Californian irrigation
Californian system or distribution by low pressure PVC pipe
The water is transported by an underground low pressure PVC pipe and distributed with pressure at the surface by several outlets disseminated in the garden. When the outlet is opened the irrigation is done by an existing gravity channel or by connecting one or two lay flat hoses to apply the water by spray or direct the flow to the plant.
The context
The water losses (around 60%) are very important during the transport of water in a ground channel especially in sandy soil and where sometime is not possible to dig channel. These losses increase the pumping time (fuel expenses and/or labour) and reduce the possibility to extend the surface of crop.
The various topography and the situation where the water point is located on a lower level of the garden don’t permit irrigation by gravity and the transport of water on the higher part of the garden.
During the dry season the distance to access to the water of a lake or a river can considerably increase.
The Californian system associated to a water lifting device (motorised or manual) can bring alternative solutions for the transport of water for irrigation.
The technology
The system is composed by PVC low pressure pipe (6 m length and around 2 mm thick) of 40 to 50 mm, according to the flow transited, and glued together. The pipe is put in a trench of 0.5 m depth to avoid damage by agricultural tools and by the degradation of the PVC by UV. The water is distributed by PVC or metallic outlets of 20 mm to 50 mm diameter and 0.2 m length out of the ground. The outlet is shut by handmade stopper made with a piece of PVC.
The density and the space between the outlets is variable according of characteristics of the field crop : 12, 18, 24, 36 meters. The diameter, the length of the pipe the number of outlets are linked to the topography, the soil, the crops and the method of irrigation and require a small study.
The application
The Californian system save water during the transport, reduce the time and the cost of pumping and it is recommended in sandy soils. It can transport the water on the higher and far away part of garden. The outlet can be used as an inlet depending of the proximity of the water point in case of an important withdraw of the water (river or lake).
The Californian system is a flexible installation adapted to budget and needs of farmers. The length of pipes and the number of outlets can be easily increased according to the financial and technical means. It can be used with a motor pump or a pressure treadle pump.
The Californian system is used in several developing countries : Niger, Mali, Burkina-Faso, Madagascar, Chad.
The facts
| Diameter | 40mm 50mm |
| Range of flow | 3 à 5 m3/h 5 à 10 m3/h |
| Max length of equipment | |
| - Spray irrigation | 48m 100m |
| - Gravity irrigation | 90m 200m |
| Number of outlets | 3 to 6 6 to 15 |
| Potential irrigated area | 0,25 to 0,5 hect 0,6-1,5 hect |
| Pipe | PVC low pressure |
| Diameter | 40 to 50 mm |
| Outlets | 20 to 50 mm metallic or PVC |
| Cost | 0.7 €/meter – 1 €/meter depending on country of implementation |
Training and introduction
PRACTICA can assist local plumbers or technicians on the design and installation of Californian systems, PRACTICA has developed a set of workshop and installation drawings, training and field tools.
PRACTICA also gives training to NGO and government extension staff who works with irrigation farmers to build up capacity in irrigation : irrigation techniques, crop water requirement, water management, irrigation technologies operation and maintenance.
