Definition of run (or come down) a banker in English:

run (or come down) a banker

phrase

Australian, NZ
informal
  • (of a river) flood to the top of, or over, its banks.

    ‘the creek is running a banker’
    • ‘Things were crook in Tallarook and everywhere else after the Hawkesbury River ran a banker and washed away houses, stock and crops which left the colony to face a savage diet reduction starvation.’
    • ‘The Wirreanda, and other creeks, were running a banker after more than seven centimetres of rain.’
    • ‘They were back just in time to be saved from the deluge which came down on 6 March causing the creeks to be flooded and the Cooper to run a banker.’
    • ‘You're not likely to get lost around these extra-wide streets with gutters deep enough to have a bath in when they're "running a banker".’
    • ‘I was also reminded that after Tony's last big birthday affair, the skies opened up and the normally dry dusty Todd ran a banker for a couple of days.’