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Hi,
I have recently moved to a farmhouse in central Scotland and the other day our closest neighbour accidentally burst our water main with a JCB. The main is a 1” MDPE pipe running about 500m from the water company roadside main to our farmhouse. This was installed about 20 years ago. The farmhouse is perhaps 5-6m lower than the point it connects to the water company main but our house is on two floors so the upper floor is around 3m above ground level. We have a ground source heat pump with unvented cylinder so we can’t use a shower pump and our water tank is downstairs.

My neighbour, who is a builder and architect has decided to take a branch from my pipe while doing the repair, so that he can feed a house that he is refurbishing. His branch is coming from an equal T piece so is also 1”. He says it should not affect my pressure/flow because you can feed 3 houses from a 1” pipe.

So, my question is, should I be concerned about this or am I worrying about nothing? His branch point is around 80m from the roadside mains supply and my house is around another 500m downstream and like I said 5-6m lower than his house.

Obviously I don’t want to fall out with my neighbour having only just met, but it’s going to be much more awkward if every time someone turns on a tap at his house my supply stops!

Advice most welcome!
Thanks,
Craig.
 
Did he ask your permission first and tbh I would tell him to get his own supply

Will effect your flow and pressure

Let’s say you had 3 bar and 20lpm

When both of you run off best outcome would be 1.5 bar and 10 lpm will be worse as he’s first so will get most of the flow
 
Before you act check the legal side. If your main comes across his land a term of the easement might give him rights that you have not considered, check your deeds is my advice. centralheatking
 
As CHK above wherever the supply runs check if there an easement agreement, if it's on the neighbours land or shared access land.
Unless the neighbour already had connection to your supply I doubt they also have a right of connection .

You Builder neighbour knew exactly what he was doing, that was no accident.
He's saving several thousand pounds on a new connection and excavation to the main.
Over that distance, no the supply won't be adequate for more than 1 property.

Are you on a Water meter, if so is it in the house or in the Street /road ?
 
Hi guys, thanks for the prompt response. Definitely some good advice to consider.

Firstly, no he did not ask for permission but yes the pipe does currently go through his land although there is nothing on the title deeds to show this. To complicate matters a bit, I haven't actually bought the house yet due to other title deed issues but we are living here with the permission of the owner while he sorts out the deeds.

It's possible the builder did do this on purpose although the circumstances suggest it was an accident as he was digging a new road in and was trying to remove a tree stump when he hit the main. But I hear what you're saying and you could be right. I've only really known the guy for a week or so.

We are not on a water meter as far as I am aware but will check.

Thanks again for your advice - I'll talk to the current owner of our house because this needs to be sorted out before we buy the house I think.
 
Builder & Architect - combined !
Not sure if that would double the BS or inversely square it.

I would tell him that your pressure and flow has been severely depleted at times and you want the connection removed.
 
@oz-plumber the trouble is, he hasn't started the house renovation yet so there is no demand being placed on the branch he took. He expects the renovation to take about 6 months and then he'll be selling the house on. So the first time we'll really know what effect this has is when the new owners move in and start consuming water by which time the pipes will all be covered over etc. What I could do is conduct pressure/flow tests with his branch closed and open and see quantitatively what effect it has. I have no doubt it will have an effect, the question is just how bad will it be.
 
the pipe does currently go through his land although there is nothing on the title deeds to show this. To complicate matters a bit, I haven't actually bought the house yet due to other title deed issues but we are living here with the permission of the owner while he sorts out the deeds.
You need to discuss the position with whoever is doing the conveyancing for your purchase. In particular, you need the easements (or whatever the Scottish equivalent is) that guarantee your water, electricity, gas, drainage, passage across any land you won't own outright. The fact that there are "title deeds issues" is, IMO, a big red warning flag for the property. Low water pressure could be the least of your problems once you actually own it.
 
You need to discuss the position with whoever is doing the conveyancing for your purchase. In particular, you need the easements (or whatever the Scottish equivalent is) that guarantee your water, electricity, gas, drainage, passage across any land you won't own outright. The fact that there are "title deeds issues" is, IMO, a big red warning flag for the property. Low water pressure could be the least of your problems once you actually own it.

