Can someone think of ideas on how to harvest tons of water that overflow during Monsoons

I practice n preach everyone on how to save water, even the half glass that remains unused....

Then during Monsoons, gates open and tons are wasted....

Can we not build huge big artificial lakes where the water can be siphoned to ???

Please think if it can be diverted to deserts, or empty lakes where the rainfall is scanty.

Please do pour in suggestions.

Armin Dutia Motashaw