Are you wondering if you can capture and reuse the water that falls on your home, rather than sending it to the stormwater drain?

Discover what rainwater harvesting, greywater and blackwater systems actually involve in a residential project.

Listen to the episode now.

Hello! This is Episode 412, and Way #12 of the 44 Ways to Create Your Sustainable Home series here on the podcast. We’re continuing through Section Three: Sustainable Services and Infrastructure.

In Episode 411, we looked at where household water goes, especially in indoor use, and how to reduce consumption through fixture selection and design decisions. 

In this episode, we’re looking at the other side of that equation: not just using less water, but capturing and reusing the water that falls on and around your home.

Way #12 is: Store and Reuse Water for Greater Water Saving.

Outdoor water use accounts for approximately 40% of total residential water consumption in Australia. That’s a larger proportion than any single indoor category, including showers. Even a household with highly efficient indoor fixtures is still potentially directing an enormous volume of treated drinking water onto the garden.

The core principle of rainwater harvesting is fairly straightforward. Rain falls on your roof. A first-flush diverter, fitted to the downpipe, discards the first volume of water from each rainfall event. This is the water that carries dust, debris, and whatever else has accumulated on the roof surface. The cleaner water that follows is directed into a storage tank. From the tank, a pump can deliver it to wherever it’s needed.

Your garden doesn’t need drinking-quality water. It needs water. 

And in most parts of Australia, water falls freely from the sky at various points throughout the year. The question is whether your home is designed to capture and use it, or to direct it straight into the stormwater system.

How a rainwater system is configured depends on what you intend to use the water for. 

For garden irrigation only, the system can be relatively simple. For toilet flushing and laundry use, the requirements increase slightly. For whole-of-home use including drinking water, filtration to potable standard and careful tank sizing become significant.

My own home is solely supplied by rainwater. Living on rainwater has shifted my approach to water use, my awareness of the weather, and my appreciation for how our water tastes.

We watch the weather a lot more closely. We monitor tank levels carefully, especially during dry periods. And we’ve learnt the difference, particularly in taste and feel, between rainwater and town water supply.

Greywater is another potential source of water reuse in a home. Greywater is the water from showers, baths, hand basins, and laundry. It doesn’t include toilet waste, which is referred to as blackwater. 

Greywater can be diverted and reused, most commonly for garden irrigation, without extensive treatment. In a household that generates a reasonable volume of shower and laundry water, this can supply a meaningful portion of garden irrigation needs.

Blackwater is rare in projects, but is certainly worth considering based on your location, project needs and local regulations. 

Blackwater treatment requirements are considerably more complex, and regulatory requirements are significantly higher. 

In this Episode, I cover:

• Why outdoor water use is the biggest single category of residential water consumption, and what that means for your project
• The basics of rainwater harvesting, including first-flush diverters, tank sizing, pumps and filtration
• How a rainwater system gets configured differently for garden-only use, toilet and laundry use, or whole-of-home potable use
• Above-ground versus underground tanks, and what to consider for your site, budget and aesthetic preferences
• My own experience of supplying our family of five entirely on rainwater for over a decade, including what I’d do differently if I had my time again
• What greywater systems involve, where they suit a residential project, and what regulatory approvals can look like
• Why blackwater systems sit in a more complex regulatory space
• Why bushfire zone requirements, septic systems and other site-specific factors really do matter

Plus a whole lot more.

LISTEN TO THE EPISODE NOW.

RESOURCES

Listen to the Joost Bakker podcast episodes on the Future Food System project:

• Episode 266 ‘Future Food System: the Zero Waste House, with Joost Bakker’ >>> https://undercoverarchitect.com/podcast-future-food-system-zero-waste-house-joost-bakker/
• Episode 267 ‘Building with Zero Waste: Greenhouse by Joost, with Joost Bakker’ >>> https://undercoverarchitect.com/podcast-building-with-zero-waste-greenhouse-by-joost/ 

WELS rating scheme (Australian Government water efficiency ratings) >>> https://www.waterrating.gov.au/ 

WaterSense (US EPA water efficiency program) >>> https://www.epa.gov/watersense 

Unified Water Label Association (Europe) >>> https://uwla.eu/ 

Michael Mobbs’ Sustainable House >>> https://www.sustainablehouse.com.au

’44 Ways to Create a Sustainable Home’ e-guide >>> https://undercoverarchitect.com/ways 

Access the support and guidance you need to be confident and empowered when renovating and building your family home inside my signature online program, HOME METHOD >>> https://undercoverarchitect.com/courses/the-home-method/