BGS Borehole Records and Choosing a Borehole Pump

Most people choosing a borehole pump start with the pump. Often the smarter place to start is with the borehole itself, because the numbers that decide which pump you need may already be on record. The British Geological Survey (BGS) holds the national archive of borehole records, much of it free to view online, and combined with a few figures from the borehole on the ground it tells you almost everything needed to specify the right pump. Here is how to read it, and how it turns into a pump choice.

Start with the BGS records

The BGS keeps a record of boreholes and wells across the country, and you can search them for free on the BGS GeoIndex map. Switch on the boreholes layer, find your location, and you can see where boreholes have been sunk nearby. Where a scanned record or log is available, it can tell you how deep the borehole went, the geology it passed through, and sometimes the water level and the yield it produced. Even if there is no record for your exact spot, nearby boreholes give a strong steer on how deep water is likely to be and what the ground is like, which is invaluable before you spend a penny on drilling or a pump.

If you already have a borehole, its own drilling log or pump-test report is the gold standard, and it should give you the four numbers below directly.

The four numbers that decide your borehole pump

A borehole pump lives or dies on four figures. Get these from the record or a pump test, and choosing the pump becomes straightforward.

Depth of the borehole

How far down the borehole goes sets how deep the pump can sit and is the starting point for everything else. A deep borehole needs a pump built to be lowered well below ground and to push water all the way back up.

Water level, resting and pumping

The rest water level is how high the water sits when nothing is running. The pumping (or drawdown) level is how far it drops once you start pumping. The distance from the pumping level up to where the water comes out, plus friction in the pipe, is the head the pump must overcome. This is the single biggest factor in pump selection, and it is why borehole pumps are high-head machines.

Yield, how much the borehole gives

The yield is how much water the borehole can sustainably supply, usually from a pump test. There is no point fitting a pump that draws faster than the borehole refills, as it will simply suck the borehole dry and damage itself. The pump's flow rate must sit within the yield, not above it.

Diameter of the borehole

The bore has to physically fit the pump. Boreholes are drilled to set diameters, commonly 4 inch or larger, which is exactly why borehole pumps are long and narrow. Check the pump's outside diameter against the borehole, with clearance, before anything else.

Turning the numbers into a pump

Put those four together and the pump almost specifies itself: a submersible pump slim enough to fit the diameter, sitting below the pumping water level, delivering a flow within the borehole's yield, at enough head to lift the water to the surface and onward to where you need it. This is the job borehole pumps are designed for, which is why they use stacked impellers to build high pressure from a narrow body. You can see the full range, with the head, flow and diameter for each model, in our well and borehole pumps collection. If you want the wider explanation of how head and flow trade off and which model suits which job, our guide to how to choose a well or borehole pump walks through it, and the pump curve guide shows how to read flow against head.

A quick word on the rules

Two legal points are worth knowing before you drill or pump. If you are sinking a borehole deeper than 15 metres, you must notify the BGS before starting work. And if you intend to take more than 20,000 litres a day, you will likely need an abstraction licence from the Environment Agency. We cover both in detail, including how the Environment Agency decides, in our guide to water abstraction licences.

No record, or a brand new borehole?

If the BGS has nothing for your site and the borehole is new, a proper pump test once it is drilled will give you the rest level, the pumping level and the yield, the same four numbers, measured rather than estimated. Either way, send us what you have, even if it is just a depth and a diameter, and we will help you match a pump that fits the bore and the supply. Browse the well and borehole pumps range, use the Pump Finder, or call the team on 0115 987 0358.

Frequently asked questions

Are BGS borehole records free to view?

Much of the BGS borehole archive is free to search and view online through the GeoIndex map, including borehole locations and, where available, scanned records. Some detailed records may need to be requested separately. Nearby boreholes are useful even when there is no record for your exact spot.

What information do I need to choose a borehole pump?

Four figures: the borehole depth, the water level both resting and when pumping, the sustainable yield, and the borehole diameter. Together these set the head the pump must produce, the flow it should deliver, and the diameter it must fit within.

Why must a borehole pump be long and narrow?

Because boreholes are drilled to set diameters, often 4 inch, so the pump has to fit inside with clearance. To build the high pressure needed to lift water from depth in such a slim body, borehole pumps stack multiple impellers in series.

Can I use any submersible pump in a borehole?

No. A standard submersible drainage pump is too wide and not built for high head. A borehole needs a purpose-built borehole pump, slim enough to fit and able to lift water from the pumping water level all the way to the surface and beyond.

Do I need permission to drill a borehole or pump from it?

Possibly. You must notify the BGS if drilling deeper than 15 metres, and you are likely to need an abstraction licence if taking more than 20,000 litres a day. See our guide to water abstraction licences for the full picture, and check with the Environment Agency.