In this Instructable I will show you how to build an irrigation system for a small vegetable garden that is completely powered by the curvature of space-time. At this point, you may be thinking that this is something in the realm of science fiction, but it is quite real and possible. You won’t need fancy equipment either. Everything is readily available at your local hardware, plumbing supply store or on the Internet.
In Einstein’s General Theory of Relativity space and time are not two separate concepts but are seen to be essentially the same thing and can be treated as a single entity called space-time. Einstein realized that massive objects like stars and planets caused a distortion or curvature in space-time. The effect of that distortion is what we call gravity. Imagine setting a large body in the center of a trampoline. The body would press down into the fabric, causing it to dimple. A marble rolled around the edge would spiral inward toward the body, pulled in much the same way that the gravity of a planet pulls at rocks in space.
Stay with me as I explain my system. You may not be able to build a system completely like mine. However, I hope you find one or more ideas here that you can use in your own system. Please leave a comment if you do find something useful here. If you like this Instructable, please vote for it in the Backyard contest.
The heart of the system, quite literally, as it pumps life-giving water just like a heart pumps blood, is a hydraulic ram pump. In this Instructable I will not cover the concepts or the building of the ram pump itself in any detail. There are several Instructables and web sites that already do this better than I could. One of my favorites is this one, LandToHouse.com. The site has some excellent videos, plans for building your own pumps and completed pumps for sale. What I am going to cover is the whole irrigation system that was built around the ram pump.
In order for the ram pump to work there are at least two significant requirements:
· 1. The Ram Pump will need a continuous flow of water to operate. A fast moving stream works, standing water in a pond doesn’t.
· 2. The ram pump requires a vertical drop in the water from the source to the pump. This vertical drop is called head. There is a ratio that determines the results of the pump and that is 1 foot of head will give you 7 feet of lift.
In my terrain I have a small stream that runs downhill behind our vegetable garden. The source of the water is a small pool in that stream. Over a 100 foot distance in the stream, there is a five foot drop from the small pool to the location of the pump. Using the ratio described above, my five feet of head allows my pump to lift the water up to 35 feet, which is more than enough to get it from the stream to our garden.
The sequence of this Instructable is based on the way the water flows from the stream to the garden.
This equipment list is what I used in my system and is highly customized for my terrain, garden size, etc. It is only a suggested list for someone else building a similar system.
· Hydraulic Ram Pump
· Flex Pipe for Drive Pipe
· Screen material and hose clamps
· Rebar and zip ties
· Various garden hoses and hose fittings
· Water storage containers (I used 50-gallon metal barrels)
· Rain Barrel Soaker Hoses and Fittings
Step 1: The Drive Pipe
The pipe that takes water from the water source and brings it to the ram pump is called the drive pipe. Ideally it should be a straight, rigid pipe. However, given the terrain around the creek, I had to go with flex pipe. I used a 100 foot length of plastic 1¼ inch diameter flex pipe.
The intake at the top of the pipe is immersed in a small pool within my creek and held down with some large rocks to keep it under water at all times. I covered the opening with a wire mesh “sock” that I made from some window screen material and picture hanging wire. This lets the water flow in yet keeps things like leaves, sticks, fish and other debris from making its way into the pipe and clogging the ram pump. I secured the wire mesh to the flex pipe using a hose clamp.
The intake opening is the only part of the flex pipe that must be underwater. The rest can be on the ground, in the air, or wherever it needs to be to have the water flow to the pump. The main thing is that it should flow downhill as straight as possible. There should not be any dips in the pipe. Small sideways bends don’t seem to affect the efficiency of the pump too much. The first year I had the system set up we had a very heavy rain and the creek became a raging torrent. My flex pipe and the pump were washed several hundred feet downstream and turned into a jumbled mess. It also caused the flex pipe to kink in several places requiring some major repairs to it. Since then, in addition to the large rocks near the top of the pipe, I have used some rebar and zip ties to secure the pipe so it doesn’t wash downstream in a heavy rain. I would not guarantee this will hold after a steady week of heavy rain, but it holds well most of the time.
