Revealed: North Adelaide Service Reservoir is an underground ‘cathedral to water’ and architectural history
HISTORY MONTH: Hidden beneath city parklands, a secret chamber has gone unseen and virtually unknown to most Adelaideans for more than 120 years.
IT is one of Adelaide’s grandest structures, a 19th century architectural and engineering marvel that still serves a vital public purpose today.
Yet, chances are you have never heard of the city’s brick-vaulted “cathedral to water” because it is hidden beneath the parklands.
The North Adelaide Service Reservoir, built by the Hydraulic Engineers Department in 1879 to increase water pressure to the Port Adelaide area and allow for an improved sewerage system, is in line for state heritage protection.
SA Water says the 4.7 million litre tank, beneath a mound near the intersection of O’Connell St and Barton Tce, still supplies about 100,000 people and remains “a critical part of our water supply network”.
A South Australian Heritage Council report says it “represents a significant feat of hydraulic engineering in South Australian history”.
“It is a unique South Australian example of an underground reservoir,” the report says. “The quality of its design and construction were remarkable for its time and function; the utilitarian building being constructed using piers and arcades more commonly seen in grand neoclassical structures, creating a ‘cathedral to water’.
“The quality of its design and finish were particularly notable given the structure was never intended to be seen or accessed by the general public.”
The report adds it is an important marker in the state’s development, demonstrating “the growth of the colony, investment in infrastructure networks, and commitment to public health”.
The reservoir has a square footprint with sides of 33.5m and a height of 5.8m, 48 brick columns, and nine arched roof bays each with a span of 2.9m.
The two-layer concrete floor is almost 14cm thick, while the thousands of machine-pressed bricks were specially manufactured in Melbourne “to exacting dimensions and quality”.
While impressive, the North Adelaide reservoir pales in comparison to truly cathedral-sized historic reservoirs such as the Basilica Cistern in Istanbul – featured in last year’s Hollywood film Inferno and based on the Dan Brown novel of the same name.
That 6th century cistern measures 138m by 65m, with a ceiling supported by 336 marble columns.
The North Adelaide tank, accessed via the original pump house building on the eastern side, is usually full of water, except when drained every few years for maintenance.
An Adelaide Park Lands Preservation Association newsletter said it was a feature of the greenbelt “few South Australians would ever have seen’’ that “looks like a cathedral or vault”.
The reservoir has been given provisional state heritage listing.
The SA Heritage Register webpage for entries and confirmation is at: http://www.environment.sa.gov.au/our-places/Heritage/SA_Heritage_Register/entries-confirmations
SA Water has begun a five-month maintenance project to “address blockages, treat cracks on the tank roof and reconfigure existing surface drains”, as well as landscaping around the site.
It says the works “are designed to protect the historical architecture of the tank” and will have no effect on water supply to homes.