The Next Big Thing

I am confident now that the Next Big Thing in water in Australia will be urban stormwater harvesting for potable water supply.

 Why do I think this?

We recently heard here that our population is forecast to almost double in the next 40 years. Australia’s most densely populated south east corner has already experienced dramatic falls in average rainfall, and this is expected to worsen with climate change. Perth has already experienced this .

Meeting the water demands of population growth with declining rainfall will require every water supply and demand management option available.

Desalination will of course remain a growth area in spite of its challenges, but the big desal boom is already well underway and the market is already highly competitive. Potable  Reuse faces such high levels of societal pushback that it is politically very tricky.

As we have seen in Perth, conventional catchments experience dramatic falls in yield under climate-change conditions. Because of increased evapotranspiration and drying soils, the reduction in run-off far exceeds the fall in rainfall. Much less water gets to dams. Also our dams tend to be 100kms or so inland, and those catchments are very vulnerable to geographical shifts in rainfall patterns.

Our major cities however are all immediately next to the ocean, and get reliable rainfall. Urban impermeable surfaces are not effected by the evapotranspiration and dry soils effects, so urban water harvesting is a climate-change resilient option for water supply.

For the past 10 years or so, capacity to deliver stormwater harvesting solutions has been increasing, and Australia’s first potable stormwater harvesting scheme was commissioned last year in Orange, NSW, last year.

Delivering urban stormwater harvesting solutions requires water providers to go far outside their traditional scope. The only way to make it cheap and effective is to build your urban area around water sensitive urban design principles. This means that everyone has to get involved, from the urban planning phase onward.

If you are going to be involved in the Next Big Thing, how will you respond to the challenge of stormwater harvesting and WSUD?