Yes we'll be making sure this is all taken care of but thanks for the warning. The main issues with the title deeds arise from movement of boundaries with consent of the neighbouring landowner but this all needed to be documented properly. There were also some issues with land that had been inherited from parents many years ago but the documents had gone missing. They were later found. In Scotland I believe the term is "servitude right of access" for things like water and sewerage and these are certainly present in the wording of the title deeds just not in the plans.
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I don't know if this changes things at all but I just tested my static mains pressure and it went right off the scale of a 4 bar gauge and hit the end stop on the way back around. Looks like well in excess of 6 bar. I know static isn't the same as dynamic pressure but it certainly helps to shove the water down the pipe! Given I have this much pressure, what if I was simply to ask him to install a reducing T instead of an equal T so that his branch was 3/4" or whatever the next size down is? I'm just thinking this might be a more productive way to go than potentially ending up in a bun fight.
 
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Can you not speak to the Water Board or equivalent to see what they say / recommend.

It may not even be a legal connection!

If you get something in writing off them with their approval, you may have grounds for retribution in the future.

Once his place is done and sold, you can be guaranteed that he will not come back and rectify any issues.

You really need to do some groundwork with the Local Authorities to see what they require and what their regulations state.

It might help you being on friendly terms with the new neighbours in the future than the current 'short term' neighbour
 
Yes we'll be making sure this is all taken care of but thanks for the warning. The main issues with the title deeds arise from movement of boundaries with consent of the neighbouring landowner but this all needed to be documented properly. There were also some issues with land that had been inherited from parents many years ago but the documents had gone missing. They were later found. In Scotland I believe the term is "servitude right of access" for things like water and sewerage and these are certainly present in the wording of the title deeds just not in the plans.
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I don't know if this changes things at all but I just tested my static mains pressure and it went right off the scale of a 4 bar gauge and hit the end stop on the way back around. Looks like well in excess of 6 bar. I know static isn't the same as dynamic pressure but it certainly helps to shove the water down the pipe! Given I have this much pressure, what if I was simply to ask him to install a reducing T instead of an equal T so that his branch was 3/4" or whatever the next size down is? I'm just thinking this might be a more productive way to go than potentially ending up in a bun fight.
You need to evaluate the volume in litres per min rather than pressure that is what you need. Do it from your worst tap and your best tap. Do it at specific times...1. Sunday Morning 5.00am when no one is up and consuming in the area. 2. Peak time weekday breakfast time before the school run. Also bear in mind if you are in a rural area then utilities switch off area pumps off peak to save money and reduce leakage usually after midnight till 5 ish.
centralheatking
 
Can you not speak to the Water Board or equivalent to see what they say / recommend.

It may not even be a legal connection!

If you get something in writing off them with their approval, you may have grounds for retribution in the future.

Once his place is done and sold, you can be guaranteed that he will not come back and rectify any issues.

You really need to do some groundwork with the Local Authorities to see what they require and what their regulations state.

It might help you being on friendly terms with the new neighbours in the future than the current 'short term' neighbour

I'm trying not to inflame the situation in the first instance, especially until we can establish if we have any actual right to draw water through the neighbour's property. I am also not yet the owner of the home so I'd prefer if the owner handled any "negotiations". I will make some enquiries about the proper procedure to go through when connecting a house to the mains though. I have also emailed my conveyancing solicitor to bring him up to speed on all this.

The 'short term' neighbour might not only be here short term because he has already built two houses on his plot and is about to build a third. I think he intends to remain in the one he's currently living in. He is actually a nice guy and I'm sure we'll get along fine but not if my shower stops working every time someone flushes a toilet in his new build!

