If you have allocated water, but it is unreliable (sometimes I am not allowed to take it) doesn’t that mean the stream is over allocated?

No. Reliability refers to how often you can use all of your allocation. Unless the minimum flow and level of allocation is low, it’s likely that users taking water from streams and rivers will have to stop or reduce their takes from time to time. This is not over allocation. Often these minimum flows are set at levels that are reached naturally in very dry years.

High allocation affects the frequency of restrictions but does not affect the frequency that no water is available to take.