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Rainwater Collection Tanks for Tiny Houses – A to Z Guide 2024

Harvesting rainwater for your tiny home isn’t as complicated as you imagine it.

It is as simple as collecting water in an open container on a rainy day.

However, if you’re looking for a robust solution about how tiny houses get water, then you this solution will keep you off-grid.

Most people learn that setting up a rainwater collection system is surprisingly easy.

And in case you’re feeling motivated, you can even go the DIY route by building your very own rainwater collection system.

So, the big question is how can anyone set up a rainwater collection system for their tiny home?

What are the best rainwater collection tanks for tiny homes?

Well, read on as we will bring you up to speed on everything you need to know about the tiny house rainwater collection system.

To give you a bit of a background, when harvesting rainwater for tiny homes, you’ll need basic components like a catchment area, the first flush diverter, downspout, pressure pump, and of course, a rainwater tank or storage bin.

If you’re not particularly sure how to get started, this article will provide you with all the details to kick off.

Plus, we will show you all the nitty-gritty of rainwater collections.

Also, we will clear some misconceptions about the legality of rainwater harvesting across different states in the U.S.

What are some of the best ways to store rainwater for your tiny home?

When it comes to rainwater storage for tiny homes, there are plenty of options available to you.

But before you decide on the best rainwater storage option that works for you, make sure you know your consumption needs.

Most tiny house owners use the following options for rainwater collection:

  • Rain pillow
  • Trash bins
  • Soft PVC container
  • Barrels
  • Intermediate bulk containers totes
  • Plastic drum

If you want something that will last for a while, especially something that is more permanent and provides a large carrying capacity, you won’t be disappointed to opt for your own water cistern.

This option will most likely provide your daily household water needs.

What we particularly love about rainwater storage is that it is passive.

What we simply mean is that it requires little to no maintenance once the system is set up.

But before you opt for a rainwater tank for your home, we would encourage you to buy pumps with filters or build your own using DIY objects.

This is to ensure that the rainwater you collect for your home is clean.

Also, you’ll need to take some precautions, especially if you live in colder climates.

Why is it important to winterize your rainwater collection system?

If you plan to prevent damages to your pipes and overall rainwater harvesting system, then you’ll need to take necessary precautions such as winterizing your rainwater harvesting system.

As per the standard winterization protocol, the first thing you’ll need to do is drain off your rainwater containers.

This will include draining off all the pipes and supply lines leading to the catchment system.

If your goal is to use your rainwater collection system all through winter, the first thing you want to prevent is water stillness.

A simple way to do this is to include an aerator in your collection system.

This helps to provide consistent air to your rainwater tank, preventing it from freezing.

Another way to go about this is to install a heat pump along with your rainwater collection system.

This will ensure that your water containers do not fall below a specific temperature.

Some tiny house owners prefer the old-school way of installing a rain collection system near a shed.

This provides them with an opportunity to heat up that area to prevent the water in the tanks from freezing.

Whatever the case, it’s crucial to keep your rainwater collection system supply line heated or buried.

This will prevent the pipes from bursting.

Is it possible to collect water during winter?

It’s absolutely possible to collect water during the winter.

That said, if you don’t have a robust system in place, the best thing to do is to drain your supply.

To save the water you have collected through the rainy season, we suggest transferring the rainwater into smaller containers.

Essentially, you want to transfer these containers into your home.

We suggest opting for containers with a spout as they are great for collecting water for everyday use.

In what state is it illegal to harvest rainwater?

If you aren’t planning to build a reservoir or dam on your property, we doubt if you’d have any runnings with the law.

Most of the stories we have read about illegal rainwater collection are either exaggerated or happened on a larger scale than the law permits.

To set the record straight, rainwater collection isn’t illegal in the US.

More so, some states encourage residents to tow this path.

That said, there are some restrictions that exist across a handful of states.

In some locations, the government has a specific limit on the amount of rainwater you’re allowed to collect.

For instance, in a state like Utah, unregistered individuals are only allowed to collect 100 gallons of water.

On the flip side, registered individuals are allowed to collect up to 2,500 gallons.

From our research, here are some of the top states that have no restrictions on rainwater collections

Florida, Alabama, Rhode Island, Hawaii, Alaska, Maryland, Connecticut, South Dakota, Michigan, West Virginia, Tennessee, Indiana, Vermont, Virginia, Minnesota, Oklahoma, New York, Maine, Wyoming, Iowa, Nebraska, Washington, Montana, Mississippi, and more.


Rainwater collection system: Important parts of a rainwater collection system

Knowing the integral parts of the rainwater collection system will allow you to build your setup correctly.

Here, take a look at all the important parts of a rainwater collection system.

The catchment area

The catchment area is the surface where the rain first hits.

For tiny homes, the catchment area is usually the roof.

If you live in a tiny house with a flat roof, it will be wise to set up a separate collection area on your property.

The catch is, if you have more surface area, you will be able to collect more rainwater.

