Thanks for posting the warning signs @nzzp. I consider the DOC sign to be completely inadequate.
-
There is no mention of floodgates regularly opening. That would be enough to put off most people.
-
There is no mention of warning sirens. Presumably Ms De Jong and her friends had no idea what the sirens meant when they went off.
-
Instead of the very mild "Water level may rise" how about "Raging torrents several times a day"
-
It only says swimming is not advised. This pretty weak considering the situation there and a previous drowning.