Understanding Rainwater Harvesting


In Australia and New Zealand, we understand how precious fresh water is to our land, livelihood, and lives in general. With many of our rivers and water catchments threatened by drought and the ongoing stress of our own withdrawal of water, a major way you can make your home more sustainable is to harvest rainwater

A common misconception about rainwater collection is that you just need a big tank on your property, a few pipes and some rain and you’re all set. However, this type of method has some limitations, such as water volume and quality for purpose. A Rainwater Harvesting system, on the other hand, is properly designed to give you plenty of clean rainwater to use in and around your property.

Transitioning to harvesting rainwater can be a little intimidating. You might have questions like; What equipment is needed? How will the recycled water perform? How much is this going to cost? Well, this article is designed to make it easy to understand how to begin harvesting rainwater at home as well as recommend some Jet Transfer Pumps to get you started.

Benefits of Harvesting Rainwater 

Using rainwater offers several benefits. Doing so can reduce your water bills, lower your ecological footprint, as well as provide an alternative water supply during water restrictions allowing for you to maintain a green, healthy garden. Reducing your reliance on mains water supply can in turn help to:

  • reduce the need for new dams or desalination plants
  • protect environmental flows in rivers
  • reduce costs of operating infrastructure.

By collecting rainwater from your roof, you can use this precious resource to water your garden, when washing your clothes and to flush your toilet. By capturing and using the rain that falls on your house, saving it from going down a stormwater drain, most Australian households have the potential to save more than 45,000L each year, not to mention hundreads of dollars!

Opportunities for rainwater collection and use will vary depending on your location. Typically, urban households will have a connection to a water supply but can significantly lower mains water usage by installing a rainwater harvesting system.
On the other hand, the majority of rural households have to source all their water on their property, and rainwater is often the better-quality option for household supply over river, bore or dam water.

What Can Rainwater be Used For?

Rainwater collected from a well-designed, well-maintained system can be suitable for all domestic uses. The more uses, the greater the saving! Keep in mind that the amount of water used for drinking and cooking is relatively small, and that state and territory health departments recommend using the public reticulated water supply for drinking and cooking because it is filtered, disinfected and, generally, fluoridated. For more information, consult your state or territory health department. 

Different end uses each require a different rainwater quality.

Rainwater Quality Requirements for Household Water Uses:

End use

Required quality

Clear Odourless Low in dissolved solids

No human pathogens, toxins or heavy metals

Garden/Lawn irrigation   
Toilet flushing
Clothes washing
Showering/Bathing
Drinking

  

Here are some other ideas for using rainwater around your home: 

  • Water your garden and lawn
  • Use in sprinkler or irrigation systems
  • Wash your pets
  • Wash your cars
  • Refill ponds or water fountains
  • Top up your pool water
  • Wash outdoor surfaces like driveways and paths
  • Wash windows (from outside)

How Does Rainwater Harvesting Work?

To understand how a simple rainwater harvesting system works, let’s look at the Waterboy Wizard system from Bromic.

Here is how it works:

Waterboy Wizard Diagram

  • Rainwater is collected in a rainwater tank.
  • This then passes trough a filter and into the Jet Transfer Pump.
  • The pump uses a controller (in this instance a water changeover controller) to control the flow of water into the dwelling.
  • Rainwater is then distributed to the required points including toilet, laundry and garden taps.

This is the fundamental way that many rainwater harvesting systems will work. There are submersible pump options, which we cover below.

What You Need to Get Started

To start harvesting rainwater at your property you will need the following:

  • roof and gutters
  • collection system, including leaf-shedding rain-heads and first flush diverters
  • water tank
  • supply system, such as pump, controller and filters.

We’ll cover off the supply system in more detail below and include some recommendations on product solutions for these. 

Setting up a Water Supply System

Pump

Selecting the pump for your needs is important. A suitable pressure pump will deliver water at the same or close to the pressure of mains water. Rainwater pumps are either submersible or free-standing. 

A submersible pump can be fitted in the rainwater tank, saving space and emits much less pump noise. For example, the Bromic Waterboy Clean & Dirty Water Submersible Pump

A free-standing pump is often the more affordable option and will be available in a wider range of pumping capacities. However, this type of pump requires a weatherproof housing or a protected spot near to the tank, as well as an enclosure to help limit pump noise. The Bromic Waterboy Jet Pump & Controller Kits are a good option here.

Pump Controllers 

A rainwater pump pressure controller is used to switch the pump system on and off as required in response to the water flow. The controller is usually mounted on the pump for outdoor uses. 

For whole-of-house rainwater supplies, a variable speed pump delivers a more even pressure at the expense of energy efficiency.

Some controllers are designed to switch the supply from rainwater to mains water when the rainwater runs out. This type of controller is generally used for supply to toilets, washing machines and other internal uses where a mains water supply is also available. Something like the Waterboy Wizard water changeover controller is suitable for this.

The Bromic Waterboy All-in-One Jet Pump Kits are complete plug and play pump kits, housed in a weatherproof case and available in a variety of pumping capacities. This type of all in one option will save you on the cost of purchasing the various components individually.

Making Rainwater Harvesting Easy

Now that you understand the benefits of collecting rainwater for use on your property, as well as the basics of how to get started, we hope you will consider a Bromic WaterboyTM pump for your needs.