The Things we Take for Granted: Water
In a post a few months ago I made one of those throw away comments I'm so fond of regarding Melbourne's water supply and a water tower. It occured to me then that I had no concept of Melbourne's water history - despite it's importance, nor what a water tower is - shamefully. It is a fascinating topic, and so this is the first of several posts on Melbourne's utilities up to and in the early years of the formation of the Melbourne and Metropolitan Board of Works in 1891.
But, first, a water tower. The water tower pictured in the Charles Condor painting is related to an unreliable supply of water, but not because there was none. Water towers are actually a way to maintain pressure during heavy usage. Melbourne's water in the 1880s wasn't that unreliable, having built several dams, but the pressure in the system was - and remained so until the 1960s in some higher areas, notably the posh middle eastern suburbs. Water towers were - and still are - an effective way of maintaining pressure, not maintaining supply. For that we need to go back.
Melbourne's first water supply was the Yarra river. A waterfall that lay where the Queen's Bridge now sits meant that the city could obtain fresh water, without being too distant from a place to moor ships. Water was drawn from just upstream of the falls and distributed on water-carts by private operators. But there were two problems.
Firstly, in times of drought - a common occurance then as today - the water level of the Yarra fell so much that the water became brackish and undrinkable. Second, and more importantly, the Yarra river basin represents the entire northern and eastern side of Melbourne. As such, industrial waste, human, animal and vegetable matter drained from the settlements into the Yarra river. By 1852, with a rush of new immigration at the start of the goldrush the Yarra was a sluggish putrid river. In the years to follow it would get progressively worse.
Sewage and water problems are not unrelated, but despite the establishment of a Board of Commissioners of Sewerage and Water Supply, only the water supply was addressed. The area around Melbourne was surveyed, and the Plenty River was decided upon as the best source of clean water. Works began on the Yan Yean Reservoir in 1853 and the supply was turned on in 1857.
The Yan Yean Reservoir in 1862 (courtesy: National Library of Australia)
However, the Yan Yean Reservoir was plagued by problems: first, the tin lining in the lead pipes was destroyed by voltaic action and dissolved, causing lead poisoning. Then, the quality of the water deteriorated. The Plenty River runs through swamplands, and despite works to route the river around them, the water had a "turpid opalescence... mawkish taste... repulsive smell" until into the 20th Century.
Not surprisingly, a constant supply of fresh water led to significant wastage. European gardens, and the hot weather contributed to people using far more than their counterparts in England. But, a policy of unlimited water for Melbourne had been established, and further extensions were made to the system: notably, the diversion of water from north of the Great Dividing Range into the Yan Yean Reservoir, and the building of the Maroondah Reservoir in 1891.
Today, the majority of the Yarra tributaries have been dammed - to prevent flooding if nothing else. Melbourne's potential water supply has probably reached it's maximum extent. Water already gets moved from the Thomson Reservoir into the system during a drought. The policy of maintaining an unrestricted water supply allowed and even encouraged untrammeled growth, but two questions remain: is this policy still in force? If so, how will it be maintained with another million people in 30 years time? And if not, what changes must be wrought in the way we supply water? Melbourne 2030 attempts to address this in Policy 7.1:
The Government will protect Melbourne’s water catchments and water supply facilities to ensure the continued availability of clean, high-quality drinking water. It will require that reservoirs, water mains and local storage facilities are protected from potential contamination, and that planning for water supply, sewerage and drainage works receives high priority in early planning for new developments.
Water use efficiency will be managed so that existing storages can reliably meet water demand beyond 2030. Sustainable management will ensure that water availability in other parts of Victoria is not adversely affected. Reductions are needed in per capita water consumption, which has already fallen by 12 per cent in the past decade, and in leakage rates, which are estimated as 8 per cent of potable water supply to Melbourne.
Making the answers to the above questions: "yes" and "by reducing demand and not increasing supply". Interesting times ahead.
Tales of the City
1st April, 2004 23:33:05
Water Green Paper...
Russ, there's a green paper discussing Melbourne's future water supply at the DSE's website:
Robert Merkel 5th April, 2004 13:27:57