Design Challenges when Draining The MCG

Gravity can give mixed results when it comes to standard drainage. For the MCG’s Great Southern Stand it was not enough to adequately drain the seating plats [levels], which meant rain and spilled drinks frequently ended up on the heads of people sitting in the lower levels.  The seating plat drainage system also has to cope with significant flows during washdown after events, but due to the high content of food and drink waste that goes along for the ride, this water must be treated before it enters the stormwater system.

Traditional downpipes wouldn’t work for draining either rain and drinks or washdown water, as they block the view. And putting pipes into the slabs would have required major works.

Why was vacuum a solution?

Avac’s system pulls the waste water back upward and transfers it to the grandstand core. The system features a PLC controlled vacuum centre and electronic field equipment, which monitors and controls the drainage in response to conditions in the plats.  From a construction point of view, Avac’s system was a real winner, by providing a solution which minimised construction cost.

Vacuum plumbing has several major advantages over gravity plumbing and waste systems, most of which can translate to cost savings. Virtually any building requiring drainage can realise construction, and operational cost savings through a range of features unique to vacuum plumbing.

The first of these features is flexibility. At the MCG Avac were able to route the drainage lines around obstacles with ease.  Vacuum can pull water uphill. Because they obstruct the view of spectators, downpipes were not an option and other alternative drainage systems were not capable of adequately dealing with the volume of water, Avac’s vacuum drainage solution was implemented. Our system brings light rain and washdown water back upwards by as much as 5 meters. It is then sent to a vacuum plant room where, depending on conditions, it is diverted to sewer or stormwater.

The other positive result is users of the Grandstand will not have to wear whatever the people above them have spilled!