The flex pipe is made of a somewhat rigid plastic that once kinked doesn’t go back to its round shape. In order to repair the kinks I had to cut the kinked section out, and then use a pvc coupling and some hose clamps to put the two cut ends together again. Since I had to do this in a few places, my 100 foot flex pipe is probably about 95-97 feet long by now. This does not seem to have affected the efficiency of the pump.
At the bottom end, the flex pipe is connected to the ram pump using a union.
Step 2: The Ram Pump
The garden area has a stream running just downhill from it and we thought it would be great to tap into the stream to get water for irrigation. The question was how to get the water up the hill from the stream to the garden. We thought about getting a gasoline powered pump but that was not an attractive option. The gas pump would have been dirty, noisy and inconvenient as we would have to run the pump every few days for a few hours.
One of our friends told us to look into using a ram pump. Since I didn’t know anything about them I did some research and found that my terrain met all the conditions for such a pump to work. I purchased a complete pump and tried a limited proof of concept on a part of the garden. The system worked beautifully! The next year I expanded the system to cover the entire 20 x 60 foot garden.
According to Wikipedia, the ram pump uses the water hammer effect to develop pressure that allows a portion of the input water that powers the pump to be lifted to a point higher than where the water originally started. The ram pump requires no outside source of power other than the kinetic energy of flowing water, thanks to the curvature of space-time. Ram pumps have been around since the 1700’s. You can read all about their history here: Hydraulic ram.
My ram pump’s input components have a diameter of 1¼ inches so it is considered a 1¼ inch pump. It sits at the side of the creek. I have it secured using a piece of steel pipe and some zip ties. Every spring I set up the whole system and start the pump. It then runs continuously until the fall when we put the garden to bed. The only time the pump stops is if we have a week or so in August when there is not enough rain and the creek slows to a little trickle. During such time we still have enough water to keep the garden watered, thanks to the storage component of the system that will be described shortly.
Step 3: The Splitter
The ram pump pushes the water from the stream uphill to the garden through the delivery pipe, which is just an ordinary garden hose that is connected to the exit of the pump using a union. The end of the pipe pours the water into a 1 gallon plastic bucket suspended about 6 feet in the air on a wooden post. The water eventually goes to eight 50-gallon barrels, numbered #1 - #8. The small bucket splits the water evenly between the two sides of the system, to barrel #4 on the left and barrel #5 on the right. I used to have a simple Y splitter attached to the delivery pipe, which sent water to either side, but I found that it didn’t always send water evenly to both sides. I had to constantly adjust and fiddle with it. This year I tried a different method to split the water. If the small bucket has some water in it, there is a little water pressure pushing downwards. Thanks again, curvature of space-time. This pressure forces water out of the two openings on the bottom. As long as there is enough water in the bucket to cover the two holes, water flows evenly to both sides. I put valves at the bottom on each opening in case I had to adjust the flow to keep a steady water level in the bucket. To my surprise it works just fine with both valves fully open. I am not an engineer or fluid expert and I suspect that there are formulas to figure all this out. I just tried what seemed to be a common sense solution that just happened to work.
Step 4: Water Storage
During my proof of concept, I determined that it was not practical to route the water directly from the pump into the garden beds. This would flood the garden. Anyway, we have about 16 rows to irrigate so the flow has to be spread among them. Adding valves to shut the water off is not a good idea because for the pump to keep working the water has to keep flowing through the system. If I shut of the water at the top, the pump would stop working. I could also have just gone down to the pump to start and stop it as needed, but this also seemed like a big pain. It is a process to get the pump started and I didn’t want to do that every few days. Also, there is a lot of brush with thorns between the creek and the garden that I didn’t want to be going through more than I had to.
What I needed was to have some way to store the water near the garden and then use it as needed for watering the crops. A friend of mine offered me some 50-gallon metal barrels with removable lids that had been used to hold fruit juice concentrate. These barrels were clean, lined with Teflon, and food safe. Best of all I got them for free. It is good to have friends that can get you free stuff.
