Fire Hydrant colours and painting

[Sources for this page]

The Water Supplies Department released the guidelines for painting hydrants on their website. Look for WSD 1.34 - Painting on Fire Hydrant. You can check it out if you are interested in the technical specifications.

Here are the important points:

• Serial numbers are to be painted on the hydrants
• A 50mm wide, 93.3mm long ⮜ V-shaped arrow head should be painted on the hydrant and point towards the surface box (which houses the hydrant control valve)
• If the surface box is more than three metres away from the hydrant, the distance (in metres, rounded to one decimal place) should be painted next to the ⮜ V-shaped arrow head. If the surface box is within three metres, then the distance should not be painted.
• Fire hydrants that use fresh water should have its body painted red, with yellow markings
• Fire hydrants that use seawater should have its body painted yellow, with red markings
• The cap of a Swan Neck and the front cap of "pedestal" hydrants should be painted blue if they are installed but not yet in service
• If the hydrant is connected to a trunk main, a white band should be painted on the hydrant body

If you are thinking, some of these points don't seem to line up with what we see on hydrants today, and that some things are missing...well, WSD 1.34 was first released on Y1995-M11-D20, and the most recent revision was on Y2003-M09-D05, more than two decades ago. I will list out all the differences I noticed.

Hydrants painted in colours not mentioned in WSD 1.34 - green and teal

In slop posts and articles, green hydrants are said to use processed waste water, but I am yet to find official sources to back this up. I don't think there is any publicly available official source that stipulated the use of green paint (or any other paint that isn't red or yellow) for hydrants using any other water type. So, how did those posts and articles know green hydrants use processed waste water? Only they will know, I suppose. Anyway, I am only aware of Round Heads painted in green, more details in this page.

As for teal, I don't think there are any discussions regarding the water type it uses, but some social media posts seem to have considered these as being the same as green hydrants. It is possible that teal and green hydrants use the same type of water as some green Round Heads at the Fire and Ambulance Services Academy were repainted teal. But again, no idea what water teal hydrants uses. And again, I am only aware of Round Heads painted in teal, more details here.

Hydrants painted in colours not mentioned in WSD 1.34 - lavender

In online discussions about lavender Round Heads in the North District, some netizens suggested that hydrants painted lavender use reclaimed water. While WSD 1.34 doesn't mention lavender, these netizens might be correct. Reclaimed water is a type of recycled water, and a Water Supplies Department document about recycled water stipulated that recycled water pipes should be purple or lavender. The Shek Wu Hui water reclamation plant in the North District entered service in 2024, and the Water Supplies Department began providing reclaimed water in Sheung Shui and Fanling for toilet flushing in the same year. The water reclamation plant is literally on the other side of the road from the San Wan Road × San Po Street lavender Round Head (no hydrant at that location before). With all these facts in mind, I think it is reasonable to assume that hydrants painted lavender use reclaimed water.

However, when some official sources (such as news.gov.hk) and news media talk about reclaimed water usage, they usually mention toilet flushing, road cleaning, and park irrigation prominently, neglecting other possible usages. This lead to some news media incorrectly claiming that these lavender hydrants will not be used for firefighting. This is a really ridiculous claim, why would the Water Supplies Department and/or Fire Services Department went to the trouble of installing these hydrants if they do not intend to use it for firefighting? Those taps we see in parks and on pedestrian footpaths will be sufficient for road cleaning and irrigation. Besides, fire hydrant have to be tested regularly (for things like water pressure) to ensure their effectiveness in case of fires. Installing fire hydrant for road cleaning or irrigation is just overkill and wasteful of resources. And you need special tools to use a fire hydrants (such as a hydrant key), this is to prevent hydrants from being misused. Of course, I am not saying fire hydrants will never be used for non-firefighting purposes, I have seen small work sites (such as waterworks, drainage works, and footbridge lift construction) use water from fire hydrants by connecting a hose to the hydrant. But at the end of the day, firefighting is the main purposes of fire hydrants. In the Drainage Services Department and GovHK webpages about reclaimed water, firefighting is clearly stated as one of the ways to use reclaimed water. All I want to say with this wall of text is that, if the departments installed a fire hydrant, then its main purpose is to fight fires, it is silly to suggest otherwise. If you want to find lavender hydrants that are yet to be discovered in the North District, you can check out roads where reclaimed water pipes are laid. You can find a map showing the proposed reclaimed water pipe network at the Water Supplies Department webpage about the "Reclaimed Water Supply to Sheung Shui and Fanling" project. Note that this map may not show all the reclaimed water pipes as it is likely an early draft. In fact, the map does not show reclaimed water pipes at the locations of all three known lavender Round Heads mentioned in the Round Head page. I believe the project scope was expanded at some point to cover these areas but the draft map was never updated. I am not sure about the type of water used by lavender Round Heads in Hong Kong Disneyland though, I can't find any water processing plant near Disneyland on maps.

