1400 foot water line in hill country TX

[TX Hill Country]

I've seen a few posts about long supply runs from water meter to house, however I haven't seen (or found online) any generic calculator or table that applies.

My situation - Water meter is available at top or bottom of property which is about 2000 feet deep, with 140 feet elevation drop from top to bottom.

I want to properly size and select the recommended water supply line, which I'll likely trench and install myself, along with irrigation (drip irrigation will be a topic for the future, I'm aware of the challenges)

I assume it's best to use the meter at the top. I'm not sure yet what size, if it's < 1" I'll need to upgrade it most likely. Future 5000sf house and 3000sf shop will be built (10 acre property). House not designed so I need to make best guess for now, I'll err on the size of more capacity (gallons/minute) rather than less.

Supply run:

Meter -> 70' elevation drop over first 800 feet, then 10' drop for next 600 feet to where the house will be located. 1400' total.

Bringing water from the bottom of land would be a shorter distance, about 600 feet, but the elavation increases 60' and I think that's a problem.

Looking for suggestions about

a) type of supply line and size. Price is not a huge concern, but minimizing leaks and ensuring sufficient flow is

b) any need for pressure reducing along the way. Maybe the supply line can tolerate increases on the downward slope and normal pressure drop per length of supply line will help reduce the pressure.

A reference to a table or calculator would be great since I also will need to run the irrigation, probably in the same trench, and I imagine that will need careful design and layout. The irrigation will be a combo of drip and spray heads. In the future I might put in a well for irrigation on the flat areas closer to the house.

 

[Reach4]

I assume it's best to use the meter at the top.

Meter closer to the house means you are not paying for water that gets spilled on the way to the house due to a failure.

I assume it's best to use the meter at the top. I'm not sure yet what size, if it's < 1" I'll need to upgrade it most likely.

It is common to have a smaller nominal meter size than pipe size. For example, a 5/8 meter with 1 inch pipe is not bad. I think 3/4 is enough for most houses, but I don't know how much load you want city water to be used for irrigation.

Pressure Drop Calculator (use 0.03 mm?) is a nice pressure drop calculator.

See https://terrylove.com/forums/index....sure-need-advice-on-piping.92695/#post-668114

 

[Sponsor]

 

[Jeff H Young]

there is no pressure drop when you're not running water so you would have about 35 more psi 70 foot lower add that to static pressure at meter just throw a number 80 psi and you would be at 115 psi no idea what actual pressure is but adding 35 psi will dictate the requirement working pressure required. Likely a PRV be required upon the entry of home and work shop perhaps 1 each.
Polyethylene a common choice

 

[Jeff H Young]

5000 foot house a little bigger than the average crib . I'd be going bigger than 3/4.

 

[wwhitney]

I find this pressure drop calculator easier to use:

http://irrigation.wsu.edu/Content/Calculators/General/Pipeline-Pressure-Loss.php

Note that you need the actual ID of the pipe you're going to use--there are wide variations in ID among different pipe types that are all nominally called 1". And I assume at the distances involved, you're looking pipes in the 1" to 2" range.

2.31' of water column = 1 psi, so you're either looking at a 35 psi rise from the water main pressure at the top of your property, or a 26 psi drop from the water main pressure at the bottom of your property.

I would think the first question is what water pressure will the utility provide (both typical and minimum) at each location? If they'll only provide 50 psi at the bottom, then 24 psi would be rather low at your house, so that would not be a good option. If they'll provide 80 psi, then 56 psi is quite reasonable.

Cheers, Wayne

 

[TX Hill Country]

there is no pressure drop when your not running water so you would have about 35 more psi 70 foot lower add that to static pressure at meter just throw a number 80 psi and you would be at 115 psi no idea what actual pressure is but adding 35 psi will dictate the requirement working pressure required. Likely a PRV be required upon the entry of home and work shop perhaps 1 each.
Polyethelene a common choice

Thanks, that helps - In my area I think city water is often around 60PSI but I really don't know at this property, but I'll keep that in mind.

So PRVs will required at the entrance to the home and shop, which makes sense because the pressure gain from the elevation drop will be always be present, and only at times of high flow (eg: 10 gpm) will there be a reduction due to supply line friction. Sounds like PRVs are in my future!

 

[TX Hill Country]

I find this pressure drop calculator easier to use:

http://irrigation.wsu.edu/Content/Calculators/General/Pipeline-Pressure-Loss.php

Note that you need the actual ID of the pipe you're going to use--there are wide variations in ID among different pipe types that are all nominally called 1". And I assume at the distances involved, you're looking pipes in the 1" to 2" range.

2.31' of water column = 1 psi, so you're either looking at a 35 psi rise from the water main pressure at the top of your property, or a 26 psi drop from the water main pressure at the bottom of your property.

I would think the first question is what water pressure will the utility provide (both typical and minimum) at each location? If they'll only provide 50 psi at the bottom, then 24 psi would be rather low at your house, so that would not be a good option. If they'll provide 80 psi, then 56 psi is quite reasonable.

Cheers, Wayne

thanks, that calculator looks perfect. And also your comment about not entirely ruling out the shorter run from the bottom end of the property. I've assumed it will be 60 psi, but I really don't know. I'm in favor of having too much pressure vs insufficient pressure, with the knowledge that there will be costs (for PRVs) at the house, shop and then for the irrigation that's a different situation I'll ask about in the future.

Other than cost is there any problem with oversizing the supply line? Meaning for example a 2" line even if a 1" or 1.5" would suffice?

 

[Terry]

Here are the type of charts I use for sizing water for a home.

