Rebels said the real reason was to prevent a flood of refugees crossing escaping over the frontier.

One scientist uses the analogy of an overflowing bath; you must prevent the flood from bringing down the ceiling, but that's pointless unless you also turn off the tap.

The excavated earth was used to raise earthen embankments at some clearance around the lake in order to prevent the flood water from contaminating the tank.

A jetty system would prevent the floods by deepening the main channel.