No life can exist without water, and the water requirements of the average farm can be truly immense, especially if you grow particularly thirsty crops or crops that are not fit for harvest until after the driest summer months. Consequently, many farmers supplement their main water supplies by having water bores dug on their land.
However, a water bore is useless without some means of drawing the water it contains to the surface, and you'll need some kind of pump unless you're willing to stand over your bore lowering a bucket all day. Submersible water pumps are a particularly popular choice for water bores that come with a number of attractive advantages over other pump types. However, there are also one or two drawbacks to using submersible pumps, so you should familiarise yourself with these pros and cons before you decide on the right pump for your needs.
Why should you choose a submersible pump for your water bore?
Although the actual efficiency of your submersible pump will depend on the specific model you choose, as a general rule, they use far less energy than external, surface-level pumps (such as jet pumps) to provide the same flow rates and water pressure. This makes most submersible pumps surprisingly cheap to run, even for extended periods, and also reduces the environmental impact of your water bore as a whole.
Do not need to be primed
Since a submersible pump is fully submerged in the water inside your bore, it contains a ready supply of water at all times, and subsequently never has to be primed before operation. This allows a submersible pump to provide water on demand almost instantly, making it perfect for a water bore used to supplement unreliable water sources; as soon as your main supply cuts out, the bore can take over.
Being submerged in water also significantly muffles the noise your pump makes, and at the bottom of a reasonably deep water bore, a submersible pump can be practically inaudible. They are therefore ideal for water bores located close to living quarters and can be operated at night without causing a disturbance.
Immune to cavitation
Cavitation, an extremely damaging phenomenon caused by air bubbles forming around a pump's impeller, takes many surface-level pumps out of commission. Since submersible pumps are full of water at all times, no air bubbles can form, and cavitation cannot occur.
Why shouldn't you choose a submersible pump for your water bore?
Vulnerable to changing water levels
A submersible pump may not be a viable option if the water levels in your bore fluctuate significantly, as they must be constantly submerged to function effectively—activating a dry submersible pump will cause it to overheat and become damaged very quickly.
Difficult to maintain
As you can imagine, servicing and maintaining a pump that is constantly situated at the bottom of a deep water bore can be tricky at best and generally requires professional assistance. You should only choose a submersible pump if you are prepared to handle the cost of professional repair services, although their reliability means that this should only be a very occasional expense.