A standard one-bath home with kitchen sink, dishwasher, water heater, clothes-washer, 1.6 tank toilet, lavatory, tub/shower combo and two hose bibs would be counted as 18 fixture units.

Most standard two bath homes consisting of kitchen sink, dishwasher, water heater, clothes-washer, two 1.6 tank toilet, two lavatories, one shower, one tub/shower combo, and two hose bibs would be counted as 23.5 fixture units.

Most standard three bath homes consisting of kitchen sink, dishwasher, water heater, clothes-washer, three 1.6 tank toilet, four lavatories, two showers, one tub/shower combo, one whirlpool bath and two hose bibs would be counted as 34 fixture units.

 

[Jeff H Young]

wayne brought up good points if pressure is high enough at the lower elevation . a savings of 800 ft of trenching labor and material is significant. Id want to know if its safe to trust the pressure remains strong for future years to come and would seek answers from water provider . Dont see why a 2 inch line would hurt it might even need bigger. what is it like 6 or 7 baths plus a shop with needs?

 

[TX Hill Country]

wayne brought up good points if pressure is high enough at the lower elevation . a savings of 800 ft of trenching labor and material is significant. Id want to know if its safe to trust the pressure remains strong for future years to come and would seek answers from water provider . Dont see why a 2 inch line would hurt it might even need bigger. what is it like 6 or 7 baths plus a shop with needs?

I don't know that I'd trust any answer from the water provider, I imagine it depends on their infrastructure but you're probably right that I should ask.

For the trenching I don't know if I'll really save anything because I plan to trench end of end of the driveway for accessible irrigation anyway. Despite the deep freeze in TX last week I don't think I need to really bury the line much deeper than 12" anyway, so I plan to combine the water supply line and the irrigation in the same ditch unless somebody tells me that's a really bad idea. In a subdivision I'd think it would be, but this is a ranch where if someone is working on the irrigation system with equipment and they hit the water line, we'll just fix it. So ultimately the tradeoff here is cost either way, and I'm assuming that PRVs will be cheaper than maintaining a booster pump around the house/shop to supply water uphill to the top of the property for irrigation.

 

[Reach4]

I'm assuming that PRVs will be cheaper than maintaining a booster pump around the house/shop to supply water uphill to the top of the property for irrigation.

A PRV would be much nicer than a booster pump.

I would have a boiler drain valve on the upstream side of the PRV. You could mount a garden hose thread pressure gauge on there when you want to take a pressure reading.

Some PRVs have a screen. If yours doesn't, you would probably want to put a wye filter before your PRV.

You may want to put some wire in the trench for handy outlets. You would want a switch for the outlets at the house.

 

[TX Hill Country]

A PRV would be much nicer than a booster pump.

I would have a boiler drain valve on the upstream side of the PRV. You could mount a garden hose thread pressure gauge on there when you want to take a pressure reading.

Some PRVs have a screen. If yours doesn't, you would probably want to put a wye filter before your PRV.

You may want to put some wire in the trench for handy outlets. You would want a switch for the outlets at the house.

thanks for the confirmation! I'll keep your points in mind for pressure readings and filter.
The electrical is a different question, when I've looked at the voltage drop for a simple 15A line the wire size is huge, so I've started looking at whether I can use transformers to go from 220->440->110 with the 440V run being the longest sections. Have had a few conversations with some electricians and didn't get a confident answer yet about the best approach.

 

[Reach4]

The electrical is a different question, when I've looked at the voltage drop for a simple 15A line the wire size is huge, so I've started looking at whether I can use transformers to go from 220->440->110 with the 440V run being the longest sections. Have had a few conversations with some electricians and didn't get a confident answer yet about the best approach.

How far are you planning to run, and can you reduce the required current?

AFAIK, you don't have to size the wire to keep the voltage drop under 10% at 15 amps just because you use a 15 amp breaker. If you are running some LED lights, you might get by with 10 AWG with a 15 amp breaker but driving 3 amps of lights a long way up the hill. I could be wrong on that, but I think the breaker is to protect the wire.

What kind of load are you talking about? Utility outlet for who-knows-what?

 

[TX Hill Country]

How far are you planning to run, and can you reduce the required current?

AFAIK, you don't have to size the wire to keep the voltage drop under 10% at 15 amps just because you use a 15 amp breaker. If you are running some LED lights, you might get by with 10 AWG with a 15 amp breaker but driving 3 amps of lights a long way up the hill. I could be wrong on that, but I think the breaker is to protect the wire.

What kind of load are you talking about? Utility outlet for who-knows-what?

The most important would be operating gates at either end of the property. Next (and also important) will be lighting, certainly led. Probably just minimal landscape lighting for safety and looks. After that, having power could be handy for running tools, and that's wide open.

So yes the current could be minimal and I might well be able to get away with just a few amps, but if there's a way to get more without breaking the bank too much I'd do it for flexibility.

To a large part this is just an interesting curiosity for me - I know that I can get solar powered gates, and solar powered lights, but if I can have standard electric I'd prefer it.

 

[wwhitney]

AFAIK, you don't have to size the wire to keep the voltage drop under 10% at 15 amps just because you use a 15 amp breaker.

That's correct, voltage drop should be calculated based on the expected load, not the ampacity. Of course, if you want to be able to plug in a 15 amp load 600 feet away, you have to use those numbers. But LED lights or a 12V gate opener with battery and battery charger wouldn't draw that much.

Since you're running water lines in the trench, you could just run a decent size PVC conduit, like 2". Then it's ready for you when you need it and can pull wires in. You might just have to dig to find it and intercept it where you need power so you can bring it up to grade (all before pulling wires). Or if you know the locations ahead of time, you can turn the conduit up at those locations into a quartzite box.

Cheers, Wayne