Hi!
I am planning on designing and installing an irrigation system for my garden. I have quite a large roof (Bungalow), so can collect rainwater as the primary source of water. I am after a suitable pump to pump this water to the various sprinklers etc. Is there a pump that would provide the same kind of pressure as mains water? I am planning on a system that will deplete the rainwater stores, then switch over to mains water if necessary!
Thanks for any suggestions!
Sparks...
sprinklers etc.
To switch over to mains water if the store is exhausted, and to provide the necessary air gap, you could use a ball float like on a cold water storage tank, with a long connecting rod. You would adjust this so that the valve only opens when the tank is (almost) empty, allowing the mains water into the tank. It would then get pumped out immediately and onto the garden.
The main thing to bear in mind is how much watering you intend to do, and how often. If you plan to store enough water in the first place (and can house it OK) you might not need the complication of adding mains backup.
Neil
This is the kind of thing I was planning (Water level sensor & electric valves all connected to a microcontroller that controls everything)
Do I have to have an air gap in the sprinkler system, or will a non return valve be adequate?
The thing I need is a pump capable of the same flow and pressure as mains water (or there abouts)
I just did an experiment with my pond pump (Draper SWP250A) and although it will empty a 100 litre water butt in about 20 seconds!, when I reduce it down to normal hosepipe size, when connected to a sprinkler, it is a little feeble (Not totally useless, bit a lot less pressure than mains (This was with a 5m length of hose)
I need mains pressure, because I want to use some pop up sprinklers, and also have various points around the garden where a normal hose can be connected, still using the rain water if it is available!
The idea I have, is to bury a main feed pipe all around the garden, then T off this, with electric valves for the different beds/sprinklers/etc.
Then this main feeder pipe will be fed from either the mains water (with the addition of a non return valve and an electric valve) or the rainwater storage using an electric valve and a pump.
I may at some point want to add grey water storage(Bath/shower waste etc), and add this to the system - I am not sure if this will be bad for the garden though.
Sparks...
electric
I was looking at Access Irrigation's design document last week and it said that an air gap was mandatory. I doubt it really is, though, since a double check valve is OK on an outside tap. Best people to ask would be your water supply co.
Perhaps a single-ended shower pump would do the trick? I imagine you would need to install it somewhere frost-free.
although it
These are in your lawn, I suppose. Does the manufacturer specify a minimum pressure needed to get them to pop up?
and
You will need to ensure you can completely drain any pipes which are not frost-protected, either by burial or lagging. Unless you live in Torquay.
If you can use a double-check valve you might be able to use a 3-port diverter valve to select between store and mains.
I have been considering a grey water system - AFAIK it's not necessarily bad for the garden per se, but a lot of shampoos etc are apparently quite alkaline so any calcifuges won't like it much. On the other hand, how much shower gel does one use in relation to the amount of shower water?
Neil
Sounds like a sensible idea to me!
Just been looking on eBay, and there is a company selling well pumps, they do 120l per minute at 4.2bar (apparently double a normal mains water supply) eBay # 4304665518)
Yes, they are for the lawn, I haven't bought them yet though!
Ok, hadn't thought of this... What sort of depth would be insulated enough (in Kent!)
Good Idea! - thanks!
I was thinking exactly the same this morning in the shower!
Thanks for your input on this!
Sparks...
You will need a fairly large storage tank. Oddly enough, the time you need the water most is when you are least likely to have any falling out of the sky :-)
It may help you to know that, E and SE England averages 500-650mm rainfall per annum, the West Country, Wales, Cumbria and the West half of Scotland is around 1m-2m per annum, with the Scottish West Coast being wetter than that and anywhere not mentioned, being between 650mm and 1m.
They are common in France, where well water is often used for watering the garden. The usual system is to have a pressurised reservoir tank, rather larger than the typical domestic hot water cylinder, and to keep that topped up with the pump.
I would have thought that fairly easy to arrange. A float switch that will operate a solenoid valve should do the job. Obviously, mains feed to garden watering equipment has to have a double check valve in it.
Colin Bignell
My next question is, where is the cheapest place to get water tanks! I cant be arsed to bury them, nor do I need to, as there is a "waster" space one side of the house what will be perfect for tanks
I was thinking of using several water butts, interconnected at the bottoms, this has the benefit of being easily expandable with the addition of more butts!
Is there anywhere cheaper than £34.95 for a 220 litre butt?
I don't fancy having to clean a filter every five minutes either!
