UK Water Sprinkler Storage Tanks
When a fire engine turns up, water is everything. If the nearest hydrant is too far away, the mains pressure is poor, or your site is rural, the Fire and Rescue Service will expect a reliable back-up supply. That is where dedicated fire water tanks come in. MJP Supplies supplies and fits fire water storage tanks across the whole of the UK, with Enduramaxx tanks as our go-to range.
What the UK guidance is really asking for
A common baseline is 45,000 litres (45 m³) of readily available firefighting water where hydrants or mains flow are not sufficient. For wet rising mains, recognised practice is two interconnected tanks (often equal size) so one can be isolated for maintenance while the other stays online.
For wet risers, the stored volume (plus any mains make-up) is typically expected to support 1,500 L/min for 45 minutes, effectively two jets running together. Tanks are normally kept full via automatic refill valves. In housing layouts, hydrant siting often works around about 90 m travel distance to a hydrant, with extra measures needed if that cannot be achieved.
New build hydrants, rural back-up water, 45,000 litre tank
On most estates, the goal is simple: firefighters can reach a hydrant quickly and get meaningful flow. Layouts are often designed so homes are within roughly 90 m of a hydrant, with private hydrants added where public ones are not close enough.
Where the site is remote, the mains is weak, or you cannot demonstrate reliable hydrant performance, that is when a static fire water tank becomes the practical route to approval. The familiar figure is 45,000 litres as a minimum reserve for developments that need an alternative supply.
MJP Supplies can provide Enduramaxx tanks as a single large store or as a twin-tank arrangement if your risk assessor or engineer wants redundancy. We also support supply-only packages for developers using their own groundworks team.
Academy sites, council buildings, community centres, fire water storage compliance
Schools and public buildings sit in a high-scrutiny zone because occupancy is high and evacuation can be complex. If the building footprint is large, or the site has limited hydrant access, it is common to be asked how firefighting water will be delivered on day one of an incident.
A 45,000 litre tank is often the cleanest way to remove doubt where mains flow is borderline, especially on older sites with under-sized incoming services. If the building design includes internal fire mains, you may also need a more resilient arrangement, such as interconnected tanks and pump provision depending on the system type.
We regularly help clients choose tank positions that keep fire service access straightforward, while staying sensible for school operations, safeguarding routes, and maintenance.
Commercial blocks, business parks, low mains pressure mitigation, on-site fire water tanks
Offices can look low-risk, but water demand rises quickly with floor area and site complexity. Larger commercial compartments and business park layouts often trigger additional hydrant expectations, and older town-centre infrastructure can struggle with flow and pressure at peak times.
If you cannot prove sufficient supply from the mains, the standard step is a static tank of at least 45,000 litres, giving the fire service a dependable drafting point. For taller buildings with internal firefighting systems, stored water and pumping may be needed to ensure the right delivery to upper floors.
MJP Supplies can advise on practical tank sizing, access for fire appliances, and whether a single tank solution is suitable or a twin-tank arrangement is a better fit for resilience and maintenance planning.
Manufacturing sites, high fire load, private hydrants, larger fire water storage
Industrial risk changes the conversation. Fire loads are higher, spaces are larger, and incidents can run for longer. Many sites need multiple hydrants on a robust on-site main, often with a looped layout for coverage and redundancy.
Where the mains cannot meet demand, 45,000 litres is the minimum baseline, but it is often only the starting point. Larger or higher-hazard operations may be pushed towards multiple tanks or a higher total stored volume, especially on rural plots or where the risk assessment anticipates sustained external firefighting streams.
We supply Enduramaxx tanks in capacities that suit phased build-outs too, so you can meet early planning conditions now and expand storage later if the final hazard profile or insurer requirements increase.
Logistics parks, sprinkler and fire service water separation
Warehouses present a familiar challenge: large floorplates and fast fire spread potential. Even with sprinklers, the fire service will want confidence that manual firefighting water is available and accessible, especially if hydrants are limited or mains flow is uncertain.
A common approach is to install a 45,000 litre static supply as the minimum contingency, then review whether additional storage is sensible based on footprint, racking arrangement, and fire load. If there are multiple systems on site, stored water may need to be managed so critical firefighting capacity remains available when it matters.
MJP Supplies can provide supply-only for contractor-led builds or full supply and fit. We will also help you think through siting: appliance access, suction connection practicality, and keeping the tank protected from vehicle impact.
Twin tanks, duty and standby, 1,500 L/min for 45 minutes
If your building needs a wet rising main, stored water becomes a core part of the design, not an optional extra. Recognised practice is two interconnected tanks feeding pumps, so you can isolate one tank for servicing without losing the firefighting supply.
The combined stored volume is typically at least 45,000 litres, designed to sustain 1,500 L/min for 45 minutes through the landing valves, with automatic refill helping maintain the level where a mains connection exists. This is about reliability under pressure, literally and figuratively.
We work with project teams to match tank configuration to the wet riser strategy, whether you need a split arrangement (two equal tanks) or a layout that suits plantroom space and access constraints.
Planning conditions, phased mains connections, interim fire water provision
Sometimes the permanent infrastructure is not ready when the risk exists. During phased developments, fire services may ask what happens if there is a serious fire before the final water upgrades or hydrant networks are commissioned.
A static tank gives you a clear, auditable answer. The 45,000 litre minimum is often the simplest interim provision because it is widely understood by design teams and enforcing bodies. On higher-risk sites, larger temporary volumes and higher delivery rates can be requested, depending on the specific hazards present.
MJP Supplies can support rapid deployment for construction phases, including supply-only options to suit contractor programmes and site logistics. If you need a temporary solution now that can be retained as part of the finished development later, we can spec for both.
Some sites step outside normal building assumptions. Fuel storage, chemical processing, and large battery energy storage installations can trigger exceptional water supply expectations because incidents can demand very high sustained flows and large volumes.
In these cases, 45,000 litres is a floor, not a target. Requirements can scale dramatically, sometimes involving multiple tanks, significant pump capability, and careful coordination with the fire authority’s preferred tactics.
If you are facing a demanding pre-application comment or an insurer-led requirement, we can help translate it into a practical tank strategy using modular storage, staged capacity, and resilient configurations, then supply Enduramaxx tanks to match.
For a wider range including many smaller tanks, please visit our full fire sprinkler water tank range.
UK Wide Fire Water Tank Supplied and Fitted
We do this nationwide, and we do it with the realities of UK approvals in mind: access, maintenance, redundancy, and making the fire service connection straightforward. If you already have a civils team, choose supply only. If you want it handled end-to-end, we can supply and fit.