Punmia’s example 8.4 showed a classic case: a hidden leak in a secondary branch, impossible to find by listening, but mathematically obvious if you calculated the nodal residuals. The margin note— “leak suspect” —was from some long-dead student, but for Arjun, it was prophecy.
He radioed the repair crew. As they clamped the leak at 2 AM, he heard a sound he hadn’t heard in weeks: a distant, rising gurgle in the overhead tank. Pressure was returning.
Three days later, water flowed for two hours. An old woman filled her matka and smiled at him. Arjun didn’t tell her about Hardy-Cross or iterative corrections. He just pointed to the repaired joint and said, “Page 266.” water supply engineering bc punmia pdf 266
Arjun grabbed his torch and a wrench. The night air was cool, smelling of dust and marigolds from the temple. He crawled under the concrete slab at Node 12. There it was: a longitudinal crack in the 150mm cast-iron pipe, half-hidden by a banyan root. Water wasn't gushing; it was weeping—twenty liters per minute, day and night, for maybe ten years. Enough to starve two thousand homes.
Arjun, a junior engineer in the arid district of Shekhawati, had been staring at that page for three hours. Page 266 contained the chapter on Design of Distribution Networks , specifically the Hardy-Cross method for balancing flow in looped pipes. But he wasn't solving a textbook problem. He was solving a crisis. Punmia’s example 8
That morning, he had borrowed the only ultrasonic flow meter in the district and walked six kilometers of pipeline, recording data at every valve. Now, back in his office—a tin shed with a flickering tube light—he punched the numbers into a spreadsheet he’d built from Punmia’s iterative method.
And somewhere in the ghost of that textbook, B.C. Punmia’s equations did what they were meant to do: bring water to the thirsty, one node at a time. As they clamped the leak at 2 AM,
The first iteration failed. Residuals scattered like frightened birds. The second, worse. By the fourth, a pattern emerged. Node 12, a junction near the old Hanuman temple, showed a correction term of +0.32 m³/hr—small but persistent. According to Punmia’s logic, that meant water was leaving the system there, not reaching the end users.