Rainwater Harvesting: How to Collect Rainwater at Home

Rainwater Harvesting: How to Collect Rainwater at Home

Table of Contents
Table of Contents

Collecting rainwater at home for various uses is a fantastic way to save money and conserve water. Depending on how much rainfall your area receives, you may be able to collect enough – or more than enough – rainwater for all your water needs.

Harvesting rainwater is an important step to becoming a self-sufficient homesteader or going off-grid. The water you collect can be used for farming, washing clothes, and cleaning. If you hope to use rainwater for drinking, you will have to filter the water first, and then it can be stored for up to 6 months.

In this article, we’re going to discuss the various ways you can safely collect rainwater, why you’d want to store rainwater, and how to use rainwater. To learn more, read below.

Rain barrel in tropics

What Is the Purpose of Collecting Rainwater?

Collecting and processing rainwater has a bunch of benefits:

  • Collecting and using rainwater can save you lots of money. Over 40% of household water consumption in the US goes to domestic irrigation. That’s a hefty expense that a simple rainwater collection system can make up for since irrigation water doesn’t need too much filtration. What’s more, you can use rainwater for most of your household’s domestic needs.
  • Collecting rainwater prevents erosion and flooding. You’ll have less stormwater to manage since a well setup rainwater collection system can collect roughly 80% of the annual water that falls on your property.
  • There’s less water contamination. A sound rainwater collection system makes use of filters to reduce the contaminants in your collected water. So, even if you’re using your rainwater for gardening only, you’ll still be reducing the water contamination.
  • Rainwater is an excellent source of soft water. If you’ve been experiencing issues with hard water, installing a rainwater collection system for your home can solve that problem.

Step-By-Step Guide on How to Collect Rainwater

Although there are many different ways to set up a rainwater collection system, the most basic setup will make use of a catchment area, a conveyance, and an area for storage. More advanced systems may make use of a water pump and a filtration device for pushing large amounts of potable water.

1) Catchment Area

The catchment area is the first point rainwater will make contact with in your collection system. A broad and flat surface that’s angled slightly downward will work best.

Corrugated Metal Roof

For the purposes of collecting rainwater at home, your roof will work well as the catchment area due to its large surface area and angle. However, do keep in mind, pre-painted, corrugated metal roofings are the only types of roofs that can make rainwater safe to drink. Other types of roofings may leach chemicals into your water, making it difficult to filter pollutants out.


If you don’t want to use your roof as the catchment area, a plastic or vinyl tarp will work just as well. You’d typically lay out the tarp on the soil where you’ve dug out a collection area. A pool of water will form here as the rain starts to fall.

Since you’d typically use collection tarps at ground level, you should place them at an area of higher elevation than your storage tank or storage container. This will allow gravity to help with moving the water.

2) Conveyance

As the rain begins to fall and starts to build up in your catchment area, you’ll need a conveyance system to transport the water to your collection site.

Metal Gutter

If your catchment area is your roof, the most practical form of conveyance for you would be your roof’s built-in rain gutter.

If your roof doesn’t have a built-in gutter, you can make one using semi-circular galvanized steel, aluminum, PVC, or copper. How wide your gutter should be will depend on the average amount of rainfall in your area. When in doubt, however, a wider gutter is usually better.

To ensure the gutter is clean and does not contaminate the rainwater, we suggest cleaning out the gutter every 3 to 6 months.

Note: You can use plastic gutters, however, since they have couplings to connect the different sections of the gutter, algae, pathogens, and debris, tend to gather around the couplings.

Downspout Drainage

Storing WaterAside from using a gutter, you can use a downspout as your form of conveyance. The downspout will carry rainwater from the roof to your collection area.

You can connect the gutter to the downspout, so more water flows to the downspout into your storage container.

3) Pre-Filtration

A simple filtering system can protect your rainwater from debris which can contaminate your water.

Mesh Screen

If you find that your rainwater collection system tends to be clogged by debris often, you can choose to install mesh screens to prevent this from happening. Simply line a mesh screen along the top opening of the gutter – or whatever conveyance system you’re using – to prevent debris from entering your conveyance channel.


Although mesh screens are great for stopping debris from entering your water collection system, it’s not uncommon for debris to build up and clog the downspout. When this happens, you’ll want to use a downspout diverter kit to allow the debris to continue falling through the downspout while the water is diverted into your storage area.

4) Storage

YoWater Barrel Collectionu’ll need a dedicated storage solution to gather and store your rainwater. A food-grade polyethylene plastic barrel is the safest and most common tool for collecting and storing rainwater. A rain barrel is specifically designed for rainwater collection, is durable enough for most environments, and holds about 50 gallons of water.

In addition to a rain barrel, water tanks and water butts are popular water storage locations.

Your storage needs will vary from that of other people. Luckily, you’ll find that rain barrels come in different shapes and sizes. It’ll be easy for you to find the right rain barrels for your purposes.

5) Water Pump

A water pump is used to transfer water throughout your home. Water pumps increase the water pressure to use in more applications. So, they give you more options when it comes to the ways in which you can use your rainwater supply.