Hydrants painted in colours not mentioned in WSD 1.34 - silver

If you search for "silver hydrants" online, you will likely find slop claiming that new hydrants not yet in service will be painted silver. But again, WSD 1.34 didn't stipulate that. I believe the actual reason for the silver colour is that it is the colour of the primer coating, there are primers that appear silver. I believe these hydrants are not intentionally painted silver because of any guideline or requirement, but simply a need to apply some sort of coating to prevent rust and make application of actual paint easier. From what I know, primer is not meant to be a permanent type of coating so you would expect actual paint be applied as soon as possible, which means it is hard to find hydrants painted primer silver. But as mentioned in the Round Head page, there are several Round Heads in the North District that have had their primer coating for months.

Hydrants painted in colours not mentioned in WSD 1.34 - grey

I believe grey is another primer used on hydrants, which can be seen if you are lucky, or if the upper layer paint of a painted hydrant faded away. Some people online call this colour white, but I will call this primer grey to avoid confusion with the white bands which I will discuss later in this page (also, compared to the white band, the colour of this primer is not as white).

There was actually a historic precedent for painting hydrants grey when they have been installed but not yet in service. On Y1964-M04-D03, the Water Authority (Water Supplies Department didn't exist at that time) sent a memo to the director of Fire Services regarding five fire hydrants numbered 567 to 571, which had been installed and were being fed by a pumping station without continuous supply outside pumping period at the time. These hydrants must be installed before continuous supply was available because the installation had to happen when the road was being reconstructed. What the Water Authority did was to paint 567 to 571 grey to differentiate them from other fresh water and salt water hydrants. They would be repainted red when a reliable source of fresh water was expected to be available by the end of 1964. However, I am not sure if the shade of grey used in 1964 is the same as the primer grey we see today, and the 1964 memo also did not mention if the temporary grey was actual paint or just a primer coating.

Hydrants painted in colours not mentioned in WSD 1.34 - black

I only managed to find one fire hydrant painted black: the Swan Neck-like private fire hydrant at the Lutheran Theological Seminary. I have no idea why they painted it black.

Painting caps blue

WSD 1.34 said to paint just the front cap of a hydrant, and only when it is newly installed. But nowadays, we often see hydrants with all caps painted blue, not just the front cap. Also, it seems painting caps blue has evolved to mean that a hydrant is out of service temporarily, regardless of whether it is new or old. For example, the Swan Neck previously numbered 69 (now it is numbered 30249) had its cap painted blue for a few years when it was obstructed and couldn't be used due to some construction behind it, but it had already existed for years before its cap was temporarily painted blue.

Another example is "Octagonal hydrant" 30089 (previously 134), which had all its caps painted blue at some point between Y2016-M12 and Y2020-M10. Google Map street view's earliest capture in Y2009-M01 showed this hydrant, and we know "Octagonal hydrant" is an old hydrant type so it is very likely to have existed for a few decades before that. It is as "not newly installed" as you can get. And of course, there is the Heavy Draw-off hydrant 30499 (previously 3), with all twelve of its caps painted blue despite the Heavy Draw-off hydrant type being a product of the 1960s~1970s.

Last but not least, there is an interesting Round Head, which was painted red but there is only a small patch of blue spray-painted on the top of it. It did not exist in the most recent 2024 Google Maps street view capture so it is definitely new, in fact it does not even show up in GeoInfo Map. This definitely does not comply with neither the WSD 1.34 requirements nor the modern practices. Seriously, just how hard is it to spray-paint the front cap...

The white band

The wording is slightly different between official sources, with WSD 1.34 saying "connected to a trunk main" and the Fire Services Department's street hydrant testing and commissioning checklist saying "fed directly from government trunk main". Sometimes you see online slop claim that hydrants with white band means they can be used even during water rationing periods. I don't know enough about waterworks to say if connected to trunk main / government trunk main = no water restriction during rationing periods. There was at least one mention of trunk mains being "charged 24 hours" in old Fire Services and Water Authority documents though.

If the white bands are really for identifying hydrants during water rationing periods, then it would mean there is no need to paint white bands on hydrants as water rationing are not likely to happen in the future (fingers crossed). But then, we have some relatively new hydrants painted with white bands, such as the FH prefix Round Heads in West Kowloon Art Park.

Even though WSD 1.34 only showed examples of how the white band can be applied to Round Head and Swan Neck, I haven't seen a Swan Neck with white band yet. There were photos of some red Heavy Draw-off hydrants having white bands in the past, but you can't see white bands on these hydrants in 2026 anymore.

The big numbers painted on the hydrants now are not serial numbers

If those are serial numbers, then each number should be unique to each hydrant, but that is not the case. There are many cases of hydrants sharing numbers. More details on hydrant numbers in this page.

Non-standard hydrant markings colour

Even though WSD 1.34 stipulated yellow markings for red hydrants, it is not uncommon to see white markings on red hydrants. While technically non-standard, it is not that big of an issue. But how about something more radical...like black? For some reason, the red Round Heads at Riviera Gardens housing estate have black markings. To top it all off, there is no ⮜ arrow head on top of the hydrant, they just repeated hydrant number and painted that on top (pun very much intended).