Shoalhaven City Council has begun digging a channel to the sea at Shoalhaven Heads after water levels rose overnight in the Shoalhaven River.
The water level at Nowra Boat Shed at 5.47am on February 10 reached 3.0m AHD, the emergency level.
People are requested to stay outside the work area and keep away from the edges of the dug channel and eroding banks following opening as these areas are very unstable and unsafe.
It is expected that the low-lying areas around the lake will be subject to flooding and people should put in place their flood emergency plan. Council is reminding residents that anyone needing assistance should contact the SES on 132 500.
Flood safe information can be accessed from the SES FloodSafe website
For the latest weather forecast see www.bom.gov.au/nsw/forecasts/