As more people seek independence from municipal utilities, pursue sustainable living, or prepare for emergencies, rainwater harvesting is becoming one of the most accessible ways to improve water security. When combined with a reliable filtration system, such as a Berkey, collected rainwater can be safely enjoyed as drinking water.

It’s also worth noting that rainwater harvesting is now one of the most popular rural water collection methods.

This guide explains:

• What is rainwater harvesting
• What can collected rainwater be used for
• Is it safe to drink rainwater
• How to collect rainwater (3 methods of harvesting)
• What are the components of a complete rainwater harvesting system
• What should you consider before installing a rainwater collection system
• How to filter rainwater for safe drinking
  • …And why it pays to use Berkey water filters for this important task

Now, let’s start from the beginning!

What Is Rainwater Harvesting?

Rainwater harvesting is the practice of collecting and storing rainwater that falls on rooftops or other catchment areas, instead of letting it wash away as runoff.

While the concept is ancient, it has gained new relevance today as communities look for sustainable, affordable, and resilient water solutions. By capturing rainwater, households and businesses can reduce their dependence on municipal supplies and take pressure off aging infrastructure.

But that’s just the tip of the iceberg when it comes to the benefits of rainwater. So what other advantages does this method offer?

What Are the Benefits of Rainwater Harvesting?

From an environmental standpoint, rainwater harvesting reduces the strain on stormwater systems and minimizes runoff that can carry pollutants into rivers and lakes. It can also help conserve groundwater by reducing demand on local freshwater supplies.

Financially, it helps cut monthly water bills, especially when used for applications such as irrigation, where high water use drives up costs.

As rainwater is free of chlorine and other chemicals commonly found in treated water, it is gentler on plants and soils, as well as your skin and hair.

And let’s not forget that having your own independent water supply on site supports self-sufficiency and can provide a reliable backup supply during emergencies or disruptions.

In short, harvesting rainwater isn’t just a way to conserve resources; it’s a simple, effective step toward sustainable living.

What Can Collected Rainwater Be Used For?

Harvested rainwater can be utilized for a wide range of outdoor and indoor applications, and with the right treatment, it can even serve as a source of potable water. Some common uses of rainwater include:

• Outdoor uses
  • Irrigating gardens and lawns
  • Washing cars and equipment
  • Refilling ponds, fountains, and swimming pools
  • Washing pets
• Indoor non-potable uses
  • Flushing toilets
  • Running laundry
  • Bathing and showering
  • General cleaning
• Indoor potable uses (with filtration)
  • Drinking
  • Cooking

Is It Safe to Drink Rainwater?

While rainwater generally contains fewer contaminants than other sources of water, it is not necessarily safe to drink directly from your tank without treating it first.

Rainwater picks up dust, pollen, bird droppings, and other contaminants as it travels across surfaces, and these pollutants will flow into the storage tank along with the water.

But with proper collection methods and reliable filtration, it can be made just as safe, if not safer, than treated municipal water.

How to Collect Rainwater?

There are three common methods of harvesting rainwater:

1. Rain barrels – Plastic rain barrels are readily available, affordable, and beginner-friendly. They are attached directly to downspouts, making them easy to install. Rain barrels are best suited for gardens and small-scale use.
2. Dry system – These systems consist of a larger storage tank located next to the house with downspouts directed into it. While these tanks can store more water than rain barrels, they are quite bulky, but offer a great option for homeowners with more space and a higher demand.
3. Wet system – These systems consist of a network of underground pipes that channel rainwater collected from multiple downspouts into a tank located away from the house. While wet systems are more complex, they are efficient for larger properties.

Here’s a clear side-by-side comparison of the three rainwater harvesting methods based on cost, ease, and efficiency:

Method	Cost	Ease of Installation & Use	Efficiency / Best Use
Rain barrels	Lowest cost – inexpensive and widely available	Very DIY-friendly; quick to attach to a downspout; minimal maintenance	Limited capacity; ideal for gardens and small-scale use
Dry system	Moderate – higher than barrels but less than wet systems	Fairly easy if space allows; bulky tank; may be installed by homeowner	Larger storage capacity; good for households with moderate water needs
Wet system	Highest – requires underground piping, excavation, and a large tank	Complex; usually requires professional installation and regular maintenance	Most efficient; captures water from multiple downspouts; ideal for large properties

Components of a Complete Rainwater Harvesting System

A rainwater harvesting system consists of the following components:

• Catchment surface: This is typically a roof, but decks and other surfaces can also be used as a catchment that serves as a primary collection surface.
• Diversion system: Consists of gutters and downspouts that channel the rainwater from your collection surface to your storage system.
• Pre-filtration: Tools like gutter guards, rain heads, and first-flush diverters keep out leaves and other debris.
• Storage system: Options range from plastic rainwater barrels to above-ground storage tanks or underground cisterns that store the collected water for you to use when you need it in the future. The optimal size of your storage system will depend on local rainfall and usage.
• Distribution system: This can consist of a water pump (if your system is not gravity-fed and water needs to be pumped) as well as the water pipe network that distributes the stored water to where you plan on using it (for example, your home, garden, swimming pool, etc.).
• Insect & debris protection: Screens and covers to keep insects and dust out and prevent contamination of your water supply.
• Treatment system: the system you use to filter or treat the water to render it suitable for the purpose you intend to use it for.
• Optional add-ons: Level indicators, auto-fill systems with float shut-off valves that improve convenience.