The right water pump can significantly increase the flow rate in a rainwater collection system. This can make gardening, washing, cooking, and even bathing using rainwater more convenient.

Note that there are hundreds of types of water pumps out there. These pumps vary in terms of size and power; thus, it’s crucial that you choose the right pump for your situation in order to maintain a properly functioning water collection system.

Regardless of what type of water pump you choose to get, you should install the pump close to your storage rain barrel. This allows the pump to create enough pressure to direct your water supply in the right direction.

6) Post Filtration

Note that most rainwater collection systems are set up for outdoor use. But with a modified setup, you can use your collected rainwater for indoor uses like cooking, washing, bathing, and even drinking. You’ll want to install a proper in-house post-filtration system to remove harmful contaminants for these indoor applications.

When choosing a post-filtration system, keep in mind that filtration systems vary widely. For example, sediment filtration systems remove particles of debris. This type of filtration makes water ideal for bathing and cleaning. If you want to drink the water, though, you’ll need UV filters. The type of filtration system you should get depends on your needs.

Other Methods to Collect Rainwater

Let’s touch on an alternative method for collecting rain water.

A Plastic-Lined Pond

You may choose to collect rainwater by using a plastic-lined pond. This pond collects funneled water from your roof or property via pipes or gutters.

When setting up this pond, you can choose to dig your pond as deep as you’d like. Then, you can opt to cover your plastic lining with flat river rocks to make the pond more aesthetically pleasing. Not only does this pond collect rainwater for you, but it also serves as a proper flood-prevention system.

Is Rainwater Drinkable?

There’s nothing inherently dangerous about drinking rainwater. You’ll just need to make sure it’s clean enough for consumption. In fact, many communities across the globe depend on rainwater as their primary and only source of drinking water. With that said, however, not all rainwater is safe for drinking.

Water Barrel Set Up

There are many physical and environmental hazards that can quickly turn fresh and clean rainwater into a health hazard. Suppose you don’t process and handle your rainwater correctly. In that case, you may find that your rainwater contains parasites, viruses, and harmful bacteria that may cause diseases if you were to drink from the rainwater.

If you’re in a heavily polluted area or you’re in a place wherein heavy metals and the presence of animal feces is common; your rainwater may not be safe for you to drink, and may require you to test your collected rainwater; otherwise, your rainwater should be completely safe for drinking – provided you put it through the proper filtration systems.

How Long Can You Store Rainwater?

If you’re only using your stored rainwater for watering your plants or for cleaning purposes, you can store the water indefinitely. Of course, regardless of how you use it, the cleaner you keep the rainwater, the better. But for these simple purposes, they should last pretty long.

If you are using your collected rainwater as drinking water or for bathing purposes, you should not store them for longer than one week. If you keep your water for more than one week, it may cause you harm if you choose to drink it.

hand in rainwater

How Can I Use Rainwater?

A proper rainwater collection system can turn rainwater into a primary water source for all your water needs. You can use your rainwater for a wide range of uses, such as:

  • Watering your survival garden or flowers
  • Household Cleaning
  • Washing Clothes
  • Showering
  • Drinking Water
  • Composting
  • Water for Livestock and Pets
  • Flushing Toilets
  • Protecting Against Fire
  • Washing Vehicles

If you find yourself with extra water in your barrels, you may want to share it with your community as they may be in need. Sharing resources when times are good will help build friends and allies for when SHTF.

How to Prevent Rainwater from Stagnating?

When storing rainwater, preventing the water from stagnating is an important step. Stagnating water is a breeding ground for insects, algae, bacteria, and diseases, as well as emits a foul odor. To prevent rainwater from stagnating, we suggest you:

  1. Store rainwater in food-grade rain barrels: These types of containers are designed for water collection and are effective at keeping out sunlight.
  2. Apply a screen and lid to the container: This type of cover will prevent leaves, twigs, and other objects from contaminating the water.
  3. Keep your gutters and catchment area clean: Ths presents any contamination from debris going into your water.
  4. Use mosquito insecticide. Use a non-toxic agent to kill mosquitoes and larvae. Mosquito Dunk can be applied to the water, killing the mosquitos but still making it safe to use for watering plants and animals.
  5. Use the rainwater often. You should aim to empty the water barrel within one week so that insects and bacteria do not have time to breed.
  6. Clean the Rain barrels. Use vinegar to scrub the barrels to remove any contaminants. Using vinegar will make it safe to fill with water and give it to plants and animals.
Shelf Life of Rainwater

Final Thoughts

You don’t need to depend on a water company to provide you with water for your water-based needs. Instead, you can set up your own water system that makes use of collected and filtered rainwater. If you’re in an area that doesn’t see too much rainfall, you may opt to use your rainwater collection system as a supplement – rather than a replacement – for a traditional water system.

To learn more about food storage, homesteading, and living off-grid, check out the other detailed guides on our website.

Related Article: Extending the Shelf Life of Water for Long-Term StorageWa

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