Water storage tank for firefighting

[ltlredwagon]

Well, I really don't know if this forum is open to homeowners. Seems like this site is for fire professionals. But I'll throw this out.

I'm in a mountain area of southern California. I have two cabins (1500 sq. feet total) on 5 acres, small orchard, surrounded by national forest. Southern boundary of my property is a year-round stream with substantial flow (10000 gal./min). My property runs from about 5000 ft. elevation to 5200. My thought was to put a 10000 gallon tank on the hill and use gravity to run an irrigation system for the orchard, and for firefighting, both a dedicated fire hydrant if needed, and a sprinkler system which I can set off if I have to evacuate in the event of a forest fire. So I am trying to decide what type of water tank would be best, and what type of pipe to use. I'll need to run the pipe from the tank on the hill down the hill about 500 feet. I can bury the pipe somewhat, but the terrain is very rocky, so it would be hard to get it deep. I'm looking for the least expensive way to have a tank and pipe system which doesn't fail during a forest fire. Would appreciate direction to good sources of information.

[PaladinKnight]

Perhaps this may help:

http://cee.eng.usf.edu/peacecorps/images/Technical%20Briefs/9%20-%20Visualizing%20Construction%20of%20a%20Gravity-Fed%20Water%20Supply%20System.pdf

I recommend this book:

“A Handbook of Gravity-Flow Water Systems” : Thomas Jordan


This will provide more data and information than you are requesting, but it is the principals that I am pointing you to.

[Rescue101]

You MAY want to think BIGGER that 10K. Doesn't last long in active FFing and more is better. T.C.

[tree68]

If you can pull it off, you might consider a "hydraulic ram" (Rife was one brand, there are/were others) to keep your tank topped off. It's gravity operated and will pump up to 10 times the available head (ie, 10' head will pump up to 100' of elevation).

It uses no outside power and runs as long as there is water feeding it. If you can harness any of the flow of that stream, you'll be all set.

A web search will provide plenty of info for you, possibly including info on how to build one from scratch.

As for the piping - plastic may be the cheapest and easiest to work with, but it'll melt in a fire unless you get it underground. You must consider the desired flow. Watering a garden doesn't take much volume, but firefighting, or even a protective sprinkler system, will require a lot more than a 1" pipe coming out of the storage tank.

[Catch22]

You MAY want to think BIGGER that 10K. Doesn't last long in active FFing and more is better. T.C.

I was thinking the same thing. ISO uses 30K increments for it's rating, which is something I think I'd take into consideration and make sure to discuss with my homeowners insurance agent.

[fire49]

Suggest you post here

http://www.inspectpa.com/phpbb/forumdisplay.php?17-Commercial-Fire-Codes

Also contact the local tie dept for advice and what will work for them


Also not sure if you are installing sprinkler system or a company but if company they can be a help

[fire49]

Forgot about calif forestry you might contact them for guidance

http://firecenter.berkeley.edu/docs/CE_homelandscaping.PDF

Not sure what above ground system would hold up to fire except concrete

[fire49]

http://buttecounty.net/Fire/Fire%20Prevention/~/media/County%20Files/Fire/Public%20Internet/Prot%20Plan/Fire%20Flow%20Requirements%20060409%20%20TRAKIT.ashx

http://www.fire.lacounty.gov/Forestry/RoadMaptoFireSafety.pdf

[ltlredwagon]

Thanks very much to all. This is very helpful. I've ordered the book and printed out the references.

It also occurred to me (again, I'm a newbie, don't know if this is wise or has been done) that if I could effectively seal a propane tank and generator in a concrete box and bury pipe from a stream intake to the cabins, perhaps I could (at far less expense) set up a system where I could, in an emergency, turn on a sprinker system powered by the generator pumping an "endless supply" of water from the stream.

Anyway, thanks again and I'll follow up on your advices.

[CdnFD24]

I agree with the idea of a hydraulic ram to keep the flow going. As well as protecting your tank with concrete.

