Hole 70 metres deep has opened up following collapse in Snowy Hydro tunnel, officials confirm

As Guardian Australia reported on Sunday, a major boring machine working on the Snowy 2.0 project had been halted after subsidence a short distance from the start of a tunnel near Lake Tantangara.

Launched by the Turnbull government, the Snowy 2.0 project is intended to add 2,000 megawatts of storage to the national electricity market. By linking two existing dams, the aim would be to pump water to the higher reservoir during periods of cheap electricity and release it through hydro plants when power prices are high.

Snowy is also facing delays on its other major project, the 660MW Hunter power project at Kurri Kurri, near Newcastle.

Barnes dismissed a question by NSW Nationals senator Ross Cadell that the ultimate cost could blow out to as much as $1.5bn.

Still, the project would only produce its first power by May 2024 and be fully operational by the end of next year, both about 12 months later than originally planned.

Barnes said the project review would be finished within six months but did not give a timeframe for when the hydrogen assessment would be ready.