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new water line

I am running a new water line from a county main to a 1 bath mobil. The line needs to be ran about 1400 feet. What size pipe should I use to have the best water pressure. I will be having 2 outside faucets.

Re: new water line

Based on your description of the home, a 3/4" water supply should be adequate but a 1” line is more common for a main supply, although 1-1/4” isn’t uncommon. This is normally something you need to work out with your water supply company. Home elevations and supply ratios tend to lend unexpected variables into supply line size. Neither of which you’ve supplied.

So, to keep a simple question simple… A 1” standard supply line is far more than adequate for what you’ve described provided your home is at a level elevation with your supply and your supply is at a constant pressure and not based on an above grade holding tank (common in mountain areas) and not based on anything else that’s considered uncommon.

Re: new water line

There are a lot of factors that you need to know to size a water line. (pipe size, pipe length, pipe type, flow rate, main line pressure) You should contact your water department and have them help you properly size your water line.

A 1400 foot long 1" poly line with a 10 gpm flow would have a pressure drop of about 42 psi. 1-1/4" would lose 14 psi, and 1-1/2 would lose 6 psi.

Re: new water line

Based on Blake's advice, I'd err on the side of caution and go bigger if you can afford it. If you eventually add other features, such as a guest house, shop, sauna, etc. you won't need to replace it. If there's any chance of any houses being added to your 1400' of road, then that should be a consideration in sizing the pipe.

I've seen some people install two water lines; one is a spare in case the first one is damaged. Of course that doesn't make a lot of sense if they are buried right next to each other.

Re: new water line

Blake makes alot of good points. Many things to consider. Be careful With water lines that long parasitic drag needs to be figured in. Pressure loss Is the main factor here. I personally would never run a water line that long smaller than 2". If you have ever seen a water main tap made you would be surprised how small a hole is actually drilled.

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