Is there anything stopping me from an engineering standpoint installing a water tower on my property and making sprinklers around a radius of my home to drench the area in case of wildfire?
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Even the largest amounts of water you could reasonably store on a property isn’t really enough to create a sufficiently wide barrier around an entire home.
Some people building in wildfire-prone areas will maintain tanks/reservoirs of water and pumps, but that’s primarily for dealing with small fires that might become bigger ones.
So your question sort of has two parts. First is why aren’t homes in wildfire prone areas protected by a sprinkler system? The second part relates to a water tower.
The answer to this is sort of two fold. The first part is that typically you need water pressure to maintain the sprinklers. If the water pressure is gone, the sprinklers no longer work. And typically a lot of these places that are prone to wildfires, their water systems are pump based for their water pressure. And pumps require electricity to run. If the power goes out to the pump, no more water pressure.
Second is supply. Depending on the source of the water, that source might be required by the fire fighters to do structural loss prevention. Where they will target areas where there are high risks of structural loss. If water is being used in a non high risk area, that might be taking away water from a high risk area. For example, a wildfire that happened this year that forced me and my family to evacuate, it had forced parts of a city to evacuate. There was an order for many of the residents in the city to not waste water if they could, as the fire fighters were tapping into the local municipal water mains for water to use against the fires.
Now for the second part, a water tower. It is a hit and miss. Part of it again also has to do with water pressure. You need enough water pressure and water that it could run all your sprinklers for likely 24 hours or more. You would also have to the water tower be fairly secure against wildfires itself or you would lose the water tower and water pressure. So you have a bit of an engineering challenge there. But overall there are better solutions.
As others have mentioned, as a home owner, you want to attack the third corner of fires. And that is related to fuel. So keeping grass, plants or any potential fuel sources well away from your home. Also keeping the areas around your home well water will help. For example, just keeping your lawn well watered works well. My family had our water sprinklers going for about 18 hours really watering the lawn before the power went out. The fire only really took out parts that weren’t well watered to begin with. But we could only do that because our water source was directly from our own pump in the lake nearby.
You can also help fire proof your house, typically most structures are lost due to the fire being able to get inside, so you want to try and have the “outer shell” of the house be as fireproof as possible. So using fireproof side panelling and fireproof insulation(ie. Roxul/Rockwool). Making sure there aren’t many gaps, etc.
Why don’t you just build a moat instead. Make sure it’s wide enough that embers can’t fly across.
Interior residential sprinklers are designed to stop fires that start inside your home from a) destroying your entire house, and b) spreading to your neighbor’s house. They do nothing for wildfire.
Exterior residential sprinklers that folks typically DIY are really only effective at limiting ignitions from blowing embers. Installing non-combustible gutter guards, keeping your roof clean, and eliminating fuel sources close to the building are another way of doing the same thing.
If you’re using city water for fire prevention during a wildfire you are potentially reducing the available water for firefighters that may be trying to save someone else’s house up the road.
If there is *enough* fuel close *enough* to you that starts to burn it creates a big furnace and there is really nothing you can do. Eventually the ambient air temperature gets high enough that combustibles *inside the building* will ignite, usually curtains or furniture behind windows if the glass is still present at that point.
Also, do the math on how much water it would take to run two dozen or more sprinklers for 12+ hours. You’re looking at a very large storage tank, plus pump and power source, all protected by fire themselves and able to function totally “off grid”.
Lots are. It’s not always successful but it’s a good weapon in the arsenal. A good option as well is to remove fuel regularly, so no big trees close to the house and make sure the gutters are clean and leaf free. Another good option if you can’t do the sprinkler system is to plug the downpipes when the fire is approaching and fill the gutters with water. Hot embers getting in under the eaves and settling in the roof is a big source of fire and filling the gutters helps prevent it. Always though, once the water runs out the fire can take over. If it’s a quick fire front it might be OK, but if it’s slow, hot and there is lots of fuel to sustain it, the fire will always win.
I live in a fire prone area; this idea gets bandied about but the reality is your silly little hose and water will do nothing to stop a fast moving wildfire. These things move a football field every couple of seconds and burn HOT. What often happens is that the house is just so bombarded with embers and whipping flame that eventually it finds something to ignite. The wind is your enemy, the wind can make it so all homes in a neighborhood are destroyed or only handful.
The ways to stop your house getting destroyed are less fun than thinking you can battle a blaze with a yard sprinkler. Clear the brush from your house, use plastic decking material, finish your house with fire resistant hardy board siding, and maintain your fire breaks if you have enough property to warrant it.
In Australia the main threat is from embers getting stuck in small spaces around the home – these embers can travel up to 40km in front of the fire front.
Some companies do make sprinklers that go on the roof – but simple tasks like cleaning gutters and filling in gaps offer a great deal of mitigation.
If the firefront does reach your property, you are looking at temperatures of up to 1100 C and 100 km/h – no sprinkler system is going to be of much help in that situation.
They are used and can in fact be highly successful. Here’s one of the better “in practice” studies of the process. The tlDr is that you really want a fairly wide mist around the building envelope which helps reduce burning ember intrusion. Proper eave and vent screening is also a critical part of this process but even without that or properly managed defensible spaces the vast majority of homes with a *functional* sprinkler system survived (there are a couple that were in question as to functional.. the rest survived) this fire whereas the majority without did not.
https://wildfiretoday.com/documents/Outdoor_sprinkler_systems_effectiveness.pdf
you would also ofc want to make sure the water tower wouldn’t burn down and make sure you have sufficient pressure (possibly a propane powered booster pump)
Here’s a fun experiment: start a campfire and then start squirting water from a small water gun on it. It’s not going to make a difference. You’d need to dump a bucket of water on the fire to put it out. Now imagine flames the size of your house. How much water would you need to put it out?
You can get sprinkler systems for houses. They are quite expensive though, you need a large water source and a backup power supply.
Most houses actually survive the initial fire, they burn down later from embers in the gutters igniting the roof timbers or large burning plants that are touching the house that eventually burn through the cladding and ignite the frame. Sprinkler systems (usually misting) can help to prevent this.
Fires are actually quite rare, a particular house may only experience one every 50 years or so in fire prone areas, different areas burn each year. So a sprinkler system may not make much economic sense. Good insurance is much cheaper.
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