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RedR TSS gravatar image
RedR TSS

My general view on upgrading traditional irrigation systems is “if it ain’t broke don’t fix it”. Generally traditional systems have grown up over time and have evolved a management system that works. Any imposed system that significantly alters the operation of a scheme may have disastrous consequences for management practices as well as traditional land and water rights. I was involved in a project to “modernise” irrigation schemes in Ethiopia and it is true that greater theoretical efficiencies can be achieved but tread carefully if there are any major changes. It is management systems rather than the hardware that generally causes the failure of communal irrigation schemes even if broken hardware is the symptom.

Having said the above if it is simply repairing what is already there then you will probably be OK.

As I understand it these systems are horizontal tunnels dug into a hillside to access an aquifer. There is probably not much you can do about the water resources available and any additional attempts to drain or pump more water might result in the existing systems running dry. What you can do is improve the efficiency of the use of what is flowing out of the hillside by one or more of the following options;

• Line, or repair the lining, of the transmission canals or even put the water into pipes which would reduce evaporation losses but might be expensive • Improve the in-field efficiency by changing from a flood irrigation technique to sprinklers or drip if the operating head is sufficient and there are suitable skills to maintain a more complex system • Reduce evaporative losses from the field surface by promoting mulching (if there is sufficient biomass) or even the more modern alternative of plastic sheeting.

The water on demand question could be a tricky one. I don’t know if the water flows and is used 24/7 or if there are periods when water is shut off, diverted into storage or flows to waste. In many irrigation systems there are night storage reservoirs to capture the overnight flow when the farmers leave their fields and go to sleep. It may be possible to increase the availability of water by introducing some storage but before you do that, check carefully about what downstream users are doing. Is any “waste” water being used by other farmers or animal herders further down.

Hope that this helps.

Best regards

Martin

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No.2 Revision
KnowledgePointAdmin gravatar image
RedR CCDRR

My general view on upgrading traditional irrigation systems is “if it ain’t broke don’t fix it”. Generally traditional systems have grown up over time and have evolved a management system that works. Any imposed system that significantly alters the operation of a scheme may have disastrous consequences for management practices as well as traditional land and water rights. I was involved in a project to “modernise” irrigation schemes in Ethiopia and it is true that greater theoretical efficiencies can be achieved but tread carefully if there are any major changes. It is management systems rather than the hardware that generally causes the failure of communal irrigation schemes even if broken hardware is the symptom.

Having said the above if it is simply repairing what is already there then you will probably be OK.

As I understand it these systems are horizontal tunnels dug into a hillside to access an aquifer. There is probably not much you can do about the water resources available and any additional attempts to drain or pump more water might result in the existing systems running dry. What you can do is improve the efficiency of the use of what is flowing out of the hillside by one or more of the following options;

• Line, or repair the lining, of the transmission canals or even put the water into pipes which would reduce evaporation losses but might be expensive • Improve the in-field efficiency by changing from a flood irrigation technique to sprinklers or drip if the operating head is sufficient and there are suitable skills to maintain a more complex system • Reduce evaporative losses from the field surface by promoting mulching (if there is sufficient biomass) or even the more modern alternative of plastic sheeting.

The water on demand question could be a tricky one. I don’t know if the water flows and is used 24/7 or if there are periods when water is shut off, diverted into storage or flows to waste. In many irrigation systems there are night storage reservoirs to capture the overnight flow when the farmers leave their fields and go to sleep. It may be possible to increase the availability of water by introducing some storage but before you do that, check carefully about what downstream users are doing. Is any “waste” water being used by other farmers or animal herders further down.

Hope that this helps.

* Update *

It appears from Google that the hill is on the other side of a major dry river bed from the irrigated area and the scheme itself comprises a large area of palms with some well managed and well laid out market gardening plots using surface irrigation canals. Some of the plots appeared to be out of use at the time of the image implying perhaps a shortage of water. If the falaj cannot yield any more water and there are no improvements that can be made in the water conveyance or infield distribution systems there might be possibilities for harvesting water from the main river or a drainage network flowing in from the east. I suspect that these only flow very intermittently. As I pointed out in my first post, there may be scope to go for a more efficient drip or micro-sprinkler irrigation system which would reduce water losses though have a high capital cost and probably higher operation and maintenance requirements.

Best regards

Martin