Through the Canberra Times, I have discovered that ACTEWAGL have been releasing 130 megalitres a day for the year so far to keep the main dam at a safe level. This effectively doubles the inflow that I have measured, but I suspect that that is not the full picture. I believe that there must be further significant releases occurring from the other two dams. Why do I think this, even though ACTEWAGL say that these dams do not usually have such releases? Simply because inflows have been relatively low. I think that there must be continuous 'dribble' releases from the smaller two dams that probably again amounts to around 100 megalitres or so.
However, if that is not the case, we have had 14,000 megalitres from 176.2 mm of rainfall. That is again lower than I would have expected. Remember that the average rainfall for Canberra is 612 mm, with the average runoff 180,000 megalitres. Thus, I think that there must be something else going on - either in the hydrology or in the water management system.