Rainfall had been mostly coastal or along the alps in the past week, with only 4mm falling at Marino Ridges in Central Otago and 2.6mm in Middlemarch, compared with 10.5mm at Pine Hill in Dunedin and 16.5mm at Clifton Falls in North Otago.
Otago Regional Council environmental information and science director John Threlfall said river levels, especially the Taieri, were very low, but it was not unusual for the time of year and could turn around, given January was usually a high rain month.
Rainfall so far this month, even in coastal areas, had only been enough to give a brief respite before higher temperatures and wind meant river levels were dropping back again, he said.
"It's not been enough."
The Taieri River was at its lowest 10% of flows for the month and many rivers were on or just about on their low-flow restrictions.
To ease conditions, low-intensity, long-duration rain was needed to get farmers through summer, he said.
"Now that everything is so dry and rivers so low, we'll need long-duration rain."
Forecasts were indicating what rain the region would get was to come from the west, which did not typically provide much rainfall for catchments like the Taieri, he said.
So if those conditions continued through to early January, river levels would be very low, he said.
"It's already browning off in places."
