Is the water always up there?
How does the water get up there? I assume pumps but it all just doesn’t compute in my brain.
In: 1075
Shoutout to the guy in the comments who was wrong about water towers refilling themselves, and instead of just admitting it he quadrupled down and then deleted his account.
I know you’re reading this on an alt or something and I just want to say lol my man, this *truly* did not have to be that big of a deal.
Water prices are typically lower overnight, so they are typically filled then and provide equalization pressure during the day
By gravity and air pressure.
A water tower is like having a bucket of water on top of your house. This bucket has a line coming out of the bottom and is hooked up to your water faucet.
When you turn “on” the water, gravity pulls down on the water along with the air’s weight pushing down too.
The water “flows” to less pressure, so it comes out of your faucet.
As you use up this water in the bucket, it has to be replaced. You could get a ladder and refill the bucket by carrying water to the top of your house and pouring it into the bucket. But this is hard.
It’s a lot easier to “pump” the water up to your roof using a pump and a water hose. A hand pump works but an electric pump works better. This pump has to pump more water up to the roof if the bucket gets too low. This lets the pump “rest” when there’s plenty of water in the bucket.
It’s cheaper to have one giant pump in the water tower than for each building to have their own mini pump.
In places like NYC where there’s a lot of buildings taller than the water tower, the tall buildings do need their own water pumps.
Curious, and no longer an ELI5, but if we assume the water is being fed *into* the tank from a pipe/fixture towards the top of the tank, and if we assume the water leaving the tank does so from a pipe/fixture much lower down if not at the very bottom, as the water *leaving* the tank is being pushed out with the combined pressure from all of the water in the tank above it, would that be enough to overcome gravity and pull more water in from the top pipe/fixture?
In other words, once you have enough water inside the tank, assuming a constant supply of water is available to keep the tank refilled, would it be a self-replenishing system that no longer requires a powered pump?
You’ve got a lot of good answers to this already, so I’ll simply add that tanks on the ground that store water under pressure can accomplish the same thing as a water tower. Generally they will have a pocket of air trapped inside of them that compresses. These tanks are fed by a pump to supply the pressure. The downside to these is that they are more complicated than simply putting something up really high and relying on gravity. That’s the wonderful thing about gravity, gravity never breaks or requires maintenance.
Sometimes there might be less water up there. Ideally it shouldn’t be completely empty, as the absence of water in the pipes can cause problems, but it doesn’t always have to be totally full either.
Yep. Pumps make water go up. It adds pressure to the entire water system making it easier to distribute water everywhere during the highest demand times. During low demand times, the tower fills back up in preparation for the next peak demand.
Think about it this way – you start filling a bathtub with a plug in place. It takes a while to fill completely. You pull the plug, and water starts going down the drain. The water probably drains a bit faster than the tub fills, so the water level goes down. Then you plug the tub again later and it fills up again. The water tower will keep on pumping water into it as long as it isn’t full. If it’s full, the pumping gets shut down to prevent it from getting overfilled. When people need more water, the plug is pulled to share the water from the tower with the rest of the indoor plumbing system.
In areas that are mostly flat with no hills water towers serve to store and provide driving “head” to deliver water. The friction of water flowing through pipes requires energy. A water tower provides energy to over come this friction with gravity. This allows allows sufficient pressure to your house and also fire hydrants, which btw typically set the criteria for how much water to store and how much pressure (the potential demand for fire water flow and pressure).
You pump it up.
Think of water towers like a pressure battery. If the pumps stop then you still have that pressure from the tower to give people water.
A water tower if built as a way to maintain water pressure in a cheap fashion, as well as buffer for times where there is high use.
**Pressurizing water**
There are a number of ways we can pressurize a liquid. One of them is to lift it up high. The higher we place the water the higher the pressure.
Imagine a bucket with a hose in the bottom. That is basically a water tower. We fill water into the bucket and then it stays there until we open the hose.
The water in the bucket wants to go down because of gravity, which in this case translates to pressure at the end of the hose.
If we don’t open the valve at the end of the hose, the water has nowhere to go and will stay under pressure without using any energy. Ready to be used when needed.
**Water buffer**
Depending on how you get your water, there might be a limit to how much water you can get within any given hour. Basically you can’t fill your bucket of water any faster than it fills.
Over the course of 24 hours, you might have more than enough water for your daily needs, but if you have short periods with high use, then the fill rate is not high enough.
We solve this by making the bucket big enough, filling it with water all day. Getting it towards full, when we don’t use much water. Emptying it faster than we fill it when we need a lot of water.
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