What are the principles for designing irrigation canals?

Irrigation canal design balances: (1) Non-silting velocity - sufficient to transport sediment (~0.5-0.8 m/s), (2) Non-scouring velocity - prevent erosion (<1.0 m/s for earth canals), (3) Minimum section for required discharge, (4) Stable side slopes (1.5:1 to 2:1 for earth). Kennedy's theory relates velocity to sediment transport; Lacey's regime theory provides complete channel dimensions. Lined canals allow higher velocities (2-3 m/s), reduce seepage losses. Design includes freeboard, berm, and bank dimensions.