First of all to you've got to understand that we can't dam all the rivers . The ones we can whose waters Paxtan is entitled to under the IWT will take time but more importantly will only reduce the flow not stop it.
However even that reduction is fatal to Paxtan as it's one of the most water stressed nation on earth as of the present. Theoretically therefore the situation 10-20 years from now when those dams & barrages are built will see Paxtan with a population of 300 - 350 million & in a much worse situation in every dimension leave aside water from what it is today assuming they survive as one nation that long.
Before their water wars with India explode they'd be fighting internal water wars. Check on the Green Pakistan Initiative wherein Fauji Foundation is planning a huge contract farming project in the Cholistan Desert comprising of lakhs of acres by constructing a series of canals diverting water from the Indus Water System meant for the Seraikis & Sindhis , both of whom are up in arms .
There's a very good chance Fauji Foundation in the not so distant future use India as bogeyman citing our keeping IWT in abeyance as a pretext to start a war to divert attention from the water wars being waged by Paxtan.
This is the reason I've stated before that the rest of the century is going to be action packed as far as we're concerned beginning with China next decade followed by Paxtan & the fallout of that nation splintering , then we've the malaun lungis on both sides of the border to deal with beginning with those outside our borders & finally the original Paxtanis in mainland India.
