Irrigation restrictions at the Opuha dam in South Canterbury have been lifted, but lake levels are still being monitored closely.
Irrigation from the dam was turned off in late February for the first time in its 17 years of operation as a result of the drought.
Opuha Water Limited chief executive Tony McCormick said the dam got to its lowest ever point of below 10 percent, so it was taking time to build water levels.
Mr McCormick said it had taken two months to get the lake back to 20 percent capacity, so they needed at least an average winter to fill it.
There are currently no consent-holders for irrigation.