How to Build a Legit Off Grid Water System [2020 Guide]

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guide to building an off grid water system

In our modern day society, we have ample access to cheap and (mostly) filtered drinking water; off grid water systems are practically non-existent in cities and suburbs.

All we have to do is turn on the faucet and the clear cool liquid comes pouring out to our convenience. Turn the faucet slightly and warm water is at our disposal. What a luxury!

We do forget that access to clean water is a luxury – until that water runs out.

We’ve all had this happen before: a water mainline goes down in town. You go to wash the dishes, and nothing comes out.

At that moment, it feels like the biggest inconvenience in the world! You then keep going back to the faucet or to use the toilet or to shower for that matter, forgetting that the water is off.

Each time when the water doesn’t come, that feeling of annoyance is there, along with a small feeling of dread (when will the water come back?).

Over 24 hours of being cut off from water create a twinge of panic… The dishes start to pile up, you need to take a shower…  Oh, when will the water come back? This is ruining my life!

dirty dishes piling up in sink remind us of taking municipal water for granted

These are the few and far between moments that make us realize how wonderful it is to have functional on demand plumbing.

When going off grid, the luxuries of living that we have grown to consider as basic amenities becomes an obstacle asking for a solution. How do we set up these basic systems? What if a water source is not readily available? How do I keep my water from freezing over in the winter?

A little ingenuity and engineering can go a long way and can be applied to any off grid situation, even if water is sparse.

In this guide, I will cover methods and ideologies so you can build an off grid water system correctly.

Let’s dive right into it!

Essential components for building an off grid water system

Regardless of how you get your water, there are a few essentials that any system will need:

  • Pumps – submersible, pumps for pulling/pushing water
  • Electricity for pumps – wired in, solar, wind
  • Pressurized water tank – for water pressure
  • Water tank – Cistern, holding tank, transport tank
  • Hoses and pipes

Special note:

you can eliminate a lot of costly components by leveraging gravity for your water system.

If you can manage to source your water uphill from your home, you may not need a pressure water tank or even pumps.

I go into a bit more detail on off grid gravity water systems in my off grid water pumps guide.

Choosing the water source for your off grid water system

Using a Wild Water Source

Consider yourself lucky if you have water flowing through your property year-round.

In many situations, the water source will be lower than the house and will require a pump to push the water uphill. Sucking the water uphill will only go for a couple of dozen feet whereas pushing the water can go for longer lengths.

I have written a guide to building an off grid water pump system for some ideas.

year around flowing stream for off grid water
A year-round stream is an ideal off grid water source

There are a lot of factors to consider when using your property’s water source as your off grid water system.

  • How far does the water have to travel?
  • Are there obstacles to overcome when running your pipe?
  • How will you run power to the pump?
  • How many particulates are in the natural water; is it crystal clear and flowing or is it standing and murky?
  • Does the water source last year round?
  • Does the water source freeze over the winter?

Once you have figured out your obstacles, you can make a plan to overcome them.

Pumping water from a wild water source

Unless your water is at a higher elevation from its destination, you will need to leverage pumps to move your water.

The first thing to consider is how large of pipe you need to run.

When running your pipe from the source to the house, you need to factor in:

  • How far the pipe runs – for a 500 foot run, pipe should be about 2 inches diameter.
  • 90 degree angles – sharp angles cause strain on the system so try to design your pipe to be as straight and direct as possible.

Running Power to an Off Grid Water Pump

Running power to the pump requires some thought as well; having to run a power cord for hundreds of feet is really not an ideal solution.

One idea is to run the electrical cords through a buried PVC conduit. You can directly wire into your breaker box (if you are a handy electrician), run the cabling through the conduit, and have a GFCI protected outlet with cover popping out of the ground. Then you can plug in a cord to your pump.

diagram of how to run electricity to water pump

Try not to bend the electrical cord too much as you do not want to exceed 360 degrees of accumulated angles.

Alternative energy sources come in very handy for powering pumps if your water source is too far from the destination.

solar power panels providing energy to water pump

If you have enough sun, you can consider using a solar power water pump. You can also try a wind turbine if you live in a more windy area or even a small hydropower setup.

I have written a guide on how to build a DIY solar power drip irrigation system that goes over how to connect solar power to your water pump.

Using a Submersible Sump Pump Off Grid

You don’t just want to throw your submersible pump into the water source and hope for the best.

If too shallow, the pump will fill with debris and won’t have enough water flow and pressure to keep pushing the water.

Dig a hole by the water source that is deep enough to keep the pump fully submerged at all times. This mini pond will also help sift debris and silt when filling up.

screen for filtering debris from water pump

You will want to protect your submersible pump from clogging up with debris. You can get a prefabricated screen for your pump or make a homemade filter from a large bucket with holes pilfered into it.

If your water source does not last year around or freezes over the winter, you will need another source for those unproductive months. An off grid water tank will also help get you through dry seasons.

