Firefighting water supplies and hydrants at planning stage

Firefighting water is one of the few technical items that can hold up occupation of finished houses. The condition says no dwelling shall be occupied until the hydrants have been provided, the hydrants take months to install because the water undertaker programmes them, and the developer discovers the sequence at practical completion rather than at planning stage.

The fix is boring and effective. Ask the fire and rescue service and the water undertaker what the site needs, before the application is submitted.

Why water supply appears in a planning application

Fire and rescue authorities have a duty under section 38 of the Fire and Rescue Services Act 2004 to secure an adequate supply of water for firefighting, and powers under the Act to require the water undertaker to install hydrants, with the cost falling on whoever asked for them. On a new development, that is the developer.

Building Regulations deal with the same subject from the other side. Approved Document B covers access and facilities for the fire service, including water supplies for firefighting, and sets out when fire mains are needed inside a building.

Planning sits between the two. The fire and rescue service is consulted on applications by many authorities as a non-statutory consultee, and its comments come back as a request for a condition securing hydrant provision. On a relevant building the same ground is covered in the fire statement.

None of the three regimes will design the supply for you.

Flow rates and the evidence the fire service asks for

The flow rate needed depends on what is being built. A run of two storey houses is a different proposition from a warehouse or a block of flats with a dry rising main.

Fire and rescue services in England and Wales work from the national guidance document on the provision of water for firefighting, published jointly by the local government and water industry bodies. It sets out flow rates and hydrant distribution by category of development, and it is the document the fire safety officer will be applying when they comment on your application.

What they will ask for is straightforward.

• The location of existing hydrants within and around the site, with distances
• The main size and the available flow and pressure at the proposed connection point
• The number, size and position of proposed new hydrants
• Where fire mains are proposed inside buildings, the inlet positions and the appliance standing position serving them
• For sites with no adequate mains supply, the static supply proposed and its capacity

The flow and pressure figures come from the water undertaker, not from a calculation. Ask for a flow test or a network model output at the connection point, and allow several weeks for it.

Existing hydrants and their distance from the site

Start by finding out what is already there. Hydrant records are held by the fire and rescue service and by the water undertaker, and both will provide extracts on request, often free for a development enquiry.

The plan you produce should show every hydrant within a sensible radius, with its distance from the furthest point of the proposed development measured along the route an appliance and crew would take. Straight line distances across a site that will have fences on it are misleading.

Two common findings. The existing hydrant is on a main too small to deliver the flow the development needs, so a new main is required rather than a new hydrant. Or the hydrant exists on record and has been surfaced over during previous highway works, which only comes to light when someone lifts the cover.

Where an existing hydrant is being relied on, say so explicitly and give its reference number. A condition can then be discharged by reference to it rather than by installing something unnecessary.

New hydrants and who installs them

Hydrants on the public mains are installed by the water undertaker. The developer requests and pays. That is the practical position on almost every scheme, and it means three things for the programme.

The undertaker's timescale is theirs, not yours, and it is measured in months rather than weeks on anything requiring a main extension.

New mains within the site are usually laid under a self-lay agreement or a requisition under the Water Industry Act 1991, and the hydrants go in with them. Coordinating the hydrant positions with the fire and rescue service before the main is laid avoids a second excavation.

And private hydrants on private roads are possible, but they come with a maintenance obligation that has to sit somewhere. A management company that does not know it owns three hydrants will not be testing them.

Utility capacity generally is worth resolving in one exercise rather than in five. A Utilities Assessment covers water, foul, power, gas and telecoms enquiries together, and the water flow test can be requested alongside the potable supply enquiry.

Static supplies on rural and constrained sites

Where the mains cannot deliver, the answer is a static supply: a tank, a pond, a reservoir or an accessible watercourse with a hard standing for an appliance to draft from.

Design points that come up repeatedly.

The supply needs a capacity agreed with the fire and rescue service, and a way for an appliance to draw from it, which means a hard standing within suction lift distance and a suction point that does not silt up.

A pond used as a firefighting supply has to hold its level in summer, which is exactly when it is least likely to.

A tank has to be maintained and refilled, and the obligation has to be secured. On a scheme of any size that usually means a section 106 obligation or a management company duty rather than a planning condition alone.

An illustrative sequence. A rural scheme of eight dwellings finds the nearest hydrant 400 metres away on a 90 mm main. The undertaker's flow test shows the flow is inadequate. The options are a 300 metre main extension at the developer's cost, or a 45,000 litre underground tank with a draft point beside the turning head. The tank costs less to install and carries a maintenance liability for the life of the development. Both are viable, and the choice needs making before the layout is fixed, because the tank needs space and access.

Conditions and obligations securing provision

Expect a condition along these lines: no dwelling shall be occupied until fire hydrants have been provided in accordance with details first submitted to and approved in writing by the local planning authority, in consultation with the fire and rescue service.

Three things make that condition survivable.

Submit the hydrant details with the application, so the condition can reference the approved drawing rather than requiring a fresh submission.

Ask for the trigger to be phased on a scheme built in phases, so that hydrants serving phase one do not have to wait for phase three.

And start the undertaker's process at the point permission is granted, not at the point the condition is discharged.

Where the site includes a relevant building, the water supply position belongs in the Fire Statement alongside appliance access and the evacuation strategy. Fire statements legally require an author with the necessary fire engineering competence, and a PlanScope draft is a starting point for that professional rather than a substitute.

PlanScope drafts fire and utilities planning documents structured to UK planning policy, with a "to be confirmed" flag wherever undertaker or fire service information is missing. This is general guidance, not legal advice. Check the position with your local planning authority or a qualified professional before relying on it. Browse the report types and start a draft.

PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.