A study on the "Trends and Regional Conditions in Irrigation andDrainage Canal Maintenance in Japan" reveals that:
The declining functionality of farmhouseholds and agricultural disadvantages associated with farmland location were moreimportant factors in deciding over the maintenance of the canals by the communities than theincrease of non-farmers;
More urbanized communities had less power to assign non-farmersto the maintenance of canals;
Urbanized or depopulated communities were characterized byhaving difficulty in maintaining the canals whereas the communities in the middle elevatedlocations succeeded in keeping up their maintenance;
There were regional differencesbetween the influences of the substandard farmland location on the maintenance of the canalsby communities.
Dear Edwin, can you share some material about the pump size to be used for particular elevation? Is it possible to pre-calculate the pump size depending just upon the elevation of the field from the canal ? can you help me in this regard?
Dear Scot. It's possible to estimate the pump size but you need a number of variables: water delivery (discharge) rate, pipe size (then calculate frictional head), static head etc.. Please refer to the FAO Irrigation Manual Module 5 found on the link below.
ftp://ftp.fao.org/docrep/fao/010/ai594e/ai594e00.pdf
Also check this link: http://www.pump-zone.com/december-2013-pump-sizing-efficient-irrigation
The common practice in Zimbabwe is pumping water to a night storage reservoir then gravitate it to the fields through canals. In some cases no pumping is necessary. For communal irrigation schemes in Zimbabwe, the idea is to reduce operation cost for rural irrigation farmers. However, most pressurized irrigation systems require pumping.
What is the orientation of the irrigation canals in relation to the fields for the farms you visited in Indonesia? If the fields are at a lower elevation than the canals, pumping is unnecessary unless it's a pressurized system and required pressure cannot be achieved through gravity alone. If fields are at higher elevation than the canals, pumping is necessary.
thanks for share Edwin. I had a question, when we visited last time to Indonesia we found out that farmers pull water from irrigation canals by motors. Which is obsoluetly of no need. Have you experienced such thing? And yes, community play a vital role in maintenance.