So, if we put the legal stuff to one side for a moment, can you guys tell me how best to evaluate the water supply performance. Do I just time how long it takes to fill a known volume and convert to l/min? What would be a decent litres/minute value to aim for in order to feed a 4 bed house with one bathroom (with high volume shower) kitchen, utility room and downstairs shower room? As mentioned above the heating system is GS heat pump with 300 litre unvented water tank which is situated downstairs and has a 3 bar input regulator. My thoughts are to evaluate the supply with the new branch turned off then evaluate it again with the branch flowing the equivalent of having a couple of taps open.

Thanks again for all the advice - really appreciated.:cool:
 
I'm trying not to inflame the situation in the first instance, especially until we can establish if we have any actual right to draw water through the neighbour's property. I am also not yet the owner of the home so I'd prefer if the owner handled any "negotiations". I will make some enquiries about the proper procedure to go through when connecting a house to the mains though. I have also emailed my conveyancing solicitor to bring him up to speed on all this.

The 'short term' neighbour might not only be here short term because he has already built two houses on his plot and is about to build a third. I think he intends to remain in the one he's currently living in. He is actually a nice guy and I'm sure we'll get along fine but not if my shower stops working every time someone flushes a toilet in his new build!

So, if we put the legal stuff to one side for a moment, can you guys tell me how best to evaluate the water supply performance. Do I just time how long it takes to fill a known volume and convert to l/min? What would be a decent litres/minute value to aim for in order to feed a 4 bed house with one bathroom (with high volume shower) kitchen, utility room and downstairs shower room? As mentioned above the heating system is GS heat pump with 300 litre unvented water tank which is situated downstairs and has a 3 bar input regulator. My thoughts are to evaluate the supply with the new branch turned off then evaluate it again with the branch flowing the equivalent of having a couple of taps open.

Thanks again for all the advice - really appreciated.:cool:
yup known volume in a unit time converted to litres per min at the relevant times and report back when all done. We will watch out after next Monday if the schools are back in your area.
centralheatking
put the legal issues back on the vendor as its their
responsibility to answer your enquiries before you exchange or complete or whatever one does North of the border
chking
 
Just did a quick measurement by running 10 litres into a measuring bucket and it took 30s downstairs and 32s upstairs at the largest taps in both cases. So that's 18.75 to 20l/min. Will try it at other times as suggested.
 
Just did a quick measurement by running 10 litres into a measuring bucket and it took 30s downstairs and 32s upstairs at the largest taps in both cases. So that's 18.75 to 20l/min. Will try it at other times as suggested.
I suppose if you get the flow rate verified by an independant
eg chartered surveyer (after you have checked peak rates) then
when or if your property is 'damaged' by the additional demands of this new dev. then you would have recourse without winding up your
neighbour and the vendor could be conjoined into this as part of the
final conveyance documents. To be honest my wife is a barrister and any shared stuff regarding property can and often is a nightmare....access water utilities is an open season for the legal fraternity ...we had one recently it cost the developer £350,000 to
buy out a covenant but he will get his dosh back, it nearly stuffed my latest property deal and we are supposed to be experienced
centralheatking
 
I think the first thing I would be finding out is whether you have a water meter and the position.

Next would be the actual size of the pipe my guess 1" would be 25mm which although you could possibly run 2 houses off it I would want the full 25mm for my house only.

Let's be honest the reason the builder has done this is 1 it's probably saving running a new pipe back to the water main and 2 its saving him the cost of getting the waterboarding out to do the connection.

If it was my pipe I would tell him to do one.
 
Have you considered that your vendor may be selling up to get away from this neighbour?
I don't believe that is the case as they have been neighbours and friends for 12+ years and I know the vendor has other good reasons to move. But I understand why you ask the question.

I think the first thing I would be finding out is whether you have a water meter and the position.

Next would be the actual size of the pipe my guess 1" would be 25mm which although you could possibly run 2 houses off it I would want the full 25mm for my house only.

Let's be honest the reason the builder has done this is 1 it's probably saving running a new pipe back to the water main and 2 its saving him the cost of getting the waterboarding out to do the connection.

If it was my pipe I would tell him to do one.

I don't believe I have a water meter but will need to wait to hear back from Scottish Water on Monday who I have emailed.

