Centenary of the O'Shannassy Water Supply System - 1913 to 2013 - a Pictorial Heritage

1924 - Modifications and Enlargements

1803 - Beginnings
1892 - Surrey Hills Reservoirs
1911 - Design and Construction
1911 - The O'Shannassy Weir
1914 - Maintenance and Operations
1923 - Bushfires, Landslips, and Floods
1924 - Modifications and Enlargements
1927 - Silvan Dam
1927 - Mt Evelyn Aqueduct
1928 - The O'Shannassy Reservoir
1929 - Upper Yarra Conduits
1931 - Silvan Inlet Aqueduct
1996 - Decommissioning
2006 - Pigging Project
2007 - O'Shannassy Aqueduct Trail - Overview
O'Shannassy Aqueduct Trail - Parrot Rd to Don Rd
O'Shannassy Aqueduct Trail - Don Road to Dee Rd
O'Shannassy Aqueduct Trail - Dee Rd to Sussex St
O'Shannassy Aqueduct Trail - Sussex St to Yuonga Rd
O'Shannassy Aqueduct Trail - Yuonga Rd to Donna Buang Rd
O'Shannassy Aqueduct Trail - Donna Buang Rd to Cement Creek Rd
O'Shannassy Aqueduct Trail - Cement Creek Rd to the Weir
The Present
The Author's Websites

Brick capping visible (2012)

1924 - Modifications and Enlargements


During the 1920's Melbourne's need for water seemed insatiable and as the construction of Maroondah and O'Shannassy storages fell behind schedule, other options to rapidly augment supplies to Melbourne were pursued.

In 1924 works commenced to increase the height of the walls of the O'Shannassy aqueduct so it could carry a greater volume of water.  The inverted siphons were also duplicated to provide for the inceased flow. 

By increasing the height of the channel walls by a relatively small amount - top width was increased from 9 feet 3 inches to 12 feet 11 inches and depth increased from 3 feet 4 inches to 5 feet 2 inches  - the capacity of the aqueduct was effectively tripled from 90.7 megalitres (20 million gallons) per day to 272 megalitres (60 million gallons) per day (although, in practical terms, the aqueduct ran "full" at 50 million gallons per day). 

The color difference and the join in the cement walls of the aqueduct are still clearly visible.
  A number of other aqueducts serving Melbourne were also enlarged at the same time.

Open channel c.1920

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