Who Can and Can’t Flush the Toilet During a Power Outage

If you’ve ever found yourself in a sudden power outage one of the first things someone in your family will ask is if it’s okay to flush the toilets.

This question has a few “it depends” aspects to it and we’ll cover that below.

As a simple question and answer, here’s the short of it.

Can you flush the toilet during a power outage?

If you have water you can flush the toilet indefinitely if you’re hooked up to the municipal sewer or have a gravity-fed septic and drain field. However, septic systems with electrical pumps to overcome gravity will back-up your lines after a day or two of use. Toilets with electric pumps to flush cannot be used.

Below I’ll discuss the 3 primary setups for where your waste goes, that the type of toilet you have matters, whether or not you’ll even have water to flush, and what you can do to get prepared.

Let’s get started!

Where is your Effluent (Waste) Going without Power?

Before you can find the answer that fits your personal situation, you need to determine exactly where your waste is going. If you don’t do this correctly, you could be in for a smelly surprise!

There are three primary places for your waste to go after you flush:

  • Municipal Sewer System
  • Home Septic System with a level or downhill drain field
  • Home Septic System with an uphill drain field

Municipal Sewer (Yes, You Can Flush Without Power)

One of the joys of being hooked up the municipal grid is that you don’t have to deal with any septic or drain field issues. You don’t have to have it flushed every few year and you don’t have to spend the time locating the access door to it as you dig around your yard like a crazy person.

The other joy is that during a power outage, you simply have to get your waste and water down the pipes and the city will take care of the rest.

As long as you don’t have any pump in your plumbing which is used to overcome gravity in order to get your waste out of the house, then you should be in the clear for flushing when the power goes out.

Septic with a Level or Downhill Drain Field (Yes, You can Flush Without Power)

I am blessed to have this setup. All of the plumbing lines merge into one pipe in my crawlspace and exit the concrete foundation. Everything is sloping on a slight downhill. When outside, my backyard (where the pipe flows to) is sloped slightly downhill from my home.

Everything is gravity fed, and thankfully gravity still works when the power goes out.

With this setup, you are in the clear for flushing when the power goes out.

Septic with an uphill drain field (No, You Cannot Flush Without Power in the Long-Term)

I feel bad for people with this setup. They are removed from the city grid which is a positive step in self-reliance, but they are completely dependent upon an electrical pump to keep their house from backing up with wastewater.

In all honesty, I’d rather be hooked up to the city than have this situation.

You’ll find this setup where the drain field is uphill of the septic (and generally the house itself).

Waste is gravity fed through the plumbing and collects into the holding tank without a problem. This holding tank can store about a day’s worth of water.

This tank then has to get rid of its waste to a septic tank that is located slightly uphill from it. To overcome gravity, an electric pump must be used, since water will not flow uphill.

Without electricity, this pump will cease to function and you’ll have about a day of rationed water use to keep from having that waste water reverse back into your home as the holding tank reaches capacity.

With this type of system you will not be able to flush in the long-term without power. It’s best to install a transfer switch and a generator to ensure that you’ll be able to take care of your business when the power goes out.

Type of Toilet Determines Whether or Not you Can Flush Without Power

Standard Water/Gravity-Fed Toilet (Yes, you Can Flush Without Power)

This is the standard toilet that everyone thinks of when a toilet comes to mind. They have a basin on top, the handle is pushed, and the weight of the water (usually 3/4 – 1 gallon) forces itself down by gravity to whisk your waste away.

There are no pumps and there are no problems with these during a power outage as long as you have water. Don’t worry, we’ll get to that later!

Macerating Toilet or any with an Electric Pump (No, You Cannot Flush Without Power)

These types of toilets are commonly used well after a house is already finished. They are a great for placing anywhere with limited amounts of plumbing and tearing into things.

Because of this, they don’t tie into the beauty of a gravity-fed system like the rest of the plumbing in the house.

When you flush one of these, an electric pump will force the water in the direction that the waste is supposed to go — often straight up — until it ties into the rest of the plumbing.

Even if you could get the waste out of the toilet bowl and past the pump without electricity, you’d then have to fight gravity to get the waste out of the line.

Houses with this type of toilet cannot flush when using this type of toilet. Other toilets and sinks may still be used if they are gravity-fed into a septic or sewer.

Will You Have Water to Flush Without Power?

Now that we’ve covered whether or not it is acceptable for you to push the flushing lever with regards to your toilet and the waste’s final destination, we now have to consider the one thing that makes flushing possible: WATER.

Without water, it won’t matter if you are permitted to flush, since the action will be physically impossible anyway.

You are probably getting your water from one of two sources:

  • Municipal
  • Well pump

Municipal (You’ll Likely Have Water)

Municipal water is generally reliable during a power outage. They use gravity based systems like water towers and have pumps to keep things moving and pressurized.

Moreover, municipalities are generally good at having redundant power sources to ensure that this service isn’t compromised during a typical outage.

Unless something structurally compromised the water lines from the city (earthquake), you should be getting water even though the lights are out.

Combined with sewer access, you can flush to your heart’s content!

A caveat to this is if you live in an apartment complex or find yourself in a commercial building. These places will likely not have water since they will have their own electrical pumps to get the water to each location on their property.

Well Pump (No Water Without a Generator)

With a well pump, you definitely need power to keep it running. Water is pumped up from a well into a pressure tank which generally holds 10 to 30 gallons.

When you turn on your faucet or flush the toilet, water is released from the pressure tank. When the tank gets low, it calls for the pump to refill it.

In a power outage, you’ll have just as much water as you have in your pressure tank. After that, you’ll be out, so use it wisely if you haven’t stored water ahead of time.

To ensure that you have water from your well pump, install a transfer switch for generator hookup. I am able to run mine with a 5 kilowatt generator, but you’ll want to check with a professional for your setup as well pumps are not all created equal.

How to Flush the Toilet when the Power is Out

Simply remove the lid of the reservoir tank and pour the better part of a gallon of water (yours might require more) into it. Flush as you normally would.

You can also pour water straight into the bowl with enough speed that it will instigate a flush automatically. You risk splash-back with this method.

What Can you do to Prepare for Toilet Use during a Power Outage?

  • If you know the storm is coming, fill up a bathtub with water for flushing. Cover the drain with duct tape to stop the possibility of draining. Use a pitcher to move the water from the tub into the reservoir tank for the toilet and use rubbing alcohol to remove residue left by the duct tape after the storm has passed.
  • If you can’t flush, use a 5-gallon bucket or the toilet itself, by lining them with two drum liners. Do your business, throw in some sawdust, cat litter or newspaper, and splash some bleach inside. Fold the liners over until the next use to keep down the smell. I’ll let you draw your own conclusions about final disposal when the waste management services resume their duties.
  • If you can flush but you’re conserving water, only flush your solid wastes and refrain from flushing if you only need to pee. Keep the lid down and the door closed to cut down on the smell. Flush every 3 or 4 pees to keep the bacteria growth (which causes the smell) at a minimum.
  • For hygiene purposes after you use the toilet, keep a large bowl with soapy water on the sink, and another bowl with clean water in the other. Use these for hand washing if you’re conserving water.

Related Articles:

If the Power Goes Out, Does the Water Still Work?

Robert Van Nuck

Robert lives in central Michigan and enjoys running, woodworking, and fixing up small engines.

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