Section outline

    • Irrigation Structures

      A. Diversion Headworks

      • Function: Divert water from a river into a canal.

      • Components:

        • Weirs/Barrages

        • Undersluices

        • Fish ladders

        • Guide bunds

      B. Canal Structures

      • Types:

        • Canal Falls – to dissipate energy in steep terrain

        • Canal Regulators – control water flow and level

        • Cross Regulators – maintain uniform flow

        • Outlets – supply water to fields

      • Design Aspects:

        • Hydraulic design

        • Structural stability

        • Sediment control

      C. Water Conveyance Systems

      • Lined vs. Unlined Canals

      • Pipes and Drip Systems

      • Sprinkler Irrigation

      Drainage Structures

      A. Surface Drainage

      • Purpose: Remove excess water from the land surface.

      • Structures:

        • Open drains

        • Field drains

        • Collector drains

      B. Subsurface Drainage

      • Purpose: Remove water from root zones.

      • Methods:

        • Tile drainage (pipes laid below ground)

        • Vertical drainage (pumping wells)

      C. Drainage Channels and Culverts

      • Design Parameters:

        • Rainfall intensity

        • Soil permeability

        • Crop tolerance to waterlogging  

      Design Considerations

      A. Hydraulic Design

      • Manning’s equation for channel flow

      • Flow velocity, discharge, and slope

      • Seepage losses and lining requirements

      B. Structural Design

      • Load-bearing capacity

      • Foundation design

      • Use of concrete, masonry, and earthen materials

      C. Environmental & Economic Aspects

      • Water conservation

      • Cost-benefit analysis

      • Impact on ecosystems