Predominant southeasterly winds, the significant northern drift of sand and wave climate combined to move an estimated 500,000 cubic metres of sand along the south-east Queensland coast each year.

Over time the Nerang River mouth moved northward by up to 60 metres each year, causing land erosion and changing sandbanks at the bar and adjoining Broadwater.

In the early 1800s the Nerang River entered the Pacific Ocean where Jupiters Casino is now located. In 1930 the entrance was where Seaworld stands today.

It was estimated that by 2050, the entrance would be opposite Runaway Bay if no action was taken, and the township of Currigee on South Stradbroke Island would be in danger.

Sadly, it was too late for Moondarewa. Moondarewa was a coastal town established on Stradbroke Island. In 1984 it sat in the centre of the Southport Bar and was lost forever to the volatile Nerang River entrance. This is a clear indication of the obstacle that the untrained Bar presented to development of the Broadwater and adjacent land.