Caring for our water
When it rains in urban areas, water often makes its way into the sewer system. During heavy rainfall, the volume of water can exceed the capacity of the sewer system, leading to tanks overflowing into nearby rivers and streams.
Below, there is a simulation that illustrates bathing water quality in a river affected by occasional discharges from storm overflow tanks. Press the ‘Heavy rain’ button to simulate a period of continuous heavy rainfall, which increases the flow rate in the river and causes discharges from the overflow tanks. This causes water quality to deteriorate downstream, indicated by darker colours in the simulation.
Improving water quality with community action
There are lots of ways that the community can help to reduce the impacts of heavy rainfall. One way is to use water butts to collect rainwater from roofs, which can then be used for gardening or other non-potable uses. This reduces the amount of water entering the sewer system during heavy rainfall, helping to prevent overflows.
Trying adjusting the number of water butts in the community using the slider above to see how this affects water quality in the river during heavy rain events. Don’t forget to press the “Heavy rain” button again to see the effects!
A complex system
In reality, the interactions between rainfall, sewer systems, and river water quality are complex. There are many other community-scale interventions that can help to reduce the impacts of heavy rainfall, including picking up animal waste, maintaining septic tanks, and … . These interventions can help to reduce the amount of water entering the sewer system during heavy rainfall, improving water quality in rivers and streams.
We’ve included some of these complexities in the simulation below. Drag the various sliders to see how many different factors can influence water quality in the river during heavy rainfall. Press the “Heavy rain” button below to see the effects.
FAQs
Q: Why does heavy rain affect water quality in rivers?
A: During heavy rainfall, the volume of water entering the sewer system can exceed its capacity. This can lead to overflows from storm tanks, which discharge untreated sewage into nearby rivers and streams, introducing harmful bacteria and pollutants that degrade water quality.
Q: How do water butts help improve water quality during heavy rain?
A: Water butts collect rainwater from roofs, reducing the amount of water that enters the sewer system during heavy rainfall. By lowering the volume of water in the sewers, water butts help prevent overflows from storm tanks, thereby reducing the risk of untreated sewage being discharged into rivers and improving water quality.
Q: Can individual actions like using water butts really make a difference?
A: Yes, individual actions can collectively have a significant impact. When many households use water butts, the cumulative reduction in water entering the sewer system can help prevent overflows during heavy rainfall events, leading to better water quality in local rivers and streams.
Q: Are these simulations based on real data?
A: The simulations are simplified models designed for educational purposes. While they capture key concepts related to water quality and sewer overflows, they do not incorporate all the complexities of real-world systems. They are intended to illustrate how factors like rainfall and community actions can influence water quality in rivers, rather than provide precise predictions.