As the floodwaters recede along the River Murray in South Australia, people are asking if the lock and weir system could have prevented some of the flooding.
The River Murray is dotted with structures that stop it from falling to its naturally low levels. The locks, weirs and barrages, build nearly 100 years ago, ensure that the river can always be navigated by boat, and farmers upstream can irrigate.
But what happens when there’s too much water – like in the most recent spate of floods? The wettest spring on record in southeastern Australia caused billions of litres of water rushing down the Murray each day. If we’d operated the locks and weirs differently, could we have prevented water levels from rising as much as they did?
Cosmos chats to Garry Fyfe, Senior Manager of River Murray Operations at SA Water, on how the locks and weirs work in ordinary times, and what happens when there’s a flood.