Piping river water.

[MyrtlevilleHouse]

Hello,
I stumbled on this site today, love it and hope its as useful as it looks!
Im trying to pipe water from an overground stream for watering allotments,
I can take the water upstream and pipe it about 100m to get enough of a fall, through a high wall
and go from there.
My questions are:
what size piping should I use?
should I dig a little pond or catchment where I start my pipe?
what kind of filter should I use?
should I get a water tank and store the water or will I be ok to
just pipe direct from the stream?
and does anyone have any neat ideas for upping the pressure if I need it?

I really hop someones got a few answers or ideas for me! I cant find any ready solutions online.

Thanks in advance:)
M.

[Maykal]

Hi and welcome to the forum,

I don't know much about plumbing and I've never tried taking water from a river, and I'm sure someone will come along with better information, but my thoughts are as follows:

The pressure will be defined by the height of the inlet. The higher the inlet compared to the outlet, the greater the pressure, as the only force in the equation here is gravity. To up the water pressure, you'd have to install some kind of inline pump I would think. What sort of fall are we talking about? From that, you could calculate the maximum obtainable pressure.

You could install some kind of tank, like a water butt, at the allotment end to make sure that you have a good supply of water even when the river runs drier in the summer, or simply to make it easier to fill up a watering can. The hose outlet could have a valve in it to stop the water flowing when the butt is full.

When the water arrives at the allotment end, assuming you have decent pressure from the fall, you could downsize the pipe to get a higher water flow rate which might allow you to get some kind of jet going to aid watering.

At the inlet end, you probably just need some kind of gauze box to stop anything too big getting into the pipe and blocking it. Whatever you do you'll probably need to clear it out reasonably regularly to stop it getting clogged. If the area is prone to freezing, you should also make sure you empty the pipe in the winter (doubt you'll need too much water for the allotment then anyway!) otherwise you could end up cracking it, unless you intend to bury it deep.

I don't really know about the pipe size, probably about an inch?

Hope someone with some experience comes along soon with some better answers.

Cheers,
Mike

[GeorgeSalt]

First question.. where are you? In the UK you'll almost certainly need an abstraction license if you're actively taking water from a river in this way.

If you're running a leat (which is essentially what you're doing), it's usual to install a weir on the river to maintain the flow by regulating the height of the river. If you research micro or pico hydropower projects via Google you'll probably find what you need, if you search irrigation you probably won't! I'm on the wrong PC at the moment, later in the week I can dig out a link to small scale hydropower projects fron the other computer that may be of use.

[boboff]

Hi

Strawbridge takes water from a Stream, I think you need some kind of "sump" with a mid feed for your pipe, filtered, with a tap on the end of it. When not in use the Box fills up and floaty stuff floats away and any silt falls to the bottom of the box. Think Dam with a pipe half way up.

I would use 22mm or I think 25mm blue water pipe, which ever you can get your hands on, and then run this to the taps, where you can either use blue taps or convert to 15mm taps so you can attach hoses etc.

Have fun!

[MyrtlevilleHouse]

Thanks for all that guys, appreciate it!
The fall isnt much more than a metre, its a gently sloping little stream but it never drys up.
Im in the far south of Ireland George, I cant see any trouble arising to be honest, the stream goes underground just below us.
I got lucky this week and found a fibreglass tub (old life raft cover) washed up nearby. Its 1.6m long, 0.8m wide and 0.4m deep. My idea is to find somewhere upstream with a small drop and dig it into place there, leaving the downstream end free. there I could have the mid feed. Above the feed I can cut a gap for the water to leave the tub(instead of letting it flow over the sides all round).
Im still a bit concerned about pressure as theres a bend to negotiate on the way and a slight incline after that. If the incline is too great I can take another route.
Anyone see any pitfalls there? Im just working this out in my head with my fingers crossed.
Thanks,
Mark.

[GeorgeSalt]

I wouldn't dig a sump in at the upstream end, the depth of water at that point doesn't matter but the height of it does. Put a small stone/turf dam in the stream and feed your pipe from that. The pipe should be as high as possible in the dam, but the lowest escape for the water from it. Any excess can flow over the weir you create (so top the dam with large flat stones).

A meter isn't a lot of fall, so you're not going to get much in the way of pressure. Use the largest diameter pipe you can to reduce resistance - 25mm blue water pipe would be fairly standard and easy to get hold of. Better then to just pipe the water to somewhere convenient to use it. Dig and line a cistern on your plot and allow the water to keep it full. Allow the cistern to overflow back to the stream. Don't bother filtering for garden use.

Unless you can dam and pipe from higher up the hillside there's nothing you can do about the pressure.

[Davie Crockett]

Have a look at making a Barsha pump (http://www.youtube.com/watch?v=mN9iLNHGOYI) which doesn't need much of a rise to be effective. It may save you having to go too far upstream.

[Odsox]

..... or you could use a hydraulic ram pump in the stream to pump your water to a header tank, that would give you a reasonable pressure.
Google Hydro Ram, useful little gadget that doesn't need external power and can even be place BELOW your stream level.

[MyrtlevilleHouse]

Thanks for the help everyone, I got it done this evening. Serious sense of achievement I must say, Ive been listening to that stream with so much intent these last few years its nice to finally do it. The dam idea came in very handy in the end and I think the fall is probably more like 2m. Theres no shortage of pressure really. I think I might just connect it straight to the taps from there and see how that goes.
Thanks again!