How Long Can You Keep Rainwater? A Definitive Guide

How Long Can You Keep Rainwater? Read on to Learn More

Rainwater harvesting has become an increasingly popular and sustainable practice and is an important part of your journey towards self-sufficiency and being prepared for an emergency. In this article, I’m going to answer the question how long can you keep rainwater?

Collecting and storing rainwater can significantly reduce dependence on municipal water sources, help you save money on utility bills, and can be used for plants, cleaning, bathing or even drinking.

But, it’s vital that if you are going to use rainwater harvesting as a way to conserve resources, you store and maintain it properly.

Rainwater can be kept indefinitely if it is stored in tightly sealed tanks or barrels. Just like any other water source, rainwater can become stagnant or contaminated over time – especially if exposed to sunlight.

In this article, I’ll explore the question of how long you can keep rainwater – and offer tips on how to increase its longevity.

I’ll also look at the best containers in which to store rainwater and ways to store rainwater for those living in urban areas who don’t have room to keep large storage facilities.

Table of Contents: How long can you Keep Rainwater?

How Long can you Keep Rainwater? Factors Affecting Rainwater Shelf Life

Rainwater has many benefits. Not only is it considered to be one of the best sources of water for plants due to its purity and lack of added chemicals such as chlorine and fluoride, but rainwater also has a pH level that is neutral or slightly acidic, which makes it ideal to keep your plants nourished.

There are many different opinions on how long you can keep and store rainwater. Some experts say for just a week, others say much longer, potentially even years! The reality is it depends. If you go about storing it properly, you can store it for as long as you wish.

Before we delve into the details of the best containers to keep your rainwater, let’s have a quick look at some of the things that can make your collected rainwater go bad. Here are the main factors:

1. The temperature and sunlight can affect your rainwater. If it’s too hot or there’s too much sun, cracks can occur in rainwater storage barrels and unpleasant organisms can grow on the surface of the water.
2. Things like bird faeces, air pollution, and stuff from your roof can get into the water, which can lead to bacteria that’s bad for you.
3. The container you use to store the water makes a massive difference. If your container isn’t covered or sealed properly, bugs and microorganisms can get in.
4. Be careful where you collect your rainwater from! Some surfaces and roofs can be contaminated with pollutants or other contaminants, so your water may not be safe – even if it’s stored properly. This is why it’s so important to collect the rainwater from a clean surface.
5. To keep your rainwater fresh, you’ll need to take care of the container. If you don’t clean it regularly, dirt and gunk can build up and create a breeding ground for bacteria.

How Long can you Keep Rainwater: What are the Best Containers to Store Rainwater?

When deciding how and when to store rainwater, a key thing to consider is the containers in which you will store your rainwater.

As mentioned above, you will need a clean container that has not been used for other purposes. Your container will also need to be sealed properly, because sealing is the key to maximum storage of rainwater.

Rain Barrels

If you are living in a normal, suburban house – or even an urban area in an apartment, barrels can be a good option to collect rainwater.

There are several reasons why barrels are a great choice for rainwater storage:

• They are relatively easy to obtain and can be purchased from many hardware stores or online retailers.
• They are practical and durable.
• They are inexpensive and can withstand the elements.
• They are also available in different sizes, so you can choose one that suits your needs – for example, for a small, outdoor city space like a balcony or a backyard.

Rainwater Tanks

The reality is that if you wish to store rainwater indefinitely, tanks are a better option. Unfortunately for many of us this simply isn’t possible when living in a city where it isn’t always simple to collect rainwater.

But on the off-chance you do have some room for a tank, here are some of the benefits of concrete tanks:

• Concrete tanks can store harvested rainwater safely for long periods with no seepage whether built above or underground.
• They act as natural insulators and keep water cool for extended periods.
• The durability of tanks means that sunlight cannot affect the rainwater in concrete tanks, so they are free from algae formation.
• They can withstand extreme weather conditions, so depending on your climate, concrete may be the best option.
• They reduce the acidity of naturally acidic rainwater, making the water safe for domestic purposes.

There are also some disadvantages to storing rainwater in concrete tanks. They tend to be more expensive and can be a hassle to install. They are also heavy as well as porous – which means they can easily develop cracks and leaks.