Over the years, steel roofs have proven to be the ideal roofing options for a tiny house for harvesting rainwater.

Plus, steel roofs are easy to clean.

Also, they aren’t treated with harmful chemicals that can impact the quality of water you’re collecting.

Thanks to its smooth surface, a steel roof will allow the rainwater to nicely roll to the gutter and straight to the downspout.

This improves water collection tremendously.

We are sure you must be wondering where you can get quality steel roofs.

Well, the answer is pretty simple.

You can get top-quality corrugated steel sheets directly from your city’s local hardware store.

And in case you want to save some extra bucks, you can opt for scraps or use old steel sheets from your tiny house build.

For tiny house owners who don’t want to stress themselves, you can simply buy corrugated metal roof sheets online.

The downspouts

The downspout connects your gutters directly to the storage areas.

And guess what, you can build a simple downspout using a flexible pipe.

And in case you don’t want to go that route, you can simply buy a downspout that is built specifically to collect rainwater.

When buying a downspout, keep in mind that it comes with two separate items like diverter and filter.

These two items are connected to the downspout.

You can think of the diverter as a separate outlet that effectively separates dirty rainwater from clean water.

The filter for downspout is usually made from a mesh.

However, if you want something more intricate, something that can keep insects, debris, and other residues away from your water, you’ll have to pay a little more.

First Flush Filter

Besides using a mesh filter, you’ll need to install an additional filtration system.

This is important as it will help redirect the first flow of unclean water away from your catchment system.

For those asking if you can filter rainwater harvested from your roof, the answer is YES.

To do this, you’ll need a first flush filter.

The first flush filter, also known as a rain barrel diverter, is a pretty popular contraption that links the downspout to the collection area.

Most times, the first flush filter is made from PVC material.

It usually features a ball that floats around inside.

The purpose of the ball is to seal the hole, allowing for cleaner water to sieve through your rainwater storage system.

In case you’re wondering how a rain barrel diverter works, you’re welcome to read further as we have all that figured out.

Here is the catch.

The first flush of water usually contains dirt, debris, and other residues.

As the rain keeps cleaning the water, what happens is that the tube gets filled up with cleaner water.

This is followed by the foam ball rising to seal the hole, diverting cleaner water to the storage chamber.

Collection area

In case you’re wondering what the collection area is, it simply refers to your water storage units.

Anything from a trash can to repurposed barrels, or storage tanks used to harvest rainwater is referred to as the water storage unit.

While most tiny home owners prefer using the standard 55-gallon drums, which they can connect to PVC pipes for easy water collection, others prefer using large capacity drums.

Most off-grid homes who depend entirely on harvested rainwater for everyday use prefer deploying a 275 gallon IBC totes.

At the end of the day, your collection area simply depends on:

  • How much water you use daily
  • How often you would like to use rainwater.

If you plan to move every now and then, you’d most likely need to get portable storage options.

Another question that comes up a lot when discussing collection areas is whether the rain barrel needs to be elevated.

Regarding that, here is all you need to know.

When you’re setting up the rain barrel, elevation isn’t the goal here.

Your goal should be stability.

To achieve this, you’ll need to install your rainwater collection on a solid foundation.

This way, you can be rest assured that it won’t flip over during rains or heavy storms.

If you don’t want to use repurposed drums, you can purchase IBC totes or rain collection tanks online.

For tiny house owners who don’t want to go overboard with their budget, you can buy second hand containers.

However, when going for these options, make sure the old containers weren’t used to store harmful chemicals, as this could affect the quality of water you harvest.

If you don’t mind going overboard with your budget, we highly recommend buying RainWater Pillow Kits.

A 1000 gallon pillow kit should cost you nearly $2,800.

And yes, it includes all the necessary accessories including flush diverter, downspouts and others.

Pressure pump

If you’re not convinced that gravity will be enough to push the rainwater all the way to your collection chamber, it won’t be such a bad idea to install a water pump or pressure pump to help get the job done.

And the cool part is that you don’t have to buy a $200 to $300 pressure pump.

This is because, since you’re only collecting water for your tiny home, a simple pressure pump should get the job done.

To give you some idea, you won’t be disappointed to get a 250 gallons per hour pressure pump.

Also, a decent barrel water pump should get the job done without costing you a fortune.

Rainwater harvesting laws

While there are no stringent laws regarding rainwater harvesting, we are sure you don’t want to have any issues with regulations.

That’s why you need to do your due diligence to ensure you’re in the good books of the law.

Just to give you a bit of a background, it will interest you to know that rainwater collection laws vary by state and that’s because some states consider rainwater to be property of the state.

In such states, you’ll need to get approval before you can harvest rainwater.

Before you go ahead to install a rainwater collection system, it’s best to reach out to local authorities to know what you can and can’t do.

This will save you a lot of headaches.

Top 10 catchment rainwater tanks

Now that you know a thing or two about rainwater collection, it’s time to take you through our list of top catchment rainwater tanks.

