Why is a fire flow analysis required here?

[khu]

I'll start off by saying that I don't do much SF residential work and most of my experience is on the public side, but I'm helping someone with a new 3-lot partition. The existing parcel is on a developed street. There are streets on either end of the block with mains and hydrants and there is an existing water main running down the street that these new lots front. No hydrants on this street. The fire district said we are required to complete a fire flow analysis for the new lots and I'm a little confused since we're not proposing any new water mains or hydrants. Basically, if the builder is staying under 3600sf and we're in the 1000gpm @20psi minimum flow threshold, why are we required to do a flow test and analysis? I'm not exactly sure what we would even analyze since there are no new hydrants being proposed and the water source would be an existing hydrant at the end of the block. If they do a flow test and the existing system doesn't meet fire flow at the hydrant, I feel like there's a much bigger issue. That would mean no houses within range of that hydrant are protected, which seems like a City issue and not this builder. Any input on how to analyze this would be appreciated.

Here's a sketch of the area. It's about 360' lay length from the left hydrant to the center of the furthest new lot.

 

[1503-44]

". If they do a flow test and the existing system doesn't meet fire flow at the hydrant, I feel like there's a much bigger issue. "

Which is they will wait for that work to be done before issuing an approval to split the lot up I suppose.

 

[cvg]

well it is not up to the fire department to make sure you comply with the regulations - thats on the developer. and the insurance companies will absolutely not insure the new houses without sign off from the fire department. if everything is ok, than just do the flow test and get on with things.

 

[itsmoked]

cvg; I'm confused. The OP is being asked to do an analysis, why are you suggesting a test?

that's on the developer

Further, the OP is the developer.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[cvg]

because the fire flow analysis requires data from the hydrant test
and yes, the OP/developer is responsible for complying with regulations, what's the issue with that?

https://www.hydrant.com/fire-hydrant-flow-tests/

 

[fel3]

khu...

Does the water purveyor (whether a city, a special district, a private company) have a computer model already built so that they or you can run a fire flow simulation at the hydrant(s) nearest to the proposed development? If so, then maybe this can be used in lieu of a fire flow test. Some fire departments I have worked with will allow this, even when the water system in front of the properties already exists.

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