Revision history [back]
You might want to look at the rope-washer pump: http://www.pumpaid.org/our-work/adziwa/ Pump Aid is in Malawi, this is an example of a pump at an Orphanage. As it is a lift pump (not suction) it can cope with lifts of up to 30 metres. For most suction pumps, especially at the altitudes in Malawi, your practical limit is probably about 5 metres for a pump in good condition (see http://www.fao.org/docrep/010/ah810e/AH810E04.htm for a useful discussion , section 2.1.5). The rope-pump can be adapted to pedal power (if it is to be used for irrigation).