RAINFALL levels are the second-lowest in more than a century.
Figures from the Bureau of Meteorology show the Northern Rivers has only received less rainfall over the past 12 months once since records began in 1902.
BOM senior climatologist Agata Imielska said the Northern Rivers had experienced "significant" dry periods as well as above average temperatures.
"It's quite impressive how quickly these (rain) deficiencies have built up given that in 2010 through to 2012 we had very strong La Nina events and record flooding and very much above average rainfall," she said.
"And then we had quite a strong shift towards dry conditions, and particularly dry across north eastern NSW and south-east Queensland.
"Normally when we do get drier conditions they are associated with El Nino… but last year we didn't have an El Nino, but our temperature during 2013 as a whole, Australia had its warmest year on record."
Ms Imielska said the Northern Rivers has been given a 40-45% chance of exceeding the median monthly rainfall for the coming months.
"There isn't a particular push, in terms of these climate drivers, that is showing up that would mean either above or below average rainfall," she said.
Ms Imielska said climate conditions were affected by drivers such as La Nina or El Nino phases, southern annual mode, Indian Ocean Dipole and day to day weather fluctuations.
"This winter so far has been quite an interesting one in the sense that there's been things going on with each of these drivers pointing in different directions," she said.
"It's almost like a soup of climate drivers and it's not necessarily clear which one's the most dominant but they're certainly all interacting together."
Rocky Creek damn levels are the lowest they've been in five years with the current water level at 80%. For the past five years during the same period the water level has been about 99-100%.
Levels were at their lowest at the end of March this year.