Install an Off Grid Well Water System

Having a well on your property as your off grid water system is an ideal choice for year-round water at your fingertips.

Once the well is installed it requires a very minimal amount of work, although water pressure can be an issue. You will need to use a pressure water tank. You will also need to keep an eye on your sump pump and maintain it from time to time.

Installing a well uphill from the house can eliminate the need for a pump and pressure tank and makes the system completely self-sustaining.

old well

However, having a well may not be the end all be all solution to your water system. There are many downsides to consider.

Disadvantages to having a well on your property

Expense –

According to Home Advisor, drilling a 150 foot well costs an average of $5,500 feet. And that is just the drilling expense! If you decide to have all the components installed for you such as the casing pipe, pressure storage tank, water treatment, and water heater, you are adding an additional expense of $4,000 to $10,000. A complete artisan well system can be around $10,000 to $20,000.

Well water quality issues –

Just because your water comes from the ground, doesn’t mean its any good. A range of contaminants commonly found in well water:

  • Dissolved minerals and salts like calcium, magnesium, and sodium. These minerals cause hard water and can cause skin irritation and eventually ruin appliances and clothing.
dissolved minerals make white deposits on leaking pipe
  • Heavy metals and trace elements. Iron, lead, radon, and boron are all common metal contaminates in well water.
  • Chemicals and nitrates from farms. If your property is near a farm, take heed that pesticides and fertilizers can leach nitrates and phosphates into your groundwater.
  • Cryptosporidium and E Coli tend to be at higher risk in well water. This tends to be more of a problem for shallow wells. The deeper the well, the less likely for these pathogens to occur.

Well water can also be discolored, cloudy, have a bad taste or odor. All of these could be a sign of contamination and toxicity and will need to be researched.

Wells can dry up –

It would be a huge pity to spend thousands of dollars on a well to only have it decrease production or cease entirely.  Drought can be a cause of decreased well water production and some wells simply dry up over time. The lifespan of a well is only 20 – 30 years, so plan accordingly.

There are usually telltale signs when your well is going dry. There could be a change in taste. The sediments that have built up in the bottom of the well that become concentrated as the water supply drops. Other warning signs are pumps that are having to run longer and harder, sputtering faucets, and murky water.

Problem wells can sometimes be solved by deepening the well or lowering the pump, but an inspection may have to determine the best solution.

Hand digging a well

Wells don’t have to cost a fortune. If your water table is shallow enough, you can hand dig a well.

Just keep in mind that shallow wells are more susceptible to contaminates, so filter and purify your water accordingly.

drawing of hand well pump system

Collecting rainwater in Barrels

Collecting rainwater may not be your primary source of water but can be a great backup. In some areas, if you have a large enough storage system, rainwater may be enough to sustain your off grid water system year-round.

The best way to capture rainwater is to use a large surface, such as a roof, to guide the rainwater into a collection barrel. This can be done by installing gutters around the perimeter of the roof, then installing a downspout that pours the water into a barrel.

Barrels designed specifically for catching rain have a hose spout on the bottom, therefore the barrel should be elevated from the ground. A pump can be attached to the spout and the collected water can be stored in a larger holding tank, or a succession of barrels can be attached to each other for storage.

rainwater barrel water collecting system

Take heed that your rainwater will need to be purified. This is mainly due to rogue bird turds that can end up in your water.

Off Grid Water Tank System

A water tank system where you haul in or have fresh water delivered may be your only option or a temporary solution while working toward another water system.

water tank system

No matter what water system you have, having a holding tank that will accommodate at least a few days of potable water is pretty important.

Transporting the water from source to tank

An off grid water system that requires hauling in water can come from a nearby water source like a spring, river, creek or lake, which will still require filtration. Water can also be attained from a nearby municipal water source such as an RV dump site.

Some areas offer rural water delivery for a fairly affordable price, but many areas, especially extremely remote or hard to reach properties, will not have this service and you will have to haul water in yourself.

If you are hauling in your own water, you will want to have a truck with a tank installed or a trailer to haul the tank. A great choice for a water tank is a food-grade IBC tank. This eliminates the hassle and cost of hauling around barrels.

food-grade IBC tank for transporting water

IBC tanks are sturdy, sloped at the bottom for full emptying, have a drain spout on the bottom, and have a removable lid on the top. The tanks are enclosed in an aluminum cage for easy loading, unloading and securing. They are also square which makes a 275 gallon tank fit easily on the bed of a truck or trailer.

You can buy a new 275 gallon food grade IBC tank for around $500. Refurbished and reconditioned IBC tanks go for the $200 mark. You can purchase a non-food grade tank for even cheaper but that is ill-advised.

water tank prefabricated to fit truck bed

There are also prefabricated tanks specifically designed to fit on the bed of a truck. This 305 gallon tank is molded to fit over wheel wells and has an aerodynamic design.

