The SA Life web site is an amazing treasure trove of history, and this segment on the Barrages contains some great footage from the time of construction.
Take a look at the video here: SA Life “Our Barrages”
If your keen on some historical specificity, you can check out “A short history of the River Murray works” from archive.org
This book is listed as published in 1900, but that’s an obvious error… given the information about the construction, and a photo of the completed Goolwa Barrage.