If the water is deeper than about 6 to 7 metres below the pump – as in a borehole – you need a submersible pump. For rivers, dams, shallow wells and tanks you can use a surface pump: electric where there is power, diesel for long hours without power, petrol for light use. The size depends on the total height, pipe length and litres per hour.
1. Where is the water coming from?
Borehole or deep well. A surface pump cannot suck water up more than about 6 to 7 metres, and less in highland areas because the air pressure is lower. For a borehole you need a submersible pump that goes down into the water.
River, dam, pond or shallow well. If the water level is within a few metres of the pump, a surface pump works well and is easier to maintain.
Water tank, but pressure is weak. You need a pressure booster pump, ideally with a pressure tank so taps and showers stay steady.
2. What power is available?
- KPLC power – an electric pump is the cheapest to run. Check whether you have single phase or three phase.
- No power, long daily pumping – a diesel pump set.
- No power, light or occasional use – a petrol pump.
- Borehole with no power – a submersible pump run from a generator. The two must be sized together.
3. How high and how far?
Pumps are sized by total head – the total height the pump must push water, including friction in the pipes:
- Depth to the water level (for boreholes and wells)
- Lift from the pump up to the top of the tank or the highest point of the farm
- Pipe friction – roughly 5 metres extra for every 100 metres of pipe, more if the pipe is narrow
4. How much water do you need?
Some useful figures:
- A family uses about 500 litres a day
- A dairy cow drinks about 100 litres a day
- Drip irrigation needs about 20,000 litres per acre per day
- A day school uses about 10 litres per pupil per day
Divide the litres per day by the hours you will pump to get litres per hour.
5. For boreholes: check the yield
A borehole can only give as much water as its tested yield. A pump that draws more than the yield will run dry and burn out. Keep your borehole test report and share it with us – we match the pump to it, and to the casing size.
Get an estimate in a minute
Our pump sizing guide asks these questions and suggests a pump type and size. Send the result to us on WhatsApp and we will confirm the exact model before you buy.
Common questions
Can a surface pump draw water from a borehole?
Usually not. Surface pumps can only lift water by suction from about 6 to 7 metres, while borehole water is normally much deeper. A submersible pump is needed.
What HP pump do I need for a 10,000 litre tank?
It depends on the height of the tank and the distance from the water source. For a tank about 10 metres above a nearby source, a 1 HP pump fills 10,000 litres in a few hours. Use our pump sizing guide for your exact case.
This guide gives general advice. For your exact machine, follow the manufacturer’s manual or ask our team.