I would recommend not containing your generator with the tank in concrete. The small engine may fail if the fire impinges on your concrete structure, especially where the fresh air intake is for your engine.

It would be best to have your generator (I'm assuming this is to feed power to a pump to boost the sprinkler system as well as a waterpump for firefighting?) located with the structure you are protecting.

[rescueraver]

First is your property defensable keeping all brush cleared is the key to protection, no fuel no fire. Can a four wheel drive fire truck access this 10,000 gpm stream if so the they can protect your property. Have you looked into a home foam system spray and go. As for your sprinkler system you need to talk to a fire protection engineer. A above ground system would have to be in steel. You could use plastic but you would have to cover the pipe with dirt for thermal protection in areas you couldnt bury it.

[Catch22]

Some more information you can use to help protect your home/property....

http://www.firewise.org/

[ltlredwagon]

Again, thanks very much for the information and advice.

The ram sounds great. I have two possible locations for a water storage tank - one at 100 ft higher than the cabins and another at 180 feet higher. Upstream from me is national forest, and I only have 250 ft stream frontage with only 10 ft of head, so RAM might not work.

Propane tank in concrete and generator and pump near cabins - yes, that sounds much better.

Defensible space - yes, I'm working on that and CalFire is coming in a week to look. They have program where they pay 75% and homeowner pays 25%.

I'm in a mountain valley, 1/2 mile down dirt road. 20 min travel time for fire trucks, but only a few homeowners where I am so we would not be a priority in a wildfire. I need to be 200% prepared. Fire trucks could get here though - as close as 200 ft from stream.

[PaladinKnight]

I would think about a plan B, if all else fails.

You state that a fire truck can only get as close as 200' from the stream. As a backup plan, in the event that you run out of water, lose the ability to power the pump, etc... install a dry hydrant where a truck can access it. This will mean bringing the plumbing (pipe), from the stream, 200' to a standpipe that they can draft from. If the pipe depth remains below the highest level of the stream, it will hold water. When the fire engine hooks in, they only need to backfill the void between the water level and reverse to draft, or use their primer on the pump. This will depend on the pump system.

You may be able to combine the plumbing with the supply to your pump and storage.

Another thought, you will need around 50-55psi for your sprinkler system. Unless you have a substantial elevation and quantity for your water storage, you will not be close to that. Static pressure may be around 30 to 32 psi. Example: At about 75 feet to the highest level of water maintained, say about 20,000 gallons, you might get close to 42 psi. The books will show the formulas to calculate the static pressure of the water column, basically the pressure in the pipe.

System wise, I would pump to the storage tank, then let gravity flow to the wet barrell hydrants, and on the same line, supply the sprinkler system and perhaps the house water supply. It could all be shared. The trick will be reaching the residual pressures that will be required if everything hits the fan. Once high flows begin, the water supply will change, as will the weight and pressure of the supply. This is why I suggest a Plan B, in the event a prolonged event should wipe out your supply and pumping capability.

Think of this system as your own municipal water supply. You are the provider and customer. This design is in place across the planet. If you add your filtering system then you can drink it. This is of course an ongoing expense, but not as burdening as you would think. After all, there is just you.

I suggest building a pump house with the back-up power very near, perhaps below ground in the same building. I have seen several of these built over the years along this method. 10,000 gallons will not last long during a fire, so I would think bigger. The ability to recharge the supply will determine the capability. I would not rely on pumping from the stream to the sprinklers, but concentrate on recharging the tower or tank. If your pumping capability should fail, then you're done without an elevated water supply.

More than anything else, the cost of the system will be your driving factor. of course you have to build what you can afford. But you also should measure this against the value of what you are trying to protect. So, do not cut corners that may hurt you down the road.

Just a few suggestions.

[ltlredwagon]

Thanks Paladin. Exellent recommendations. With a tank at 180 feet up I think I can get the needed water pressure but I'll get some engineering help on this. I'll move ahead. Thanks again.