Lining irrigation canals reduces seepage losses, prevents waterlogging, protects against weed growth, and permits higher non-scouring velocities. For maximum hydraulic efficiency, a lined canal section must yield maximum discharge $(Q)$ for a given cross-sectional area $(A)$ by minimizing wetted perimeter $(P).$ For a rigid trapezoidal lined canal with side slope $m$ (horizontal) to 1 (vertical), the most hydraulically efficient section satisfies: $$R = \frac{y}{2}$$ Where $R$ is the hydraulic mean radius $(R = \frac{A}{P})$ and $y$ is depth of flow. When side slopes are set at $60^\circ (m = 1/\sqrt{3}),$ the section becomes a semi-hexagon. Discharge is computed using Manning’s equation: $$Q = \frac{1}{n} \cdot A \cdot R^{2/3} \cdot S^{1/2}$$ Where $n$ is Manning’s roughness coefficient and $S$ is longitudinal bed slope. Legacy concrete-lined canals in major command areas like the Indira Gandhi Nahar Pariyojana (IGNP) suffer from joint degradation, structural cracking, and hi...