All major rivers in Indian sub-continent origins in Tibet area of China.
Pakistan should ask China to divert the rivers Indus, Satluj , Ganges and other to Pakistan via "water tunnels/chanels" if and only of India vioates Indus water treaty.
Make that as part of CPEC. Win Win situation for both China & Pakistan. China gets shorter & safe route to middle east and Pakistan gets river water from Tibet that India wants to stop.
The engineering work is not done in one day, but atleast one can start it.
Agar itna asaan hota, to kab ka ho chuka hota, it will have dire consequences, not even USA can do that, especially since India and China has not as much hostility as Pakistan,even then India hasn't done it.