Ragnabo Data

Controlled Drainage & Irrigation Website

Controlled Drainage

The CDI technique can be added on top of existing drainage system. The CD-part (Controlled Drainage) is damming up the water table and provide passive irrigation to the plants. Rain water will not drain out as the dam will let it accumulate upstream  in the soil. This means that a given rainfall will last much longer to the plants.
At harvest time the control well is opened to secure machine driving.

By adding the I-part, that is adding water above the dam, irrigation can be accomplished even in dry season.
The different parts of CDI technique are depicted as additive lego parts in figure to the right.

Typically flat land gives large service area per dam because the damming function is horizontally. In fact irrigation service area is a bit larger because of the fact that plants are sucking water from soil.

The CDI technique therefore  offers continuously irrigation at low cost on a daily and weekly basis over large areas without moving equipment around.

Investment cost depends on land topography as well as how well the existing drainage system is adapted for the CDI technique. Some modifications to drainage system must normally be done.

The knowledge of existing system and its draining quality is important. Specifically, accurate maps are required when adding irrigation to existing drainage systems.

Note that:
Controlled drainage can only be implemented where there is a need for drainage in the first place. This will guarantee that there is sufficient clay layer at the bottom of the soil to prevent the water to drain down vertically.

More info:

Key values

Add On features
Continuously irrigation
Low energy
Low waste of water
Low maintenance cost
Easy managing