The pipe is standard MDPE pipe so is 25mm o/d and 20.4mm i/d

I did some dynamic pressure measurements today which I'd appreciate feedback on. Basically I ran the taps at various flow rates and then measured the pressure while timing the water which flowed in 60 seconds into a measuring bucket. I only have a 4 bar gauge but the needle can pass beyond 4 until it hits the end stop which (assuming it's still linear at that point) would be equivalent to 6 bar.

Flow 0 litres/min - static pressure off the scale of my 4bar gauge so 6+ bar
Flow 5.8 l/m - dynamic pressure still off the scale so 6+ bar
Flow 7.6 l/m - pressure still off the scale so 6+ bar
Flow 12.5 l/m - pressure approx 5 bar
Flow 15 l/m - pressure 3.85 bar
Flow 16.7 l/m - pressure 3.1 bar
Flow 19 l/m - pressure 2.3 bar
Flow 20 l/m - pressure 1.85 bar
Flow 22 l/m - pressure 0.9 bar (kitchen and bath taps both on)
Flow 24 l/m - pressure 0.3 bar (kitchen, bath and utility taps on)

Those last two I had to estimate flow as I couldn't measure them all at once but you can see how the pressure rolls off quickly after 20 l/m

By extrapolating on a chart, I think my static pressure might be as high as 10 bar. Based on that assumption and some distance measurements on google maps I have come up with this prediction about what will happen if both us and the new house supplied from our branch were both to draw 15 l/m at the same time.

Pipe total length 670m. Shared length of pipe before branch 100m. So assuming the pressure drop is equal across the full length, at 15 l/m it is currently dropping 6.15 bar and so 100/670 of that is 0.918 bar dropped in the first 100m with only my house drawing 15l/min.

Pressure drop increases by the square of velocity so if the new branch also took the same water flow, the velocity would double and the pressure drop across the first 100m would quadruple to 3.672 bar. That would in turn cause a reduction in dynamic pressure to me of (3.672 - 0.918) = 2.754 bar at the same 15 l/m flow rate. That means my 3.85 bar would become 1.096.

Anyone know this stuff well enough to check my calculations and assumptions? I tried working with flow calculators but they all hinge around using things like pipe roughness figures which I can't really judge for a 20 year old pipe. So I figured taking actual measurements would be best.

Thanks to all once again.
 
I did some dynamic pressure measurements today which I'd appreciate feedback on.
You've essentially proved that a 25mm is going to be fine for one dwelling but if some clown tries to share it with more houses you're not going to be able to have a decent shower at the same time as your neighbour(s) or have unvented hot water system without installing a whacking great (expensive and large) accumulator.

I suspect that you are falling into the trap of trying to persuade yourself that something that is not okay is going to be okay because you want it to be okay for some unrelated reason.

I wouldn't buy such a property until it had its own pipe that went to it straight from the water company's meter with no funny business. Or, at a pinch, I'd get a professional to specify and quote for an accummulator and knock the cost of the buying price.
 
You've essentially proved that a 25mm is going to be fine for one dwelling but if some clown tries to share it with more houses you're not going to be able to have a decent shower at the same time as your neighbour(s) or have unvented hot water system without installing a whacking great (expensive and large) accumulator.

I suspect that you are falling into the trap of trying to persuade yourself that something that is not okay is going to be okay because you want it to be okay for some unrelated reason.

I wouldn't buy such a property until it had its own pipe that went to it straight from the water company's meter with no funny business.

I see why you might say that but really I'm just trying to make sure I'm not worrying about nothing because this issue could potentially cause our purchase to fall through and I don't want that to happen without having a really good reason. I think I have done enough research to justify formally objecting to the branching of our main so I'll take that up with the vendor and leave it to him to sort out with the neighbour.

I was just curious really whether my pressure/flow measurements indicate a satisfactory supply at the present. I'm already convinced that they would become unsatisfactory if the neighbour takes half the water away.

Thanks.
 
