Sydney water supply, rainfall history and seawater desalination issues

Falling dam levels in recent years are ringing alarm bells in Sydney about future water supplies.   This website by Warwick Hughes email inward at sign  will attempt to present objective data describing the history of all the factors involved in understanding how Sydney has arrived at this position.
To quickly sum up;
For comments on CSIRO has claims that since 1950 NSW rainfall has been declining at 14.3mm per year.
Click on  graphs for full screen versions
Dam levels
Graphic of dam levels in Megalitres from Jan 98,  Sydney Catchment Authority web site  A short history of Sydney's water supply can be read at and it is obvious that droughts and  periods of cyclic low rainfall have driven water policy in NSW for over 150 years.   In view of the obvious realities of our rainfall history you would think water managers would learn to plan future water supplies in periods of elevated rainfall.

Andrew Mitchell's site packed with graphics and stats on Sydney water supply and dams.
The media runs too many gloom and doom stories with green prophets invoking greenhouse :"climate change" and linking this to :talking of permanent dryer times ahead.  Since 2002 there has been a general media beating up of drought stories with the 2002 event  exaggerated as something unprecedented when it was just another cyclic El Nino drought.  Run of the mill storm events are also beaten up as exceptional.   The Cataract Dam 1904-2004 rainfall history shows 2002 and recent times to be nothing exceptional.  The blue trend is a 5 year rolling average.
Cataract dam monthly rain 1904-2004
The points I am making contrary to the general media hype is that Sydney catchment rainfall is no lower than several previous periods eg around circa 1994, 1979-84, 1934-42, 1904-1910.
 The well quoted Tim Flannery (of "Perth will die" fame) is even referring to normal high rainfall events as "freak", to bolster his vision of ongoing drought.
See Sydney rainfall page for more graphics. Policymakers must be very careful to separate fact from fiction in all this media frenzy or NSW taxpayers will be saddled with multi-$Billion desalination plants costs forever.  More rainfall data will be posted as it comes to hand

An example of recent media articles touching on Sydney water issues is Paul Sheehan's 24 April 2005 SMH at;

CSIRO greenhouse climate model predictions of hotter/dryer times ahead are quoted to denigrate future dam options as though these models have a track record of success.
In fact the best BoM models have a very poor  track record modelling rainfall and temperature only 90 DAYS ahead.
The water managers should have planned long ago for periods as dry as the present.
Water supplied post 1950
Demand and population have steadily expanded to outstrip supply, put together with a cyclic low rain period,   presto the falling and stubbornly low dam levels.
This graphic is from a NSW Parliamenty Briefing Paper No 4/2004, "The Future of Water Supply" by Stewart Smith and presents annual water supply in gigalitres (GL) (see units Table at page bottom. Stewart Smith's paper can be found at

To what extent has increased areas of National Parks alienated new dam resources near Sydney ?
Of course there is a whole constituency promoting seawater desalination, sellers of the technology, construction firms, water managers will have new staff positions, career paths, overseas trips and higher water prices must be more exciting for water managers than boring old selling cheap dam water at cost plus.
There is secret wining & dining and general schmoozing of policy makers by pro desalination interests.  Who knows what distortions are being presented by these salespeople.
Right now in May 05 I gather desalination proponents are preparing a report for the NSW Govt. 
I wonder if they are mentioning the effect rising energy prices will have on future desal water cost.
I wonder if they are pointing out that as soon as water is made in factories there will be water strikes.
Is anyone preparing a rational view of alternatives ?
In Perth and I suspect Sydney you can not get ordinary accounts of rainfall histories and statistics into the media, at the same time Govt water bureaux put out slanted biased information and of course these same Govt water authorities spend up hugely on advertising their spin on water issues in the media.
In Perth, slogans such as "our drying climate" and "independent of rainfall" are all part of Govt pro-desalination spin blocking out rational debate.
In Sydney the warmth in April was much reported on as something exceptional and a harbinger of Greenhouse. In fact many NSW and Australian met stations recorded similar hot Aprils going back to early last century and into the 19C.
Taken together with the standard media reporting of climate, weather, drought, a warm month, Greenhouse, Green issues, it all amounts to brainwashing of the public.
Perth has at least three other options to avoid seawater desalination but politicians have their minds made up, see below URL for  web site.
Perth Water Users sets out point by point how WA Govt mismanagement of Perth water resources is at the root of our so called "water crisis".
Perth Water Users (PWU) illustrated 6 May submission to the ERA  Inquiry on Urban Water and Wastewater Pricing - can be read on pdf file at
follow link under heading Submissions, to "Draft Report Submissions New!"; for our September 2004 3 page pdf submission click on "Issues Paper Submissions".

Melbourne dam levels have also caused concern recently and there are many similarities to Sydney with the same over-reaction to lowered rainfall and same swallowing of CSIRO Greenhouse climate modelling "hook line and sinker".

The public must come to realise that media reporting of all these issues contributes to this extravagant policy experiment into seawater desalination.
We need politicians prepared to state the truth about rainfall history, that current times we think are dry are similar to past cyclic lower rain periods and that our dams have served us well in the past and with the system prudently augmented by new dams and infrastructure, will continue to do so into future centuries.
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Units Used to Specify Water Consumption and Storage

One Gigalitre = one thousand Megalitres
One Gigalitre = one million kilolitres
One Megalitre = one thousand kilolitres
One Megalitre = one million litres
One kilolitre = one thousand litres
One kilolitre of water = one thousand kilograms = one tonne