In August 2026, a wildfire broke out near the A31 in the New Forest, closing the road for days and burning through a large area of gorse, peat and woodland. Crews from Hampshire, Dorset and Wiltshire worked around the clock in difficult conditions to bring it under control, and the scale of that effort deserves recognition first.
One detail of the operation stood out to us. With no fire hydrants in remote heathland, Hampshire & Isle of Wight Fire and Rescue Service set up a High Volume Pump (HVP) at Hightown Lake near Ringwood and ran hose roughly eight kilometres to the fireground, moving an estimated 1,300 litres of water every minute for days on end.
Working with pumps every day, it raised a question we get asked in a much smaller way all the time: how far can a water pump actually push water? The answer has surprisingly little to do with the number on the pump's spec sheet. It comes down to friction, flow rate and hose diameter. Here is how it works.
Fire crews pumped water around eight kilometres from Hightown Lake to the New Forest fire using a High Volume Pump and miles of large-diameter hose, delivering an estimated 1,300 litres per minute.
How far any pump can push water is decided mainly by friction loss in the hose, not by pump power alone. Friction rises steeply as flow increases and falls dramatically as hose diameter increases.
Get the hose right and water can travel a very long way. The same rule applies at every scale, from a national resilience pump set to the submersible in your basement.
What happened at the New Forest fire
The fire started as a vehicle fire on the A31 eastbound and spread into the surrounding heathland, eventually reaching woodland near Backley Bottom. Firefighters from three counties worked for several days to contain it.
Because the fire was in open countryside, there were no mains hydrants to connect to. The fire service's answer was to pump water all the way from Hightown Lake, laying a supply line across the landscape, in places crossing private land, to keep water flowing continuously.
Reports on the incident put that line at around eight kilometres (about five miles), delivering an estimated 1,300 litres per minute. That is a very long way to move water, and it is worth understanding how it is done.
How do you actually pump water 8km?
It is not just about the pump's rated head
Every pump has a maximum head rating, which is the vertical height it could lift water to if nothing else were working against it. Real jobs are rarely a straight vertical lift. As we explain on our pump terminology page, total head is the vertical lift plus every other form of resistance in the system, and on a long run the biggest of those is friction: the drag created as water moves along the inside of the hose.
That is the real story behind the 8km line. It needed to overcome the friction of pushing water through eight kilometres of hose lying on the ground.
The numbers behind the 8km line
The UK's standard HVP system uses 150mm delivery hose, with each pump set carrying up to 3km of hose and booster pumps available to relay water over longer distances, according to Gulf Fire's overview of the capability. We will use 150mm as an illustrative figure rather than a claim about the exact setup at every point of this incident.
Pushing 1,300 litres per minute through 150mm hose moves the water at about 1.23 metres per second. Over an 8,000 metre run, standard friction loss calculations put the resistance at roughly 74 metres of head, or around 7.2 bar of pressure lost to friction alone. In plain terms, the pump works as hard as it would lifting that water to the top of a 20-storey building.
And that is before any hills along the route, bends and couplings in the line, or the pressure still needed to actually deliver the water at the far end. Distance on its own is a serious job for a pump, even on flat ground.
Why pushing more water through gets hard, fast
If you try to force more water through the same hose, the effort needed does not rise gradually. It climbs steeply. Using the same 150mm hose over the same 8km, here is roughly what happens as flow increases:
| Flow rate | Water speed | Friction head (approx.) |
|---|---|---|
| 500 L/min | 0.47 m/s | 11 m |
| 1,000 L/min | 0.94 m/s | 44 m |
| 1,300 L/min | 1.23 m/s | 74 m |
| 1,500 L/min | 1.41 m/s | 98 m |
| 2,000 L/min | 1.89 m/s | 174 m |
| 3,000 L/min | 2.83 m/s | 392 m |
The pattern to notice: doubling the flow rate roughly quadruples the friction loss.
A note on pump ratings: a pump advertised at 7,000 litres per minute cannot deliver anything close to that through eight kilometres of hose. Maximum flow figures are measured with almost no resistance attached. Connect a long line and the achievable flow drops, which is also why two pumps with identical ratings can perform very differently once real hose runs and site conditions are involved.
Why not just use a wider hose instead?
This is where it gets interesting. Keep the flow fixed at 1,300 litres per minute over the same 8km and change only the hose diameter:
| Hose diameter | Water speed | Friction head (approx.) |
|---|---|---|
| 200 mm | 0.69 m/s | 17 m |
| 150 mm (the HVP standard) | 1.23 m/s | 74 m |
| 125 mm | 1.77 m/s | 183 m |
| 100 mm | 2.76 m/s | 559 m |
Same pump, same distance, same amount of water. Only the hose changed, and it made a huge difference. A narrower hose forces the water to move faster to shift the same volume, and that extra speed creates far more friction. It is why choosing the right hose diameter matters as much as choosing the right pump, whether you are running a discharge line out of a flooded basement or setting up a long drainage run on site.
Are high volume pumps used for floods as well as fires?
Yes. The HVP capability used at the New Forest fire is part of the UK's National Resilience programme, set up in 2003. There are now 51 HVP sets hosted across 40 fire and rescue services in England and Wales, according to Gulf Fire.
GOV.UK confirms these pumps have been deployed for seasonal flooding as well as major fires, moving floodwater away from homes and protecting critical infrastructure such as sewage treatment works and power stations.
The scale is very different from a domestic or site pump, but the engineering is identical. Every pump has to overcome lift and friction while still delivering the flow the job needs. We cover the smaller end of that scale in our article on the importance of pumps in a flood defence scheme, and our engine driven pumps range is built for exactly this kind of long-distance, high-flow work.
What this means for choosing your own pump
The takeaway
The New Forest operation was an impressive piece of work by the crews involved, and it shows just how far water can travel when a pumping system is set up properly.
The lesson for anyone choosing a pump is simple. Whether you are moving water eight kilometres across Hampshire heathland or draining a flooded cellar, if the hose is too narrow for the flow you need over the distance involved, no pump, however powerful, will make up the difference. Match the hose to the job, treat headline flow figures as best-case numbers, and the rest of the sums take care of themselves.
Frequently asked questions
How far can a water pump push water?
There is no fixed limit. It depends on how much friction the pump has to overcome, which is set by the flow rate, the hose diameter and the length of the run, plus any vertical lift. With wide enough hose, or booster pumps relaying the water, fire services have pumped water eight kilometres and more.
Why does hose diameter matter so much?
A narrower hose forces water to move faster to deliver the same volume, and friction rises roughly with the square of that speed. Dropping from 150mm to 100mm hose at the same flow can increase friction loss by more than seven times over a long run.
What is friction head loss?
It is the pumping effort lost to drag as water moves along the inside of a hose or pipe, expressed as an equivalent height of water. A pump overcoming 74 metres of friction head works as hard as one lifting the same water 74 metres straight up.
Can a pump really deliver its advertised maximum flow?
Only in near-perfect conditions with almost no hose attached. Once you add a long discharge line, lift or fittings, the achievable flow drops. Always size a pump against your real hose run, not the headline figure.
Are fire service high volume pumps used for flooding?
Yes. The UK's 51 National Resilience HVP sets, hosted across 40 fire and rescue services in England and Wales, are deployed for major flooding as well as fires, including moving floodwater away from homes and protecting infrastructure like power stations and sewage works.
