Southern hydro lakes continued to spill water yesterday, but it was believed the worst of the rain was over.
Recent heavy rainfall in the mountains had resulted in water flowing into catchments at "phenomenal" rates, Meridian Energy external relations manager Claire Shaw said.
"Three days of rain caused us to spill right down the chain."
This meant water was being spilled from each of Meridian's hydro lakes on the Waitaki River.
Yesterday afternoon, at Lake Tekapo, 90cumecs was being spilled, 500cumecs at Lake Pukaki, 127cumecs at Lake Ohau, 820cumecs at Lake Benmore, 770cumecs at Lake Aviemore, and 380cumecs at Lake Waitaki.
The Environment Canterbury website said last night 1050cumecs were flowing down the Waitaki River which was expected to increase to about 1400cumecs.
Environment Canterbury and Meridian warned farmers and hunters to be aware of rising river levels and take precautions.
While further showers were forecast, Ms Shaw did not expect them to impact as highly on lake levels.
"Lakes are full and the main inflow event has moved on now," she said.
For the month of April, Lake Tekapo received 1596mm of rain, 986mm of which fell in the past three days, causing the lake to rise by 1.5m.
Rainfall of this amount was normally seen in spring and summer.
The last time spillage occurred in April due to heavy rainfall was in 1998, Ms Shaw said.
Contact Energy was also spilling water from its hydro lakes due to inflows remaining high, communications manager Jonathan Hill said.
Lake Dunstan and Lake Roxburgh were spilling 200cumecs yesterday and, with a "lot of water still coming into the system". it was set to continue.
However, Mr Hill was not concerned about the spillage as it was, comparatively, a small amount.