Other tanks you can use include:

• Polyethylene tanks – These tanks are very versatile and come in various sizes, shapes, colours and connection options. Not only are they cost-effective, but they are also non-porous and easy to install.
• Fibreglass tanks – These tanks are lightweight, durable, resistant to rust, corrosion, and UV damage, and non-porous, making them suitable for storing rainwater. The downside is they can be more expensive than other types of tanks, and they may be prone to cracking if not installed properly or exposed to extreme temperatures.
• Metal tanks – There are several advantages to metal tanks, including the availability of many sizes and capacities and their ability to withstand harsh conditions, including fire. The material is also UV resistant. But, you have to keep a stern eye on your tank to ensure it doesn’t rust – so make sure you keep it clean.

As mentioned above, the problem with tanks is that they are not very realistic for a lot of people with only limited space to use for rainwater harvesting and storing. This is why rain barrels are a more realistic option in city areas.

Another option to store rainwater is a cistern which can store water for a significant amount of time.

How Long can you Keep Rainwater: What Material is Best for Rain Barrels?

For most people, plastic rain barrels will be the natural option because they are lightweight, durable, easy to transport, inexpensive and accessible. They are typically made of polyethylene plastic, because this type of plastic has high resistance against corrosion.

Some people have concerns about leakage of endocrine-disruptors and other toxins into their rainwater – but this polyethylene plastic is FDA-approved for food contact so is generally considered safe.

But, if you don’t want to use polyethylene or other plastics as materials for your rain barrels, you could opt for stainless steel. These are recommended because they are sturdy, and, let’s face it, prettier!

In fact, they can even be painted to match your home’s exterior. But they are not as affordable and much heavier, so you will want to bear this in mind when making your choice.

And, if you’re feeling adventurous you can even make your own barrel – as explained in the video below!

How Long can you Keep Rainwater: Where do you Store Rainwater?

Storing rainwater in a dark place, such as a garage or basement, can help to maintain the purity and quality of the water by inhibiting algae growth and regulating the water temperature.

This can also protect the barrel from UV damage which can cause cracks. So, if possible, choose a suitable storage location that is cool, dark, and well-ventilated to keep your rainwater in optimal condition.

How Long Can You Keep Rainwater For Plants?

With appropriate treatment and precautions, rainwater can be stored for plants indefinitely.

While rainwater is naturally suitable for plants, it’s important to implement proper storage practices. In the event that rainwater develops algae or becomes stagnant, its advisable not to use it for your plants.

Such contaminated water may hinder their growth, promote diseases, or even lead to their demise.

How Long can you Keep Rainwater: Consider the Age of Rainwater

When you’re keeping rainwater for your plants, remember that age matters, as much as all of us wish it didn’t!

As time passes, the water naturally can become stale, causing anaerobic bacteria and other tiny critters to take over. This is especially true if you’re not moving or mixing the water regularly.

To avoid this, try shaking up the container or use a pump to circulate the water. Always use the older rainwater first, topping up with fresh rainwater as necessary to keep your plants happy and healthy.

How Long can you Keep Rainwater: How Much Rainwater can you Store in Cities?

For those of you who have acres of land, storing rainwater isn’t an issue because there’s plenty of space for as many barrels as you need.

But for those of you living in urban areas, storing rainwater in smaller spaces such as balconies, city gardens, and backyards can be more difficult.

But, the good news is that it’s still well worth collecting rainwater, because although the amount of rainwater that can be stored is limited, this can still be a significant source of water for plants and for general use in times of need.

Use Smaller Barrels

The key to maximising the amount of water that can be collected is to make the most of the available space by using smaller barrels. Some people even use buckets!

By strategically placing these containers in areas that receive the most rainfall and linking them together, you can create a system that collects and stores rainwater efficiently.

Pollutants

One key problem affecting urban areas can be pollutants. Rainwater can contain pollutants from the air and surrounding environment. To ensure that the water is safe for use, it’s recommended to filter the water before using it.

This can be done using simple filtration methods such as using a clean cloth or coffee filter to strain the water. You can also boil the water or use water purification tablets which can also help to make the water safe for consumption.

By taking these precautions and making the most of the available space, you can create a reliable source of water for emergencies and everyday use.

How Long Can You Keep Rainwater: Final Thoughts

I hope that this article has taught you more about how long you can keep rainwater. The truth is, rainwater can be kept for plants indefinitely if it is stored properly.

But, it is important to ensure the quality of the rainwater, the storage conditions, and the age of the water to ensure that it is still suitable for plants.

By following these guidelines, you can make the most of this valuable resource and provide your plants with the purest and most natural water possible.