Lacey's Canal Design Theory and Design Steps

Lacey's Canal Design Theory
• This is an improved version of Kennedy’s theory.
• Lacey proposed that there were 3 types of regimes - True, Initial and Final regimes. As per Lacey’s theory:

• True regime channel can be achieved only if the below conditions are satisfied (Ideal conditions)-
• Channel has a constant discharge
• The channel is on coherent alluvial soil which is a loose soil that can be easily scoured as it is deposited.
• Lacey's Canal Design Theory
• Initial regime: it is the type of regime that appears having ideal conditions but not so because the width of the canal keeps on varying.
• Final Regime: As water keeps flowing, depth, perimeter, slope keeps varying which forms a final stable regime.
• Lacey's Canal Design Theory
• Lacey’s theory would be applicable to the final regime/true regime only. Similar to Kennedy, Lacey also introduced another term called silt factor.