State Emergency Service volunteers staged two dozen flood rescues and responded to almost 600 requests for help across New South Wales over the past 24 hours as residents in Eugowra prepared to evacuate.
The SES advised river level rises had been observed along the Mandagery Creek upstream of Eugowra.
The creek was approaching a peak of around 8.2 metres with further rises to the major flood level of 9.10 metres expected from Saturday afternoon.
Residents had been asked to monitor river heights and be prepared to evacuate should conditions deteriorate. A flood evacuation warning had also been issued for Whittingham, Scotts Flat, Glenridding, Dunolly and Combo.
It came as Warragamba Dam spilled slightly after 9pm on Friday and was spilling at a peak rate of about 60-80 gigalitres a day on Saturday morning, shy of the 500GL that spilled at the height of the March floods. The dam was 100% full on Saturday afternoon.
“On current projections the spill could continue for up to a week,” WaterNSW said, adding “downstream impacts are likely”.
The SES assistant commissioner, Dean Storey, said it had been a hectic 24 hours throughout the state but particularly in the Upper Hunter, where new flood warnings have been issued.
“That continues to be where our focus is today,” he told the ABC on Saturday morning. “Scone and Muswellbrook were affected by floodwaters over the last 24 hours and will continue to be to an extent today, with the focus shifting downstream.”
Flooding is on the cards in Singleton on Saturday evening and then at Maitland into Sunday, Storey said.
However, the statewide situation remains volatile, with more than 20 watches and warnings active following a month of heavy rainfall.
WaterNSW said flows down the unregulated Mooki River in northern NSW appeared to be twice the height of any previous flow.
The flows were headed headed towards the Namoi River, which was a flood threat for Gunnedah, Boggabri, Narrabri, Wee Waa, Bugilbone and Goangra.
Major flooding was occurring at Jemalong along the Lachlan River where river levels peaked around 7.94m on Monday and remained steady over the major flood level. Downstream, Nanami was seeing moderate flooding, with further rises possible as flows from Canowindra arrived.
Further rain and thunderstorms were forecast across the Lachlan catchment into Saturday evening, which may cause further flooding at Jemalong, Condobolin, Eubalong, Nanami and Hillston.
Elsewhere, major flooding was occurring along the Belubula River at Canowindra and at Mandagery Creek.
Major flooding was also continuing at Wee Waa, Gunnedah and Jemalong with Narrabri, Coonamble and Singleton expected to exceed major flooding overnight and into Sunday.
Moderate flooding was possible at Yarraman by Saturday evening following a flood warning issued for Gwydir River. Minor flooding continued at Bathurst.
The SES warned that, with already saturated catchments and full dams, there was a “high chance” communities could experience riverine and flash flooding over the weekend.
WaterNSW said it was continuing to monitor storage levels at the state’s major regional supply dams, almost all of which were receiving constant inflows and were in excess of 90% of storage capacity.
“WaterNSW dam personnel are on round-clock flood operations at several dams, with the Keepit Dam on the Namoi River and Burrendong Dam on Macquarie River the primary regional focal points overnight,” the agency said.
Burrendong Dam (at about 130% full) received huge inflow volumes on Friday which pushed the storage to almost filling the dam’s 500GL flood mitigation zone.
Burrendong’s storage level rose 10 percentage points in 24 hours – including a 0.5% rise per hour for five hours – requiring overnight dam releases that reached 30GL/day before being scaled back to 5GL/day this morning to avoid increasing downstream river levels already rising due to high tributary inflows, WaterNSW said.
Keepit Dam cut releases almost entirely to avoid adding to a record flood peak in the Mooki River, due to reach Gunnedah later today.
Elsewhere, Chaffey Dam on the Peel River continued to spill in large volumes, while WaterNSW teams were monitoring inflows into Burrinjuck and Blowering dams on the Murrumbidgee, where successful storage operations were expected to have created sufficient capacity to capture the majority of inflows, WaterNSW said.
“This is quite a large statewide flood risk at the moment,” Storey said. “We are urging all communities and those flood prone areas to be aware of the risk and monitor the local conditions and follow the advice.”
The Bureau of Meteorology said some areas of the state had been hit with more than 100mm of rain on Friday. The downpour was likely to ease over the weekend but the risk of flooding persists.
Wee Waa could be cut off for more than a week due to the flooding, while a Rural Fire Service helicopter was called in to rescue a man trapped on the roof of his car in flood waters at Caroona on the Liverpool Plains on Friday.
Storey said it was a good time to stay off the roads.
The Oxley Highway was closed in both directions between Carroll and Gunnedah and the Kamilaroi Highway between Curlewis to Breeza.
At Muswellbrook, the New England Highway was closed in both directions.
Police say a Landcruiser was swept from a small causeway and carried 200 metres downstream by rising waters at Burrell Creek, west of Taree on Friday afternoon. Two men waded in to rescue the 65-year-old trapped driver but also became stranded. The trio were eventually hauled to safety by five police officers who fashioned a lasso from a length of rope.
Hunter Valley police also dragged a 52-year-old man from a spillway at Muswellbrook after his Toyota Hilux was swept 400 metres away by the current on Friday evening.
An RFS helicopter was called in to rescue a man trapped on the roof of his car in flood waters at Caroona on the north-eastern Liverpool Plains earlier on Friday.
The SES had responded to more than 3,000 requests for assistance since severe weather started earlier in the month – many for storm-related damage including leaking, damaged roofs and fallen trees.
In southern Queensland, six people including an infant child were rescued from flood waters as police issued a warning for motorists to avoid flooded roads.
Conditions were expected to ease by Sunday with little rain forecast across the nation.