The Tumut River is expected to be somewhere between the minor and moderate flood level for at least the next four to five days.
Water NSW will dramatically increase releases from Blowering Dam from today to create airspace in the water storage.
The Bureau of Meteorology on Thursday morning issued a minor flood warning for the Tumut River for tomorrow morning.
The Bureau warning predicted the river will reach the minor flood level of 2m Friday morning.
However, Water NSW and the SES have indicated the river will exceed the minor level, and it will be for some time.
Water NSW has indicated it will initially release water at the rate of 12,000 megalitres a day (at the dam).
The dam releases will combine with the Goobarragandra River, which had a flow of about 7,000 megalitres, producing a daily flow of up to 20 gigalitres in the Tumut River at the Tumut gauge.
“The flow rate is expected to reach 15.5 gigalitres at Tumut on Thursday night, which is above minor flood level, and then hopefully increasing this to 20 gigalitres late on Friday, which is between minor and moderate flood level,” Water NSW communication co-ordinator Tony Webber said yesterday.
“We are hoping to make some airspace in the dam to absorb upstream inflows generated by rain forecast by the Bureau of Meteorology.”
The releases would mean the Tumut River, at Tumut, will rise to somewhere between the minor (2m) and moderate (2.5m) flood levels.
Water NSW held conferences with the Bureau of Meteorology, State Emergency Services, Local Government and Snowy Hydro this week.
The SES has been door-knocking in the Tumut area to keep people informed.
Jon Gregory, from the SES, said the releases from Blowering were necessary.
“It’s a case of wearing some short term pain, to avoid much more pain later on,” Mr Gregory said.
“Blowering, Burrinjuck and a large part of the Snowy Scheme are at capacity and we need to make room in Blowering.”
Inflows into Blowering were at just over 13,000 megalitres a day up to Thursday.
The SES expects the river will be high for a number of days and impact on low-lying streets in Tumut such as River Street, Elm Drive and Tumut Plains Road.
The Rivergalde Caravan Park may again be impacted, but no houses are expected to be at risk of inundation.
“It’s mainly the rural landholders that will be impacted,” Mr Gregory said. “The plan is, basically, to let out as much as possible in as short a time frame as possible.
“If we don’t, we face the possibility of an uncontrolled spill out of Blowering.”
Mr Gregory said flood levels at Gundagai and Wagga will also be taken into consideration.