Water management in the city

Properties in the city are mains connected, so there’s no problem, right? Well, water tables are falling and we are becoming more and more dependent on desalination.

But isn’t there enough ocean? There might be enough water in the ocean, but desalination is very energy-intense. Even if we switch to 100% renewable energy, this requires huge infrastructure, which is dependent on fossil fuels and is easily disrupted. At the time of writing this blog post, about half of our drinking water in Perth comes from desalination and this portion is growing.

Luckily there are ways to save water and energy in a city home as well. Here’s what is happening in Martina’s house in the Northern suburbs of Perth.

Over the years, we have installed 5 water tanks with a total capacity of 10,000 l of water storage. In good rain years and if we are really careful with our water use, this can mean independence from mains water for up to six months of the year. In dry years and with three teenagers in the house, four months are more realistic, but that is still four months more than it was before. Because the tanks keep refilling in winter, we estimate we ‘save’ about 30,000 l of mains water each year this way.

We don’t have lawn, but the food gardens need a considerable amount of water. Ours could be more productive because we never quite irrigate enough. Some of our more productive areas are wicking beds or pots watered by ollas. Please read the article on Low-tech Ways to Water Plants if you haven’t heard of these techniques before.

Our chickens have their own small tanks made out of olive barrels catching from their coop roof. They never run out and are completely independent of mains water. Since rain water is healthier for them as well, that makes for happy chickens.

A bucket in the shower can catch water for next toilet flush. Speaking of toilets, we very much follow the principle of “If it’s yellow, let it mellow, if it’s brown, flush it down.” Flushing the toilet after every wee can use as much as one quarter of your indoor water use.

A basin in the kitchen sink catches water from rinsing produce and washing hands to use in planter pots outside.

While I promote a small bucket and a wash cloth as an alternative to constant showers, I have to admit that not enough of that is happening at our house (do I have to mention teenagers again?). But I don’t think we have to be perfect at this just yet. We just have to be aware and do our best.

We also have a commercial greywater system though, which diverts water from laundry and one bathroom onto parts of the garden. Greywater systems are fantastic because teenager showers produce relatively clean waste water all year round. There are rules around greywater to keep it safe, so make sure you educate yourself before you build or buy your own system.

The other side of using water responsibly in Perth in my opinion is producing and exporting as much energy as possible to the grid. The more energy we can feed into the grid, the less is produced burning coal. We won’t go back to not needing desalination plants in Perth, but we can try to reduce the pressure to build more by saving water, and produce clean(er) energy to make them as sustainable as possible. An oversized solar system and battery now ensure that we are not only exporting energy to the grid but rarely if ever import.

Saving water can be tackled from many different sides. Small and low-tech, like catching water in buckets and carrying it to your plants, as well as installing tanks or greywater systems with a bigger impact. It all counts and is important.

"Start where you are. Use what you have. Do what you can." Arthur Ashe