Rain – full of good things

It seems that rain is increasingly becoming a rare commodity where I live in Australia, as it is in other parts of the planet.

My home city is Adelaide, the capital city of South Australia: it’s a city of well over a million people that would not exist today if it depended on the water catchments in its immediate region.

Adelaide is the driest city on the world’s driest continent besides Antarctica (where precipitation is vital but hardly an immediate need).  The annual rainfall during most of the 12 years of this new century has been well below average.  Some years it’s been little more than 50% of the long-term annual average, which is already quite low.

After we moved to Adelaide in 1997, the annual rainfall was close to average for several years, and I found it reassuring that every year the shortfall of rain in one season was always made up by December 31… but no longer.  Like many places worldwide in recent years, the city started to break more records than ever before: the driest month ever, the driest season and year ever, the longest heatwave, the highest average temperature for a month, a season, or a year; one spring (normally part of the wet season) even became a record breaking dry time.  Most of the last ten or so years have now become the longest drought on record now.

And still there are climate change sceptics?  The severity of Australia’s recent, predicted and all-too-often traumatic climate change symptoms has moved almost everybody to accept (many only grudgingly) that the climate is in fact changing.  Lethal firestorms, more frequent cyclones and floods, depression in “the bush”, and record-breaking weather events: these happenings and their cause as man-made were modelled and predicted by scientists many years ago.  How sad that although we are now forced to respect the predictions as valid, so many still reject the science and causes that made up the predictions.

One recent summer Adelaide had the longest heatwave then on record in any Australian capital city, and this year we were in Perth when they set a record for the greatest number of heatwaves (eight in one summer)!  An Aussie heatwave has at least 3 consecutive days over 35 degrees.  In Adelaide we recently had a two weeks plus heatwave – in the first month of Autumn (Fall).

Adelaide’s annual evaporation rate has always far exceeded the rainfall, but Australia’s southern coast has a Mediterranean climate (hot dry summers and cool rainy winters) which allows the city’s mostly clay soils and the specially adapted native vegetation to hold enough water to last through the summer.

The coming of British and European settlers in the 1830s found the Adelaide summers a challenge, but hey, until the mid-20th century life was tough in all sorts of ways for almost everyone everywhere except for the most well-off.  Adelaide built dammed the very modest streams in the hills east of the city, but their potential was limited.  The post–World War 2 migration program and industrial expansion forced the city to build pipelines linking the River Murray to Adelaide (80 km away) and other cities and towns up to 400 km away.

Pipeline from the Murray River at Mannum to Adelaide

Continuing growth and climate change made these twin sources (catchments and river) insufficient and unreliable, to the extent that the State government drew up plans to deal with an emergency: building a weir across the Murray and warehousing drinking water.  Like every other Australian capital on the mainland it also built a wind turbine driven desalination plant, the cost of which should help drive down water wastage!

You can imagine how welcome rain is, especially in a situation like ours in Adelaide.  We’ve lived in the Sydney region longer than anywhere else: it has more than double Adelaide’s annual rainfall, it often falls in great intensity, and it was often a nuisance, flooding homes and disrupting traffic.

Adelaide invariably welcomes rain!  That special aroma is full of not only moist and gentle fragrance, but in our region it makes people, animals and plants sing in a special way.  We measure and welcome it for our garden and vegie patch.  It promises revival for everything green, raises hopes for the rivers, dams and farms, and brings back memories and hope of better times.

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