The NSW premier has pressed his case to raise the height of a major Sydney dam, after four flood disasters in the past 18 months, while standing in a world-leading flood mitigation facility in Japan.
Wrapping up the first leg of his 10-day Asian trade tour, Premier Dominic Perrottet on Sunday visited the Ryu-Q Kan facility, one of the world's biggest underground drainage channels, on the outskirts of Tokyo.