Thanks for that!
Thanks for the suggestion, but I will need the water from my gutters, so pressurised probably won't be suitable! (Plus the tanks will be more expensive!)
This is what I was planning, although some people have suggested an air gap may be required?
Sparks...
The system suggested in my 1970s self-sufficiency book is to build it of reinforced concrete and line it with butyl rubber. However, I would probably paint the inside with garden pond water-proofing paint. The book also suggests it should hold about 1/4 of the annual rainfall to be useful in the UK.
...
I have a cartridge filter for my well in France, which only needs to be changed about once a year. However, the self-sufficiency book suggests running the water first through a coarse mesh screen, into a settlement tank. The settlement tank then overflows into a sand filter (0.5m of 0.3mm filter sand over 75mm coarse sand, over 75mm fine gravel, over 100m coarse gravel) and thence into storage. However, that is for drinking water and you might get away with just the screen and a settlement tank. Most of the systems seem to include a small tank that will hold enough water to take the initial run-off from the roof, before overflowing into the settlement tank. That should catch the worst of the rubbish, but it will also need to be emptied (a tap leading to a soaker hose perhaps) between periods of rainfall to be effective.
....
I can't see it myself, but it would be easy enough to arrange. Feed the pump from a cistern with two float valves; one fed by gravity from your storage and the second fed with mains water. The second should obviously be set so that the float will not start to drop until water level is low enough for you to be sure that the stored water has run out, but with its outlet still above the highest water level. That would probably be more reliable than a solenoid valve anyway.
Colin Bignell
a 1m plastic cube in a galvanised frame on a pallet base. i.e.
They often go for ~£20, but do vary depending on cleanliness and previous contents. Farmers get liquid feeds and fertilizers in them, and they are often found at agricultural auctions.
Tomorrow, (Wed 2nd) there will be about 20 of these sold at York Auction Centre
Just done a quick diagram of what I am planning for the storage of the water..
Not, it is NOT to scale!!
Any suggestions how it could be better?
I may add more tanks later, but this will be easily done afterwards!
you need a multi stage booster pump- check out machine mart. I have this one which I use for various temporary pumping dutys from just pumping from A to B, and also pressuring mobile toilets from a bulk tank at shows and stuff.
Tim..
I plan to run a feeder pipe around the garden (Buried) in a loop, like a ring main so the pressure loss is kept to a minimum, can anyone tell me the best place to get 1" pipe suitable for this?
Maybe the blue mains water pipe (HDPE??)
Any idea how deep this needs to be buried as to stop freezing damage? (or if it needs to be buired at all?)
Sparks...
You may find that you need to have multiple pipes and a controller, with solenoid valves, to run the sprinklers at different times. The pumped system in my garden can only effectively run two pop-up sprinklers at a time.
That is what the pop-up sprinklers you can buy in French garden centres are designed to work with. They screw into a T-piece with push-on connectors to fit the pipe. I keep meaning to bring some back for my garden in the UK.
In Kent, probably about the depth that allows you to screw the sprinklers into a T-piece and still be flush with the ground when down.
Colin Bignell
A quarter of the annual rainfall over what area?
Yep, The idea I had was a complete loop of 1" pipe from the pump, to the pump, then at every T off this main feeder pipe, a solonoid valve, my controller would then do the rest!
I think I mad an error here, MDPE is what I meant - Screwfix do it for about £15 per 50m (deliverd) anywhere cheaper? (I will probably need 150 meters at a guess)
What pop up sprinklers did you go for out of interest?
Sparks...
The area you are collecting from, which is usually set by the size of your roof.
Colin Bignell
I have no idea of the make. I just got them off the shelf at the garden centre in France.
Colin Bignell
I don't see how you can generalise this. If your bungalow has a roof area of 100 sq m and you want to store water for your hanging baskets you're not going to need anywhere near 1/4 of the annual rainfall stored.
If your house has a roof area of 50 sq m and you want to water your 1000 sq m croquet lawn every evening, you might need a lot more than 1/4 stored to get you through the summer.
Neil
You may find that BES are a little cheaper, they are also good for the fittings and have a bigger range than Screwfix.
That's a pretty indefinite amount then isn't it depending very much on the size of your house and on the area of the roof that actually drains into gutters and 'collectible from' downpipes.
Some of the houses around our village are small and have several acres of land/garden, at the opposite extreme there are big houses on local estates where where the house covers a significant proportion of the total area of the plot.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.