Powerstation Tailrace dewatering

Snowy Hydro needed to inspect the condition of the tailrace of Tumut 1 Dam. We were required to do the pump out in 2 days. Pumps and piping were set up at our works and all the gear tested. We used poly pipe mounted on wheels to lower down the tunnel as the water level fell.
	The tunnel was drained as far as possible by gravity and then the pumps were set up at the tunnel mouth. Pumping proceeded for 24 hours a day in multiple shifts.
When the tunnel was clear of water inspection crews drove into the tunnel to inspect the condition of the roof and walls.
	The water in the tunnel was discharged into the river.