Calculating the size of the Cistern Tank

When choosing a water tank, you will want to account for how much water is used daily. If you use 10 gallons a day and want 7 days of water storage, then you will want to purchase a tank that holds at least 700 gallons.

Keep in mind storing extra water than what you plan for can help in unexpected situations like a long term draught or fighting a fire. You will want to keep your cistern with at least 50% capacity as well to keep up the unit’s strength.

Therefore, if you want 700 gallons stored, may as well purchase a 1,000 gallon tank.

You will want to consider how you will store your tank. You can store your tank outside above ground, below ground, or in housing.

An above ground tank is fine if you have the room and your climate is mild throughout the winter. If you need to conserve on room or you live in freezing conditions, then placing your cistern underground is a good choice.

Installing an Underground Cistern Tank

When choosing the underground option, you need to purchase a cistern that is designed for subterranean use. There is extra pressure from the weight of the soil that an underground cistern is specially designed to handle.

An underground cistern tank
An underground cistern tank

Place your cistern at a minimum of 12-28″ depth to keep pipes from freezing upon entering and exiting the unit. You may have to place your tank deeper, depending on how deep the ground freezes in your area.

The downside of having your tank underground is limited access. If there is a problem with the tank, you will have to dig it up.

Tanks also require yearly cleanings so once a year, you will need to access the tank.

Check with your cistern manufacturer to see the maximum depth that the cistern can handle. It can only be buried so deep to withstand pressure from the dirt.

If installed too deep, the sides of the cistern can crumple. 

Pressure Water Tanks For Water Pressure

Unless you can place your water source at a steep enough incline from your homestead, you will need the help from a pressure water tank to give you the water pressure you need for your off grid water system.

pressure water tank

A pressure tank works by creating water pressure from compressed air that bears down on the water. When the valve gets opened, the water is forcefully pushed from that air in the tank.

Once the pressure drops to a certain low, the tank’s water pump turns on and more water fills the tank; this is the cycle of the pressure water tank.

The larger the tank, the fewer cycles, therefore less runtime.

The proper sizing of the tank is crucial to limit premature pump failure. When in doubt, go larger.

Calculating Pressure Water Tank Size

  1. Determine the Gallons per Minute (GPM) of your pump. This will be given by the manufacturer. This is known as your Flow Rate. Let’s go with 5 GPM for the example.
  2. Calculate the hours of water use per day. This is known as your Runtime. Calculate in your showers, dishwashing, handwashing, toilet flushes, and any appliances that use water. For convenience, let’s go with 5 hours per day.
  3. Know the cut-in cut-out PSI of your pressure switch. This could be an unknown variable as you may not own a pressure tank yet. Let’s go with a standard of 40 PSI.

Now apply this calculation:

Flow Rate * Runtime = Tank Drawdown.

Tank drawdown is not tank volume; the drawdown is the amount of water stored or delivered between the pump shutting off and restarting.

In our example, our drawdown capacity is 25 gallons. We need to make sure that the pump we are using matches the drawdown capacity of the tank we purchase.

0 – 10 GPM pump requires a 10 gallon drawdown.

11 – 20 GPM pump requires 1.5 times the drawdown. Example: 15 GPM pump * 1.5 = 22.5 gallon drawdown.

20+ GMP pump requires 2 times the drawdown. Example 25 GPM pump * 2 = 50 gallon drawdown.

We also need to figure out the PSI of the setting. The most common PSI settings in a pressure water tank are 30/50, 40/60, 50/70.

Note that the low number is the pressure when the pump turns on and the high number represents the pressure when the pump turns off.

Here is the chart to figure out the PSI setting in relation to tank size.

Chart of PSI setting in relation to tank size for pressure water tank

For our example, our 25 gallon drawdown capacity need is met with an 81 gallon tank at 30/50 PSI. I would air on the side of caution and bump that up to an 86 gallon tank.

Calculations courtesy of

Off Grid Water Filtration and Purification

No matter what system you choose, all the water flowing through your off grid water system will need to be filtered.

A spring could be an exception if there are no possible ways of contamination, such as wild animal contaminates or farms being nearby. Even rainwater needs to be filtered as bird droppings and debris can gunk up the water.

The cloudier and murkier the water, the more layers of filtration will be required. Crystal clear snowmelt from the mountains of Montana will require far less filtration than the warm murky waters of the South.

You will also need to purify drinking water to eliminate microbials such as bacteria, viruses, and cysts.

I have written a handy guide to off grid water filtration and purification. Check it out!

I hope you have enjoyed my off grid water system article both informative and enjoyable.

If you want some more off grid water ideas, check out Off Grid Maker’s article.

I would love to hear about your water systems, please leave a comment below!

Regina, owner of Maximum off Grid

Hi, I am Regina, the creator of Maximum Off Grid.

My goal is to teach you how to become more self-sufficient, no matter how small the change.

Please feel free to reach out to me with any questions or comments.

Have a great day!

Regina Caligiuri

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