Understanding what happens to your water supply when the power goes out is a critical responsibility of any homeowner. The key is figuring out the answer before the power goes out. Unfortunately, many of us learn the hard way.
Whether you can use your water supply when the power goes out really depends on the infrastructure of your home. In most cases you can, but it’s not a simple yes-or-no question.
Well Water Versus Municipal Water During a Power Outage
For the most part, there are two primary sources of water for your home: well water or a municipal water source.
If your water supply comes from a private well, the chances are you have an electrical pump. This means, just like any other appliance in your home, the minute your power goes out that pump is no longer functional.
However, the pressure tank and any water heaters inside the home still contain water. The air pressure within your tank continues to push water to your house until that pressure is released. At that point, the pump won’t kick back on until the power returns.
You may need to prime your pump once the power does return.
Fortunately, there are a few backup methods you can employ to get water from a well without electricity—if you have the knowledge:
As with all things prepping, the general idea is to get in front of the catastrophe, so you should consider and plan these backup methods well in advance.
Using a Generator for Your Well Pump
If you’re planning to use a generator as a backup method for your well, make sure it’s powerful enough. Depending on the horsepower of your well pump, generally ⅓ HP to 1 HP, you need at least a 3,500- to 5,000-watt generator.
There’s a high probability that your well pump is wired directly to your breaker box. So, you won’t be able to just plug it into your generator. You’ll need to take the necessary steps ahead of time and have a transfer switch installed.
Backfeeding the power is possible, but definitely not recommended. In most places, it’s not even legal.
In most cases, city water continues to work during a power outage because it’s stored in large water tanks high off the ground. As long as there is water in your local tower, you still have access to that water, since it’s a gravity-fed system.
Unfortunately, there are exceptions to this rule. If you live in an apartment complex or high-rise condominium, chances are your building has its own system that diverts water. If so, and no backup generator is available, then you won’t have access to your local water supply.
You may notice a significant decrease in the water pressure if you live on higher floors, thanks to gravity. At the very least, you should be able to access water at lower levels.
It’s also not uncommon for your water supply to be contaminated during power outages, particularly during storms or natural disasters. So, just because you have access to your city’s water supply doesn’t necessarily mean it’s safe to drink.
Pay particular attention to local news sources during these circumstances and know how to handle such situations. We have a guide to boil notices and contaminated water supplies here.
Using a Shower During a Power Outage
Questions often arise regarding the availability of hot water during power outages. Municipal water sources will continue to work, but you’ll be showering in cold water if you have a tankless or electric water heater.
Fortunately, gas, natural gas, and propane water heaters continue to function normally and are typically not affected by the loss of power. But this is only relevant if you’re dealing with city water.
If you’re on well water, once your tank is empty, without an external power source you no longer have access to your water supply. Portable water heaters are a great option for emergencies so long as you have a backup water source.
Using a Generator for Your Hot Water Heater
Just because you have water doesn’t mean you’ll have hot water. As mentioned, the water in your water heater only stays hot for a short time. It is possible to use a generator to keep your water heater functioning, but the generator must produce more kilowatts than the water heater requires.
For example, a 50-gallon water heater uses 4,500 watts, so your generator must be at least 5,000 watts. And that’s just to run the water heater and nothing else. You can use our generator calculator to determine the exact needs of your home.
Your best bet is to consult a professional electrician ahead of time to determine your specific requirements.
Sadly, if your home has a tankless water heater, a portable generator simply isn’t powerful enough. In many cases, a portable water heater is the preferred backup plan.
Using Your Toilet During a Power Outage
In most cases, toilets are not affected by power outages. If you are on municipal water, they should function normally. The only issue would occur if you’re on city water but have a pump-assisted septic system. In this case, you only need to limit your flushes to avoid a sewage backup as noted above.
If your property functions on well water, your toilet reservoirs won’t fill once the water heater is empty. Rest assured, you can still flush your toilets manually as long as you have a backup water supply (which you should). Simply pour water directly into the toilet bowl or the reservoir, and then flush as normal.
Of course, there’s always an exception to the rule. If you have a pump-assisted toilet, which many basement toilets do, you can still flush manually, but the sewage concerns noted above would still apply.
Similarly, if your house has a grinder pump that prepares household waste for sewage, you have limited flushes before your pipes start backing up.
If toilet use is a big concern, plan for alternatives, such as camping toilets or disposable toileting bags.
What Happens to Your Waste Water During a Power Outage?
Equally important to having water is adequately disposing of wastewater.
Using the available water in your well pump or water heater may result in a sewage backup under certain circumstances, threatening your access to water.
If you have a traditional gravity-fed septic system with a tank and leach line, there won’t be any issues. However, if your home utilizes a septic tank pump, pump grinder, or sump pump, you need to significantly limit the amount of water you use during an electrical outage.
If your power is out for less than 24 hours, you’re probably fine. But anything longer and you may have issues, especially if you have a large family.
If you have one of these pump-assisted septic systems, you need to be very water conscious. They all require electricity to pump waste from your home to your septic:
- Drip distribution
- Mound systems
- Recirculating sand and filter systems
- Some wetland systems
If you’re uncertain what kind of system you have, there are a few ways you can find out.
- If you know for certain your drainage field is higher than your septic tank, you have a pump-assisted system.
- Ask the listing agent or previous owner.
- Research city/county zoning regulations and/or records for permits.
- Have the system inspected by a professional.
Likewise, if your home utilizes sump pumps or pump-assist toilets, the same concept applies. Because any wastewater is typically pushed to your drain field by way of an electric pump, extended outages could result in a backup of sewage into your home.
Simply put, without electricity, your sewage isn’t going anywhere. So, during outages expected to last more than 24 hours, here are some tips:
- Avoid letting faucets run
- Flush as little as possible
- Limit bathing and laundry
For basement sump pumps and pump-assisted toilets, a simple backup battery is well worth the investment. You could even have a backup power supply professionally installed for your pump-assisted septic system.
To use water during a power outage, you should know the ins and outs of your own water system and have all the necessary backups in place before you have to deal with a long-term power outage.