THE Cunningham Highway west of Warwick has re-opened after Mayor Ron Bellingham yesterday pleaded with SunWater to pull back on its release of water from Leslie Dam.
The mayor's intervention followed the closure of the highway to Inglewood yesterday morning, after Sandy Creek rose above the bridge just west of the Leslie Dam Road turnoff, forcing police and Main Roads to close the road.
The first release of water through the Leslie Dam floodgates in more than two decades – which started late on Wednesday night – was as spectacular as it was problematic yesterday, leading Cr Bellingham to call senior SunWater officials during the afternoon.
As a result, State-owned SunWater moved about 6pm last night to partially close the dam gates, acknowledging there was a need to “pull back the throttle”.
The highway west of Warwick was re-opened late last night by Main Roads after SunWater closed all but two gates in the dam wall as a result of the mayor's intervention, but motorists are urged to proceed with caution.
It was initially feared the highway to the west could have remained cut until this evening due to the volume of water released from the dam.
Periodic closures of the highway at Cunningham’s Gap today and tomorrow also added to the mayor’s concerns yesterday about highway access into and out of Warwick.
The closures were announced late yesterday by Main Roads (see below for more details).
While the sight of millions of litres of water from recent rains thundering down the spillway into Sandy Creek was a photographer’s delight, Cr Bellingham was yesterday critical of a lack of notice to Main Roads and the council of the timing of the water release.
While it had been tipped to happen this week depending on rain conditions and inflow into Leslie Dam, the mayor also said he believed the implications for local roads of such a large release had “not been fully understood” by SunWater.
“I guess part of the issue may be that it’s been 22 years since Leslie Dam was last full and perhaps there is no one around who remembers how that was managed,” Cr Bellingham told the Daily News last night.
“I fully accept that there had to be a release of water from the dam but frankly I’m concerned that Main Roads did not appear to know about it – it was the police who came across the water cutting the highway.
“What I asked of SunWater is that they reduce the rate of release and extend it over a longer period.
“The arterial road access into and out of Warwick is vital and a lengthy closure would really hurt this community and we also have the added issue of closures at the Gap on the other side of the town (today and tomorrow).”
Cr Bellingham said the weather had been on our side with the rain tipped to ease today.
“The threat of flood has eased and what we are now looking at in the Condamine is more of a fresh – had the rain kept up, obviously we could have been facing another extreme floods scenario".
The mayor said a “review of the dialogue” between SunWater, Main Roads and the council was needed and while he conceded a council engineer had been notified of the impending release on Wednesday night, council was unaware of the “quantum”.
However SunWater told the Daily News there had been contact with “all relevant local authorities” to advise them of the release.
SunWater southern area operations manager Peter Collett said the release of the dam water was “mirroring the inflow” and as the rain eased, so too would the release rate.
“It’s at 101.4 per cent (of capacity) currently, we’re releasing 26,000 megalitres per day (about 300,000 litres per second),” Mr Collett said, with figures current at 5pm yesterday.
“Mr Collett said Wednesday night’s release was by far the biggest event Leslie Dam had seen.
“We’ve never released this volume from the dam – it’s the largest we’ve ever done,” he said.
When the dam hit 100 per cent of capacity at 9.15pm Wednesday, the computer-operated system alerted SunWater it had to release the water to ease the pressure on the dam.
“The gates are automated in that when they reach certain trigger points they open, but we’ve got people on site monitoring 24 hours a day,” Mr Collett said.
“With the gated dam structure, they’re not designed to hold more than 100 per cent. We don’t want to compromise the dam.”
As of 6pm last night, the water release rate was scaled back to 18,000ML/day with it being reduced to under 10,000ML/day by midnight.
“We will stop releasing the water when it’s back to 100 per cent,” Mr Collett said.
“We’re looking in the next day or two to reduce the release rate slowly, but then there’s more rain forecast later this week, so we’ll just have to see what happens.”
Leslie Dam levels have been high enough to reach the gates only twice since it was upgraded in 1986, with September 12, 1988 the highest on record when it reached 20cm above the spillway. The second time, on May 28, 1990, was when it reached 13cm over the spillway.
The lowest Leslie Dam has been was on February 11, 1995 when it was at three per cent of capacity.
A SunWater spokeswoman has advised they would continue to monitor inflows into the dam’s catchment and based on that data will operate the dam’s floodgates in line with established dam operating guidelines.
“SunWater has contacted all relevant local authorities to advise them of the water release and the course of action being taken and will continue to liaise with them and other stakeholders as required,” she said.
“SunWater is also appealing to the community, and particularly young people, to stay away from and not swim or play in or around overflowing dams or weirs.”
It is understood one motorist who ignored road closed signage on the Cunningham Highway at Sandy Creek was washed off the bridge and their vehicle had to be towed out.
Gap closures today, tomorrow
Main Roads announced late yesterday the Cunningham Highway at Clayton’s Gully below the Gap would be closed for several periods today and tomorrow so urgent work could be carried out on a problem section of the road which keeps cracking.
The highway to Brisbane will be closed between 7am-8am, 9am-10am, 11am-midday and 3pm-4pm today (Friday) and tomorrow.
Motorists are asked to time their trips over the Gap in line with the closure periods.
Only one lane has been operating of late at Claytons Gully, with cracking of the road surface first detected there in early December and caused by soil slippage in the gully which runs beneath the road.
A Main Roads spokesman said the closures were unavoidable due to “recent extreme weather conditions”.
Mayor Ron Bellingham last night agreed the closure program was “complicated” but it was a better option “than the damn thing being fully closed”, as happened before Christmas.
He said he was concerned about the short notice period for motorists, but was confident Main Roads were “throwing everything they can at the problem”.
9.15pm Wednesday: Leslie Dam fills to 100% capacity.
10.30pm Wednesday: Floodgates begin to open.
By 11.40pm: All seven floodgates are open, with water released at a rate of 10,440 megalitres/day.
Noon yesterday: Water is being released at 21,000 ML/day.
5pm last night: Dam is at 101.4 % of capacity and releasing 26,000ML/day – equal to 300,000L/second.
6pm last night: SunWater scales back the release rate to 18,000ML/day.
By midnight: Release rate was expected to be back under 10,000ML/day.