What’s so bad about “unplanned” recycling?

Water recycling proponents often like to remind the sceptics that all water is eventually recycled. What goes around, comes around. In many instances, the cycle from drinking-water to sewage and back again can be very short. Throughout the world, the vast majority of such situations tend to be classified as “unplanned” potable recycling. Strangely, there is an apparent perception that unplanned potable recycling is generally accepted to be “bad practice”.

I disagree on two grounds. First, I think it is naïve to assume that most such situations are truly “unplanned”, -I suspect “unacknowledged” might be a more accurate term. But more importantly, the suggestion that this is “bad practice” needs to be considered in respect of the alternative.

There is probably not a river in the world that is at least 100 km long and does not have an upstream wastewater discharge and a downstream potable extraction. That is simply the way we live and it is the only way most cities on the planet can survive.

If cities from Minneapolis to Memphis did not return at least some of the water they extract from the Mississippi, there certainly would not be sufficient water to sustain cities from Memphis to New Orleans.

Some important rivers in Europe can flow at around 70% treated effluent during dry weather periods (and, of course, less during wet weather). Examples include the Thames (London’s major water source) and the Spree (Berlin’s major source). If Spanish cities did not return effluent to rivers after use, most of southern Portugal would surely be uninhabitable.

Water belongs to all of us to share and it is our responsibility to keep the world’s rivers flowing as the principal means of distribution. Use it wisely and put what you don’t need back, I say. This is especially important for inland towns and cities.

Cities like Toowoomba and Goulburn have an incentive to grow and clearly water is a necessary factor for growth. “Planned” water recycling offers opportunities for these cities to supplement existing supplies. However, we must remember that all water used for “planned” water recycling is no longer available for “unplanned” water recycling. This is an important trade-off that we must keep a close eye on.

However, the situation is different for coastal cities. Those such as Sydney, Brisbane, Melbourne and Perth discharge most of their used water directly into the ocean, cancelling any opportunity for recycling. These are the cities which have an obligation to implement sustainable water recycling schemes to make sure that they squeeze every opportunity from every valuable drop.

Most major Australian cities are at the bottom of their water catchments, with few significant populations upstream. Thus, on world-standards we are extremely poor “unplanned” water recyclers. We waste our most valuable resource by using it just once and then dumping it straight into the ocean. Our major cities, therefore must instead become world-leaders of “planned” water recycling. This is the only way that we can hope to live in a vaguely water-sustainable way.

Water recycling promises significant benefits for Toowoomba and Goulburn, but is absolutely essential for Sydney, Brisbane, Perth and Melbourne.

Feel free to click ‘comments’ below and tell me I’m a goose.