If We All Flushed Our Toilets At The Same Time

What If Everybody In Perth Flushed Their Toilets At The Same Time!

If we all flushed our toilets at the same time you would suspect we would be flooded by wastewater and I think you might be right. As far as I know no state or country has ever tried. It might be a hoot and we can’t for sure know what the outcome might be but we can take a pretty good guess. It’d probably be ugly. The average home in Perth is fitted with sewer pipes around 100mm in diameter.

The pipes from your home are connected to subdivision systems, which connect together at street systems. Street systems tie into road systems, which go to main road systems, and, ultimately, wastewater treatment plants. Underneath your town is a wastewater system as complex as a spider’s web. The closer you get to the treatment plant, the larger the inside diameter of the pipes becomes. So a 100mm pipe from your house connects to a 150mm pipe and so on. The pipes can hold a lot of water, but can they hold enough for everyone to flush at once?

Perth’s Sewer System Would Suddenly Be Inundated With 4,000,000 + Litres Of Wastewater

If everyone in Greater Perth ‘s 700,000 (approx.)households all flushed just one toilet at the same time, and each of those toilets expelled 6 litres per flush, then Perth’s sewer system would suddenly be inundated with 4,000,000 + litres of wastewater. And we’re not even counting all of the public toilets in the city. Of course, the earth isn’t level underneath many cities, and to overcome changes in elevation, sewer systems use pump stations, wastewater plants that push sewage uphill toward its final treatment destination. These stations would be the first overwhelmed by unanimous flushing. There would simply be too much wastewater trying to pass through the pipes at the same time — kind of like trying to force an orange through a drinking straw — and the flow of sewage would stop. Sewage already past the pump stations would return downhill, and as the pump stations flooded, the lines leading to them would back up. Eventually, this sewage would find its way to the place where this whole debacle originated — your home.

Backflow valves probably wouldn’t help. Not only would your toilet overflow, but so, too, would every wastewater line in your home, including your shower, kitchen and bathroom sinks, and even your dishwasher and washing machine. Outside, the manhole covers dotting the street would also flood and overflow, leaving people in sewage possibly more than ankle deep. Depending on how many people live in your city and how large the sewer pipes are, it could be even worse. Wow! Could you imagine that? So as not to worry you this could be all hypothetical and my assumptions could be completely wrong, but best to buy a small rubber dinghy just in case.