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