In my view the problem stems from us losing Siachen Glacier. For Pakistan, it is imperative to take back Siachen and establish a seamless border with China's Aksai Chin. India can carry out all the river flow diversions it wants. When it loses Siachen, it will be confronted a unison front, opposed by both Pakistan and China. Strategically speaking, Pakistan Military needs to focus on how to take back Siachen, more than the Vale of Kashmir itself. Retaking Siachen and establishing a permanent Air Base, would permit Pakistan Military to focus it's entire attention towards coordinating with China on eroding Ladakh border.
This would essentially force India to rethink it's strategy and buy Pakistan time to consolidate and solidify it's positions in Siachen for permanent presence.
Also, not to forget that Pakistanis must focus their attention as civilians, to ensure planting the billions of trees that is envisaged in Prime Minister Imran Khan's ambition. Not just planting them, but also ensuring that the reforestation of Pakistan's landscape is continued uninterrupted and expanding steadily.
Water storage, cloud seeding of Baluchistan, planting trees in Sindh and establishing a network of desalination plants across Pakistan's coastline, are essential to cut of the snake's (India) head and it's efforts to undercut us.