Robertson received record rainfall on the weekend, according to the Bureau of Meteorology (BoM).
BoM acting manager of weather services Mike Funnell said Robertson received 397mm from 9am on Sunday to 9am on Monday.
This was among the highest rainfall in NSW.
Mr Funnell said the day before was "significant", with 131mm from 9am on Saturday to 9am on Sunday.
He said this was a total of 528mm across a 48-hour period.
Mr Funnell said the rainfall in Robertson set several historic records for the village.
"[Saturday] was the highest day [for rainfall] since March 2017," he said.
"The 397mm is the highest on record, eclipsing the 1986 record [for Robertson]."
Residents can expect the rainfall to ease in the coming days.
"Main thing to bear in mind is the rain band has moved to the south east pushing into the ACT and across the Bega Valley," Mr Funnell said.
"We've got potential for severe thunderstorms today, tomorrow and Wednesday.
"There's still a lot of instability in the atmosphere. Check the radar and check our warnings."
The severe weather conditions kept NSW State Emergency Service (SES) Wingecarribee unit volunteers busy over the weekend.
Since 6am on February 9, the SES has responded to more than 130 requests for assistance across the Wingecarribee and Wollondilly shires.
The unit saw widespread requests for assistance with houses flooding and trees down.
Operational response manager Dylan Whitelaw said on Sunday night crews were unable to access Robertson due to safety concerns.
"Robertson RFS assisted us and completed some of the jobs," Mr Whitelaw said.
"We appreciate the community's patience as we respond to everyone's requests.
"Our teams operated throughout the night and will continue through today to assist the community."
As of 10.30am on Monday, the Illawarra Highway at Macquarie Pass remains closed in both directions. This is according to the Transport Management Centre.
Residents only may be permitted past closure points, at the discretion of emergency services.
Motorists are advised to avoid the area and use an alternative route.
Emergency services and Transport for NSW are currently monitoring the situation on Macquarie Pass.
According to Live Traffic, there is also flooding on the Illawarra Highway between Sheepwash Road and Church Street in Burrawang.
Traffic is affected in both directions and alternating (stop/slow) traffic conditions are in place.
Motorists are advised not to drive through floodwater, exercise caution and reduce their speed.
Visit the Bureau of Meteorology website for the latest forecasts and weather warnings.
If anyone requires assistance please call 132 500 or in life threatening situations, call 000.