Saudi chemical manufacturing depends on reliable water supplies for reaction media, steam generation, cooling, cleaning and utility services, yet conventional wastewater management often treats these interconnected demands as separate engineering problems. This critical review evaluates how intelligent water allocation, selective treatment and zero liquid discharge can be combined without assuming that maximum water recovery necessarily produces the best environmental outcome. Thirty peer-reviewed publications dated 2020–2025 were examined across industrial water networks, petrochemical effluent reclamation, membrane desalination, concentrate treatment, crystallisation and digital process control. Their evidence is interpreted for Saudi industrial clusters rather than presented as results from an unperformed local field study. The synthesis identifies four interdependent decisions: segregating streams before contamination is diluted; matching recovered water to explicit quality requirements; shifting the highest feasible proportion of desalination upstream of thermal concentration; and controlling residual solids, energy demand and operational reliability. A staged configuration integrates water accounting, biological or physicochemical pretreatment, ultrafiltration, reverse osmosis, selective polishing and final brine management. Digital monitoring can improve early detection of scaling, membrane deterioration and abnormal water losses, but models require calibration against site-specific chemistry. The review proposes a water–energy–salt decision framework and a validation agenda for Saudi chemical facilities. Its central conclusion is that genuinely sustainable discharge elimination requires accountable material balances, end-use protection and credible management of the recovered salt, not simply the installation of an evaporator.