Annual flows have ranged from less than NUMBER@1 megalitres -LRB- NUMBER@2 acre-feet -RRB- in NUMBER@3 to as much as NUMBER@4 megalitres -LRB- NUMBER@5 million acre feet -RRB- in NUMBER@6 .

In NUMBER@3 the flow was less than NUMBER@1 megalitres -LRB- NUMBER@2 acre-feet -RRB- . Six years later -LRB- NUMBER@6 -RRB- there was a flow of NUMBER@4 megalitres -LRB- NUMBER@5 million acre feet -RRB- .
