tanks plumbed into laundry, toilets and hot water. This will have the added benefit of decreasing the potable (drinking) water demand by 72%. Roads can be dealt with by replacing curb and gutter and stormwater pipes which will irrigate street trees and vegetated swales. This is will enable greener neighbourhoods.

    These are excellent examples of stormwater harvesting and reuse which conserve water and will be a step towards buffering the impacts of drought. These will also minimise the need for Council infrastructure (like gross pollutant traps and bioswales) that Council needs to maintain, therefore reducing the cost and resource demand on Council – and the community.    

    Why go for an integrated water approach that includes wastewater?

    Certain wastewater treatment methods compete with stormwater treatment methods so we need to consider them both in a holistic management system.

    Wastewater that goes to treatment plants is 99% water. This is a sustainable, consistent and reliable source of significant water volumes.

    What if we began to think of this treated wastewater as a useful resource to be put to work?  Treated wastewater has to go somewhere. It could be directed to our rivers and oceans, or we could make the most of it as a resource – for example using it for agricultural irrigation. For the long term protection of our waterways and to improve the resilience of the community and environment it’s important that we consider including wastewater in our policy and strategy for managing water. 

    What are some options for treated wastewater?

    • Treat and discharge into waterways – This is a commonly used method. It does not utilise water as a resource and can impact the health of waterways.
    • Treat and utilise water for agriculture and industry – Utilises water as a resource and helps protect waterways. 
    • Treat and reuse for irrigation and pipe to households for use in toilet and laundry (purple pipe) – This method minimises discharge to natural environments and saves on potable (drinking water) use, however, can compete with stormwater management measures like rainwater tanks for stormwater harvesting. 
    • Raw Water Augmentation - The Purification of drinking water from wastewater to supplement the drinking water supply. 

    What is Raw Water Augmentation exactly, and why should we consider it?

    Raw Water Augmentation is where wastewater is treated and purified to potable (drinking) standard and used to supplement the drinking water supply. 

    Wastewater that goes to treatment plants is 99% water. This is a sustainable, consistent and reliable source of significant water volumes.

    If we can capture some of that water instead of losing it, this method would ensure we maximise water efficiency and prevent treated wastewater being discharged into waterways, which is currently undertaken around Sydney including in Wollondilly. Minimising wastewater discharges into waterways means we can better protect those waterways into the future, especially considering the growing population, the corresponding water use, and corresponding wastewater.  

    If stormwater and wastewater are treated and included in our water supply, we will have more than enough water for our needs. Using this recycled water would help protect the waterways and environment, and also increase the resilience of the community. This would enable greener neighbourhoods, and help agriculture and other water dependant industries to flourish. It would mean we are less dependent on rain, and more able to cope with longer, hotter, drier summers.

    Council understands that there has been some sensitivity around the issue in Australia, however, this is likely to change over time – through community education, awareness, and increasing water demand pressures (as demonstrated overseas in London and Singapore).

    Water supply diversification (rather than an over-reliance on one major reservoir) is critical to sustaining Sydney and the surrounding areas. 

    Is water currently recycled for purified drinking water, and can it be trusted?

    Purified drinking water from recycled water to supplement the drinking water supply has been happening for decades and is becoming increasingly common. The following is an expert from a publication from Water Services Association Australia (WSAA) titled ‘All options on the table: lessons from the journeys of others’:

    ‘Formal, planned schemes to purify recycled water for drinking began in the 1960s and are now becoming mainstream across the USA, Singapore, parts of Africa, Australia and Europe. Many produce cleaner water than standard drinking water schemes. Drivers for adopting it typically include resilience to climate change, rainfall independence, drought, strategic objectives like reducing reliance on imported water, cost, and managing wastewater nutrient disposal. Some 35 cities around the world have determined that it is an efficient, safe and sustainable component of their water supply.’

    Why is it important to identify ways to conserve and reuse water?

    With the increasing population and changing climate, there will be increasing pressures on water demand. Therefore it is critical to identify and pursue stormwater treatment methods that support greater water efficiency, and to advocate for wastewater treatment.  Together, these would contribute to a healthier Wollondilly into the future.  

    Why is it important to protect our waterways now?

    The water quality data analysed by Dr Ian Wright (Western Sydney University) confirms that most of the waterways in the Wollondilly are currently swimmable. It is important we maintain and improve the water quality in our waterways into the future as they are an invaluable resource.

    Our modelling shows that this will be compromised if we continue with the ‘business as usual’ approach for new development.

    If we act to protect our waterways now, we won’t need to spend time and resources to retrofit infrastructure to make our waterways swimmable again and restore healthy ecosystems. Retrofitting has a high failure rate due to the constraints of a built landscaping and higher cost need. Ultimately, acting now is more cost effective and environmentally sound. 

    Why do we need an Integrated Water Management Strategy and Policy?

    • WSC has been identified as one of the growth areas for Western Sydney. Therefore, we need to understand the implications of the projected growth and take action to enable a resilient community and environment into the future.
    • We need to ensure the long term protection of:
      • Water supply and conservation
      • High value unmodified creeks and rivers with good water quality
      • High value biodiversity including endangered aquatic fauna like Macquarie Perch and Sydney Hawk Dragonfly
      • High value recreation and amenity
      • Climate resilience and community resilience

    Our strategy and policy provide a framework for smart and sensible water management for an increasing population who will be putting increasing pressure on our water supply and water quality, as well as facing continued challenges such as drought, flooding and bushfires.

    What else will these documents help with?

    The policy and strategy will promote sensible, smart, cost-effective water management within the Shire. This includes:

    • Promote water management infrastructure that are not a resource cost and amenity burden on Council and Community.
    • Promote water management infrastructure that also: benefit biodiversity, support greenspace, reduce heat island effects, improve liveability, water conservation and economic growth and security.
    • Provide education and awareness to stakeholders like the community and other organisations.

    What are the aims?

    • Protection of waterways. We want to achieve a zero impact on local waterways from future development including residential, commercial, agricultural and industrial; and
    • Less water waste; better outcomes for the community and environment. We want to use water as a resource to support sustainable development including community liveability, green neighbourhoods, enhanced biodiversity and climate resilience.

    Who have you engaged with when drafting these documents?

    We have undertaken engagement with the community, traditional custodians of the land, developers, various government departments and Sydney Water.