What Should You Consider Before Installing a Rainwater Collection System?

Rainwater harvesting can be a smart and sustainable way to supplement your water supply, but before setting up a system, it’s important to think through a few key factors. The right approach depends not just on your budget and property, but also on your local environment and regulations.

Carefully considering the following points will help ensure your system is efficient, legal, and easy to maintain over the long term.

• Tank location – One of the first decisions is where to place your storage tank. Above-ground tanks are easier to install, inspect, and maintain, but they take up visible space and may impact your property’s aesthetics. Below-ground tanks, on the other hand, keep things out of sight and can store more water, but they are more expensive to install and harder to access for maintenance. Proximity to your home also matters – tanks located closer to downspouts reduce piping costs and make the system more efficient.
• Climate and rainfall frequency – Your local climate directly influences how much storage capacity you’ll need. If you live in a region with frequent rainfall, a smaller tank may be enough since it will refill regularly. In areas with long dry seasons, however, you’ll need a larger tank to store enough water to carry you through the dry spells. Reviewing local rainfall patterns helps ensure you don’t overspend on storage or underestimate your needs.
• Local regulations – Rainwater harvesting is not universally regulated the same way. Some regions actively encourage collection with tax breaks or rebates, while others have restrictions due to concerns over water rights or downstream ecosystems. Before investing in a system, check your state, provincial, or municipal rules to ensure compliance. Doing so not only avoids legal headaches but may also reveal opportunities to access incentives.
• Maintenance and upkeep – Like any water system, rainwater harvesting requires ongoing care to remain effective. Gutters and downspouts should be cleared of leaves and debris, filters should be cleaned regularly, and storage tanks need periodic inspection to prevent algae growth or mosquito breeding. Building a maintenance routine ensures that your collected water remains safe and that your system continues to perform reliably for years to come.

How to Filter Rainwater for Safe Drinking

Even with clean collection practices, rainwater still needs to be filtered before drinking. Contaminants such as bacteria, viruses, pesticides, or heavy metals from roofing materials can get washed off with rainwater and enter your water supply, posing a health risk if ingested.

Common rainwater filtration methods include:

• Mechanical filtration – removes particles and debris.
• Chemical treatment – neutralizes harmful microbes.
• UV systems – kill bacteria and viruses.
• Comprehensive filtration – in the case of advanced systems, eliminates common drinking contaminants.

And since we’re on the topic of advanced systems, let’s mention a solution that can make rainwater completely safe and suitable for drinking and cooking.

Filtering Rainwater with a Berkey Water Filter

Berkey water filters transform collected rainwater into safe drinking water without electricity, plumbing, or pressure. Their gravity-fed system removes over 200 contaminants, including PFAS, heavy metals, VOCs, and pesticides.

Because rainwater often carries pathogens and rooftop runoff pollutants, reliable filtration is essential. Berkey systems are portable, powerful, and proven for both daily use and full off-grid setups. Learn more in this guide to off-grid water systems.

Start Harvesting Rainwater to Gain Your Water Independence

Rainwater harvesting is one of the easiest and most rewarding steps toward water independence. Even a small barrel setup can save money, reduce your environmental impact, and provide resilience in times of need.

And if your goal is to make rainwater safe for drinking, a Berkey water filter systems are the perfect complement to your rainwater harvesting system – trusted, portable, and powerful enough to turn the rainwater you have collected into safe drinking water for your household.

Explore our Berkey filter systems →

FAQ

What is rainwater harvesting?
The practice of collecting and storing rain for later use.

Is rainwater harvesting a good idea?
Yes, it saves money, supports sustainability, and improves resilience.

What are the benefits of rainwater harvesting?
Lower water bills, reduced environmental impact, and increased independence.

How to make rainwater harvesting safe?
Use clean collection methods and filter the water with a reliable filtration system, such as a Berkey.

What is the best way to harvest rainwater?
It depends on your needs: barrels are good for small-scale use, while tanks and wet systems are better for larger properties and those with a higher water demand.

How to filter rainwater?
Use a rainwater filtration system for drinking water – Berkey filters are one of the most effective tools for filtering drinking water as they remove over 200 contaminants, PFAS, heavy metals, and harmful chemicals.

How to collect rainwater for drinking?
Install a rainwater harvesting system, then run collected water through a filter to remove any potential contaminants.

How to store rainwater for drinking?
Store rain in clean food-grade tanks or barrels, keep debris out, and always filter before drinking.

How to filter rainwater for drinking at home?
A Berkey water filter offers a simple, powerful way to ensure collected rainwater is safe to drink.