Each day, about 350 litres of water is used per person per day in the Wellington region. Flushing the toilet, washing our hands, showering and bathing, doing the laundry, washing up, cooking, cleaning and drinking all require a fresh supply of water. It all adds up. But where does it come from and where does it go?

Our region’s water is best thought of as an interconnected system, rather than defined by city boundaries. When we turn on our tap in Wellington city, we may understandably assume that the water comes from Wellington city and goes back to Wellington city, but the reality of how water works is much more interesting – it makes more sense to imagine water flowing between all areas of the region.

The three types of water – wastewater, stormwater, and drinking water – come from, are consumed in, and are processed across the whole region. People living in the Wellington region receive drinking water from three places – Te Awa Kairangi/Hutt River, Wainuiomata and Orongorongo rivers, and Waiwhetu Aquifer, a natural underground reservoir beneath the Hutt Valley that is fed by river water seeping down into the ground. Greater Wellington Regional Council manage the supply and treatment for all drinking water across the region. When someone flushes the toilet or has a shower in the Wellington metropolitan region (Wellington City, Lower Hutt, Upper Hutt and Porirua), that wastewater is processed in one of three plants at Moa Point, Porirua and Seaview. Stormwater, also known as rain, runs off our roofs, along our kerbs and through underground pipes, and is discharged into the nearest waterway.

When you turn on your tap for a drink in Wellington city, you’re drinking water from the Hutt River. When you flush your toilet in Johnsonville, your wastewater will travel to Porirua for treatment. Our water system is also interconnected because the people of the Wellington region move around for work and recreation. You might live in Upper Hutt and work in Wellington city, so the wastewater from your morning shower is processed in Seaview and the water for your coffee travels along Wellington city pipes and out of the tap at your office. You might live in Wellington city but visit Titahi Bay for a walk and a bite to eat, using Porirua’s water infrastructure as you wash your hands and drink from a water fountain by the beach. Access to work and leisure opportunities across the Wellington region results in a regional community who benefit from shared three waters services, regardless of where they live or pay their rates.

When it comes to stormwater, it is our shared responsibility to make sure only rainwater enters stormwater drains – chemicals from car washing detergents, bacteria in dog poo, and paint all harm the waterways and wildlife that live in and around them. There really are no geographical boundaries when it comes to the water cycle – the water in our rivers and seas evaporate and condense into clouds, which travel and fall back to Earth as rain, which runs into the ground, our waterways, and our drains. Contamination of our water anywhere can impact our water everywhere.

The interconnectedness of the system means rather than focusing on the quality and supply of water for Wellington city, we must care about the quality and supply of water from across the entire region and plan for the future needs of the region. The water system is not divided by the geographical boundaries we have set – its health is the priority of us all and we need to protect it.