Using a little calc which I have found to be quite helpful and based on the following numbers based on neighbour using same volume of water as you then you can see quite plainly that you will be running out of head when total flow exceeds 40 LPM, ie 20 LPM each, with 40 LPM through the 80 M section and 20 LPM through the 500 M length to your house.
I have done the calc first based on no neighbour teed off the 580 M length. The other calcs are based on 30,40&44 LPM through the 80M length and15,20&22 LPM through the 500M length.

LPM LM DPbar LM DPbar LM DPbar DPbar DPDiff
15 580 2.1 80 1.05 500 1.83 2.88 0.78
20 580 3.6 80 1.79 500 3.11 4.9 1.3
22 580 4.3 80 2.13 500 3.71 5.84 1.54

Can't get numbers lined up above but if one takes the 20 LPM number, the pressure drop is 3.6 bar with no neighbour connected and 4.9 bar with neighbour also using 20 LPM, a difference of 1.3 bar.

 
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If you want to calculate it properly, for MDPE pipe e is around 0.0015mm. Whilst in theory, pressure drop is linear over equivalent length - fittings at the flow end will distort this negatively.
 
Hi Craig,
If I were in your position I would seek advise from Scottish Water.
It is the responsibility of Scottish Water to supply water at a minimum pressure and volume. When you bought your house your either paid for or inherited rights to receive a potable water supply at a minimum pressure and volume from Scottish Water. Your neighbour is about to breach this right. Also it is for Scottish Water to approve any connection to their infrastructure. Any new connection is subject to approval and payment of infastructure charges if appropriate. I suspect Scottish Water will be very interested in this.
I am aware of Water Bylaws in England from when I worked for Anglian Water and Northumbrian Water, but I cannot for certain say its the same as in Scotland. I suspect it is the same and if it had happened in my patches the last thing I would want is another DG2 on the list.

Here are a couple of links to get you started but speak to Scottish Water.

1568559501874.png
 
Using a little calc which I have found to be quite helpful and based on the following numbers based on neighbour using same volume of water as you then you can see quite plainly that you will be running out of head when total flow exceeds 40 LPM, ie 20 LPM each, with 40 LPM through the 80 M section and 20 LPM through the 500 M length to your house.
I have done the calc first based on no neighbour teed off the 580 M length. The other calcs are based on 30,40&44 LPM through the 80M length and15,20&22 LPM through the 500M length.

LPM LM DPbar LM DPbar LM DPbar DPbar DPDiff
15 580 2.1 80 1.05 500 1.83 2.88 0.78
20 580 3.6 80 1.79 500 3.11 4.9 1.3
22 580 4.3 80 2.13 500 3.71 5.84 1.54

Can't get numbers lined up above but if one takes the 20 LPM number, the pressure drop is 3.6 bar with no neighbour connected and 4.9 bar with neighbour also using 20 LPM, a difference of 1.3 bar.


Thanks for taking time to work this out - I get similar figures albeit using the later figures for distances which were 100m from main to branch and another 570m to our house from the branch (670m total). I worked it out at 15 lpm each my dynamic pressure would drop by 2.75 bar compared to if I was drawing 15 lpm with no branch installed.

If you want to calculate it properly, for MDPE pipe e is around 0.0015mm. Whilst in theory, pressure drop is linear over equivalent length - fittings at the flow end will distort this negatively.

Hi - yes I came across the figure of 0.0015mm which I then divided by 20.4mm to get the relative roughness of the MDPE pipe. The thing is, this pipe was installed 20 years ago so who knows what the inside walls look like now and how many joints are installed etc. I think this is why I found it quite difficult to get theoretical calculations to correlate with actual static/dynamic readings taken empirically. You also need to work out the Reynolds number and take account of viscosity due to temperature of the water. I found you can make reasonable assumptions in each case to simplify the equations but could never quite construct a model which worked for me at each empirical flow rate. For all I know there could be leaks or kinks or crushed sections of pipe. This is why I chose in the end to focus on the empirical results with a bit of extrapolation.

