Sandi, the King-Maker by Edgar Wallace

THE frontier between the Fongini and the Tofolaka country was delimitated by Nature when she laid the true course of the river which is called by the Tofolaka 'Bubukata', meaning 'the invisible river', and by the Fongini 'the river without water'. It is a form of humour in the Fongini country to promise that on a certain date you will wash yourself in the Mala, as they call it. For little water runs here, save a trickle in the rainy season, though there is evidence that at some time or other this was a fierce, strong stream, for the bed lies thirty feet below the level of the plain through which it runs, and this trench is broader than the length of twenty men.

There is a legend of floods in the Fongini country which is analogous to the legend of the Deluge.