How much rain to fill the lake again?

We have finally had some good rain . The heavier soils in the catchments of Lake Colac are wetted up, so there is a good chance over October and early November for some significant runoff into it.
However, even above average rainfall over that period is unlikely to change the lakes prospects of being anywhere near full by the end of this year.
--So will it ever come back ? Yes the lake will fill again, but it will most likely take a series of wet years with runoff starting a lot earlier in the year than this year.
--Do springs make a difference to the lake? ;
--Does it leak ? and other questions - click here ,