How does water pressure remain even without electricity?

217 views

How does water pressure remain even without electricity?

In: Engineering

Water tanks are placed high. Water is pumped there when electricity is available, then just flow down.

Also, water supply is very important system, so that it can have a reserve power supply line, or set of batteries, which help to outlive the power outage.

The water for immediate use is stored in a water tower or elevated basin. The weight of the water from this height is what creates the water pressure. The city pumps is usually located some distance away and may not be affected by the same power outage. And the water they pump into the system will be pushed up to the water tower for short time storage. If the pumps are out of commision the water tower will slowly drain but the water pressure will remain roughly the same. After a few hours or maybe even an entire day the water tower will drain completely and the water pressure will drop.

Water is usually distributed by gravity aided positive pressure.

If you’ve got a town at a specific altitude, the town water is held as high up as possible, even if it means you pump the water up. From there, when you open a tap, gravity pulls the water down to you.
If the high altitude water supply runs out, and you can’t pump any more water up, you run into problems without electricity.

I’m not sure I understand what you mean.

Like how you can lose power but still have running water?

Depends on the area but those are completely different systems. For you to have running water all that’s needed is power specifically at the water plant and those almost always have back up generators anyways. So if they did lose power it would be fine.

Not to mention water towers and just general aid from gravity.

I assume you’re talking about losing power at your house. Generally the pumping station for city water is pretty far away and won’t have been affected.

If you have a well, there is a ballast tank that holds some water under pressure using an air bladder but once that’s gone there won’t be any water.

During the big Northeast blackout of 2003 much of Detroit had no water pressure because the pumping stations were also without power.

A water tower can also help maintain pressure using gravity until it’s empty.

While all others answers are also correct. Nowadays the water pressure is build up by using large pumps which run on electricity. When the power shutsdown, all water plants generally have a emergency generator to generate electricity and still be able to operate the pumps.

When that last resort is also not available, the pressure remains as is, because it’s basically a closed network (blocked on both sides). However, once you open a water point, the pressure will gradually drop to the point at which finally no water will come out, at least not at high points. You can therefore only tap water at the lowest point in the network in a situation that the pipeline is still filled and there is no electricity.

Have you seen a water tower? Water is pumped up into the tower and gravity provides the pressure. When the electricity goes out as long as there is plenty of water in the tower you will have pressure. I recommend watching the YouTube channel called Practical Engineering. He’s done several videos about water, pipes, water towers, and other types of infrastructure.

https://youtu.be/yZwfcMSDBHs