Hi Craig,
If I were in your position I would seek advise from Scottish Water.
It is the responsibility of Scottish Water to supply water at a minimum pressure and volume. When you bought your house your either paid for or inherited rights to receive a potable water supply at a minimum pressure and volume from Scottish Water. Your neighbour is about to breach this right. Also it is for Scottish Water to approve any connection to their infrastructure. Any new connection is subject to approval and payment of infastructure charges if appropriate. I suspect Scottish Water will be very interested in this.
I am aware of Water Bylaws in England from when I worked for Anglian Water and Northumbrian Water, but I cannot for certain say its the same as in Scotland. I suspect it is the same and if it had happened in my patches the last thing I would want is another DG2 on the list.

Here are a couple of links to get you started but speak to Scottish Water.

Thanks for that - yes I did email Scottish Water and they eventually got back to me to say that they couldn't really comment on the suitability of the pipe to supply two houses and to consult a professional plumber! So that suggests there are no clear-cut guidelines or rules about pipe size/length for a dwelling. What they did say however is that I (as original pipe owner) would have to consent to my neighbour taking a supply from my pipe and that the new build property owner would have to "consider" (emphasis mine) applying to Scottish Water for a new water connection solely for their property. So even here, they didn't use the word "must" - only "consider".

Anyway, the good news is that our vendor received legal advice in the meantime and then approached the neighbour from a position of knowing he could formally prevent him from using the pipe. But in the interests of good relations, they have agreed that the neighbour will install an upgraded 50mm pipe section between the mains and the branch and this will then be branched to supply each property equally. This is acceptable to me since the 50mm pipe will have a cross sectional area of more than double the 25mm pipe and so my supply should actually improve slightly even when both properties are drawing 20 lpm. It also means that the first 100m of piping are shared and so will have shared responsibility for cost of repair or replacement in future.

So thanks again to everyone who offered advice - very much appreciated!
Craig.
 
Thanks for taking time to work this out - I get similar figures albeit using the later figures for distances which were 100m from main to branch and another 570m to our house from the branch (670m total). I worked it out at 15 lpm each my dynamic pressure would drop by 2.75 bar compared to if I was drawing 15 lpm with no branch installed.



Hi - yes I came across the figure of 0.0015mm which I then divided by 20.4mm to get the relative roughness of the MDPE pipe. The thing is, this pipe was installed 20 years ago so who knows what the inside walls look like now and how many joints are installed etc. I think this is why I found it quite difficult to get theoretical calculations to correlate with actual static/dynamic readings taken empirically. You also need to work out the Reynolds number and take account of viscosity due to temperature of the water. I found you can make reasonable assumptions in each case to simplify the equations but could never quite construct a model which worked for me at each empirical flow rate. For all I know there could be leaks or kinks or crushed sections of pipe. This is why I chose in the end to focus on the empirical results with a bit of extrapolation.



Thanks for that - yes I did email Scottish Water and they eventually got back to me to say that they couldn't really comment on the suitability of the pipe to supply two houses and to consult a professional plumber! So that suggests there are no clear-cut guidelines or rules about pipe size/length for a dwelling. What they did say however is that I (as original pipe owner) would have to consent to my neighbour taking a supply from my pipe and that the new build property owner would have to "consider" (emphasis mine) applying to Scottish Water for a new water connection solely for their property. So even here, they didn't use the word "must" - only "consider".

Anyway, the good news is that our vendor received legal advice in the meantime and then approached the neighbour from a position of knowing he could formally prevent him from using the pipe. But in the interests of good relations, they have agreed that the neighbour will install an upgraded 50mm pipe section between the mains and the branch and this will then be branched to supply each property equally. This is acceptable to me since the 50mm pipe will have a cross sectional area of more than double the 25mm pipe and so my supply should actually improve slightly even when both properties are drawing 20 lpm. It also means that the first 100m of piping are shared and so will have shared responsibility for cost of repair or replacement in future.

So thanks again to everyone who offered advice - very much appreciated!
Craig.
Nice Result - Well done.
 

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