This will help you decide which rainwater tank is best for you, especially with your lean budget.

53 Gallon Portable Rain Barrel Water Tank

If you don’t want to go overboard with your budget and want something that is simple and affordable, you’ll absolutely love this brilliant rain barrel water tank.

This portable and collapsible water tank is easy to install.

Plus, it won’t cost you a fortune to have this installed in your home.

Thanks to the detailed instructions provided by the manufacturer, you’ll be able to set this up yourself.

And yes, it is eco-friendly too.

This makes it great for people who want to save our darling planet.

Good Ideas RW40-OAK Rain Wizard Rain Barrel 40-Gallon

This is another brilliant rainwater collection barrel that should work pretty well in your tiny home.

Though it is pretty small and can only collect 40 gallons of water, it should be perfect for your tiny house water needs.

Made from superior brass materials, this water collection tank is durable and should last some time.

It also comes with a hose hookup and overflow spigot.

Its unique screen is designed to keep insects, debris, and animals away.

Though it is compact, you can link it to other barrels to increase capacity.

Its rotationally molded hold prevents cracking and splitting.

And yes, you won’t have to spend a fortune to get this barrel.

Blind Box Rain Barrel 100 or 50 Gallon Collapsible Rainwater Collection System

This collapsible rainwater collection tank is a must have for any tiny house owner looking for a tank that is compact and easy to install.

This superb rainwater collection system can be used to store 50 to 100 gallons of rainwater, which should suffice for your tiny house water needs.

This rainwater storage barrel is made from quality PVC frame and anticorrosive PVC mesh.

This makes it perfect for all seasons, including winter.

RomoTech 82124269 Polyethylene Reservoir Water Storage Tank

If you’re interested in a large capacity water storage tank for harvesting rainwater.

This is the one for you.

This incredible polyethylene reservoir is built to store at least 550 gallons of water, which should be enough to handle your household water needs.

Its thick walled and heavy duty design means that this rainwater tank is built to last.

It is also pretty translucent, giving you a clear visibility of the water inside.

The only caveat is that it is more expensive than other water storage tanks we have highlighted so far.

Vestil IBC-330 Steel Intermediate Bulk Crate, 330 Gallon Capacity

This bulk crate is superb for harvesting rainwater.

Its remarkable design makes it perfect for tiny homes.

For tiny house owners who want to keep things simple, this water storage crate should get the job done.

And yes, it can be used to store at least 330 gallons of water, making it a brilliant option for your tiny house water needs.

Plus, it is durable and easy to install.

RainFlo Corrugated Steel Tank Systems

If you don’t want to use plastic-based rainwater storage tanks, instead prefer steel tank systems, you’ll love the all amazing RainFlo Corrugated steel tank system.

In terms of capacity, this impeccable tank can hold between 800 to 1000 gallons of water.

And yes, you can also get tanks that are customized to your needs.

When installed, this tank can serve you for many years down the line without any hassle.

Heritage water tanks

Heritage water tanks are a brilliant option for harvesting rainwater.

Their steel based water tanks are one of a kind and built to last for many years.

Depending on your tiny house water needs, you can get either a small capacity steel water tank, or a much larger one.

While these tanks can be installed using the DIY approach, it won’t cost you a fortune to get a professional to install this tank.

Plus, the company offers installation services.

Aquaplate steel water tanks

If you’re on the market for a steel tank that can hold insane gallons of water, you won’t be disappointed to give Aquaplate steel water tanks a try.

An average steel water tank can hold up to 3,600 gallons of water, which should be more than enough for your tiny home water needs.

The only issue we have with these types of tanks is that they are quite expensive.

100,000 Liter Aqualine Steel Liner Tank

This 100,000 liter water tank is superb and large enough to handle your tiny house water needs.

The materials used to build this tank are solid and will last you many years.

In terms of maintenance, this storage tank for harvesting rainwater is easy to clean.

Plus, it is designed to prevent algae build up.

Though it is pretty expensive, you can count on it to solve your tiny house water problems, especially if you live off-grid.

20,000 Liter Aqualine Steel Liner Tank

Looking for a moderate sized steel tank you can use to harvest rainwater?

This is the one for you.

Built to store 20,000 liters of water, you are rest assured that this storage tank will store enough water to last you for many months.

Frequently asked questions

What’s the best storage tank for rainwater collection?

With the myriads of options available, it will be pretty hard to determine the best storage tank for rainwater collection.

At the end of the day, you need to opt for something that is in line with your budget and provides you with enough capacity to store rainwater.

Can I install rainwater storage tanks myself?

Installing rainwater storage tanks can be a little tricky, but guess what, you can do it yourself.

You can either follow the instructions provided by the manufacturer or watch some YouTube videos to get some insight.

How much does a rainwater storage tank cost?

We can’t say exactly and that’s because different manufacturers price their products differently.

The good news is, you can get a tank for your budget.