Rainwater Harvesting And Collection: How To Get Started | Build a Stash

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Key Takeaways

  • Rainwater collection can be as simple as setting up a rain barrel.
  • Rooftop or surface ground collection are the two types of rainwater harvesting.
  • No rainwater should be consumed by humans without filtration systems.

You’ve decided to make your garden self-sufficient, part of that process begins with a water source, so you need to know how to harvest and collect rainwater.

A rainwater harvesting system can make your home more eco-friendly and self-sufficient with an additional water supply. Simple rain collection systems use 40 - 100 gallon barrels, while larger systems use cisterns with filtration systems to capture surface water for human water consumption.

Harvesting rainwater is becoming a much more popular resource for self-sustaining homeowners nationwide. With the scarcity of this precious resource occurring all around the planet, many families are collecting and storing rainwater that falls around their homes. While it requires some planning and a little equipment, a home rainwater harvesting system is an excellent way to lower bills and improve the quality of a home. But how do you get started? Is collecting rainwater safe to use as drinking water? Do you need a massive storage tank to collect and filtrate the water running off your roof or just set out a barrel and let the water accumulate? This article will help answer some of the questions about how to get started harvesting and collecting rainwater.

Table of contents


What is Rainwater Harvesting?

Rainwater harvesting is collecting the run-off of a roof or structure and channeling it into a collection device (barrel or cistern) for use later on. Rainwater harvesting can vary from a simple barrel system designed to help or a more elaborate collection in a cistern with a dedicated filtration system. Whether for a homeowner trying to keep his vegetables healthy, or a green building being built with a rainwater storage tank to channel stormwater runoff. These harvesting systems can collect and use rainwater for indoor plumbing applications, like toilet facilities, or industrial applications. With the need to conserve water becoming more prevalent every day, it is easy to see how collecting rain is more important than ever.

What Are the Advantages Of Rainwater Harvesting?

There are several advantages to installing a rainwater collection system.

  • Lower dependence on municipal water systems
  • Lower water bills
  • Better for the environment
  • Steady source of water for gardening, vegetables, or personal plantings
  • Use for Livestock Consumption
  • Human Consumption (filtration system or rolling boil for at least one minute to remove pathogens harmful to ingest).

Why Should You Not Use Rainwater for Human Consumption?

Rainwater can contain toxins, residual debris, mold, bird feces, and nasty pathogens like E-coli and other pesticides. Acid rain often occurs in areas of the country where the evaporation of residual water contains industrial chemicals that get sent down during storms and end up in groundwater supplies. While municipalities often allow rainwater collection systems to water the lawn or gardens, they may only allow use inside the home with a filtration system. (You will likely have to have an inspector certify that your system is safe should you choose to use rainwater harvesting for anything other than watering your lawn).

How Do You Get Started With Rainwater Harvesting?

Several things are essential when developing a rain harvesting operation.

Decide What Purpose The Water Will Have For Your Home

Before you begin, it is essential to have a plan for the water you intend to collect. There is a big difference between collecting water for a garden and some vegetables and using the water to cook, clean and bathe. The more extensive plans you have for the rainwater, the more involved the project will become and the greater the expense.

There are three different uses for collected rainwater.

  • Simple collection for gardening/plant watering
  • Domestic Home Use (non-potable)
  • Domestic Home Use (human consumption - cooking, drinking, bathing, hand-washing).

Determine Cost With A Plan

With a detailed plan, you will likely have a much easier time figuring out what equipment you need to complete the task. Domestic uses for human consumption should never be installed without an adequate filtration system. (Many city municipalities have strict codes for what kinds of filters and the water quality must be produced and will require testing and inspection).

There are a couple of ways to catch rainwater for home use. An extensive rooftop rainwater-catching system can cost thousands of dollars. Most collect the run-off from roofs into cisterns that are pumped into the house through a usable filtration system.

Rural homes with well water or not connected to municipal water utilities can bury a cistern near a collection pond to collect surface run-off water. Generally, the rainwater that collects on the ground runs from the surface into a collection area (like a pond) and into a buried nearby cistern.

The groundwater can then be pumped through a filtration system or a series of filters (usually part of the pumping station) before being directed into the home. Because rain and surface groundwater can always contain toxic chemicals or pathogens harmful to humans, there needs to be an adequate ability to make the water usable for human consumption. (Remember that you need to ensure that local building codes are met).

The cost of landscaping a collection pool and burying a cistern can run up to $20,000 for the heavy equipment and labor that will need to be involved.

What Is The Difference Between Grey Water and Rainwater Collection?

There is a distinct difference between the water that is collected from rainwater harvesting systems and the water you have from bathing, washing clothes, or washing fruits and vegetables. The water considered greywater is relatively clean used water from sinks and showers, but it is unsuitable for human internal consumption.

While some complicated systems recycle grey water, it is never good to use it to water gardens or vegetables that will later be consumed unless it is run through a filtration system. Many new home construction sites employ these “grey-water” systems to conserve the demand on municipal systems and aid in the local conservation of water that may already be in scarce supply.

Rainwater collection can be used for grey-water purposes, and many building designers worldwide are exploring systems to do so.

What If I Want To Install A Simple Rain Barrel System?

If you plan on using the water for watering your garden, then you can set out a barrel under the downspout of your gutter and have the run-off water from your roof run down into it. Rain barrels are sold at almost any hardware or big-box store, and their installation is easy for the average homeowner. The whole system can be implemented for less than $100.

The following are some steps that you want to employ when creating this kind of system.

Have Screens Installed On Your Guttering

Because rainwater comes off of your roof in torrents at times, it pushes debris, dirt, mud, and leaves into your gutters. If you have ever had to clean out your home’s guttering, you know that you don’t want to have that stuff in the water you are dipping into for your vegetables.

Choose Your Containment Barrel

Most hardware stores sell rainwater collection barrels, but you should look out for a couple of things when purchasing one.

  • The barrel must be large enough not to be knocked over by pets or children and large enough to hold the water.
  • The color should be opaque to prevent any kind of algae growth.
  • Be covered to prevent debris or kids from messing with it.

Remove A Section Of The Downspout

You want the downspout to funnel the run-off water into the barrel. You may have to cut a downspout section to allow the rain collection instrument to fit. You want to have a barrel that is large enough to accommodate the amount of rain your area receives. (The more average rainfall reaches your region, the larger barrel you will likely need).

Put Your Rain Barrel On Blocks

Your rain barrel should be off the ground. Rainwater is affected by gravity just like anything else. Rather than reaching all the way to the bottom to scoop out the few drops of precious water, stack the barrel up, and insert a plug in the base. (Many rain barrels come with stoppers at the bottom of the barrel to allow convenient water retrieval). A barrel that is elevated makes attaching the hose much more manageable.

Consider the Location of the Barrel Carefully

Never place the rain barrel near a structure or stairs where animals or children can climb onto the top. You want the barrel closed at the top with a lid (you can cut a hole in it to fit the downspout).

Install An Overflow Valve Near the Top

If there is no overflow valve on the barrel, you need to install one. An overflow valve should stay open and is designed to keep the water level in the barrel from overflowing and creating a mess. (Most gardeners attach a rubber hose from the open valve to a nearby flower bed to use the overflow that might occur).