I drilled three holes into each barrel. There were two holes near the top on opposite sides of each other, one for inflowing water and one for overflow water going out. The third hole was about half way between the two other holes but this one was near the bottom of the barrel. This hole would be the outflow that would go to the garden beds. Each hole was fitted with male garden hose fittings so I could attach female garden hose ends. The hole on the bottom was outfitted with a faucet that took a standard garden hose. On the first few barrels, I drilled the overflow hole a little lower than the inflow hole. On later barrels, I drilled them at the same level. I found that it did not matter either way. By having the two holes at the same level, I could use the barrel on either the left or the right side. The angle of the input and overflow hoses determined the direction of the water flow.
I placed the barrels on cinder block platforms, each barrel slightly lower that the one before it. On the left side, the water flows from the splitter bucket to barrel #4. The overflow from barrel #4 flows into barrel #3. The overflow from barrel #3 flows into barrel #2. The overflow from barrel #2 goes into barrel #1 and that overflow goes back to the creek. The same thing happens between barrels #5, #6, #7 and #8 on the right side. Thanks again, curvature of space-time.
My proof of concept was done with three barrels and I set up the barrels so they flowed down in only one direction from barrel #1 to #3. Then I didn’t need the whole Y splitter situation. When I expanded the system I went from three to eight barrels, numbered #1 - #8 from left to right. The problem with that many barrels was that without the Y splitter, barrel #1 would have to be about twice as high as barrel #5 and so on. I already have to stand on a cinder block to look into barrels #4 and #5 when checking the system. I would have needed a ladder to get to barrels #1, #2, and #3. More importantly, I wasn’t sure how stable a cinder block platform would be at that height. It needs to hold a very heavy barrel with 50 gallons of water in it. The Y splitter design seemed to make the most sense to me.
The barrels are spaced approximately 5-7 feet apart to cover the rows in the garden. I needed hoses to go from the overflow of one barrel to the inflow of the next barrel. The first year I purchased a couple of 6 foot long hoses that were about $25 each, very expensive relative to their size. Who would have thought that the shorter the hose the more expensive it is to buy. When I expanded the system, I realized that this was not going to work for me. There is a discount store in our area that sells, among other things, gardening supplies. For about $35 I bought an inexpensive 50-foot hose and enough hose mending kits to make up to 10 hose segments. For that amount I was able to cut the hose to any size I needed, attach the hose ends and I was done. Since the barrels all had male hose fittings, I needed hoses that had female fittings on both ends. With my custom solution they were easy to make. The hoses between the barrels tend to stretch a little in the summer sun causing dips. I secured them to the fence with some clothesline tied with taut-line hitches. That way I could adjust the tension on the hoses so the dips are taken out.
It takes about two hours for the ram pump to fill two barrels simultaneously. To fill all eight takes about 8 hours.
Step 5: Soaker Hoses
Now that the storage barrels were full of water, it was time to get it distributed to the garden beds. For that, I used soaker hoses. There is a special type of soaker hose called “Rain Barrel Soaker Hose”. It is made for low pressure gravity powered systems. These are available on the Internet at various websites. Just search for Rain Barrel Soaker Hose and you will find them. One very good site I dealt with was www.mrdrip.com. In addition to the soaker hoses, they also sell all kinds of poly tubing and various fittings so that you can customize the layout of your system to your needs. At the faucet of each barrel I put a Mesh Tee Filter as recommended to keep any sediment in the barrels from getting into the soaker hoses and clogging them up. On one of the barrels I placed a Y splitter with valves so that we could fill watering cans, etc.
In the beds, we snaked the hoses back and forth and buried them one or two inches into the soil with just the end caps sticking out so hoses would not dry out in the sun. The hoses are held down with small metal u-shaped stakes. We found that it is much easier to lay the soaker hoses down before you plant anything because you won’t have to go around and possibly disturb seedlings with delicate root systems.
The short video shows how much pressure the 50 gallons of water in each barrel provide in the system to distribute the water through the soaker hoses. Thanks, again curvature of space-time!
When the whole system is fully operational, the pump brings more water into the system than is taken out by the soaker hoses. We know they are working because when we stick our hands into the soil, it is nice and moist near the hoses. Consequently the barrels are always full and there is always some water going back to the creek via the overflow hoses. During a dry spell, the full barrels provide about two or three weeks’ worth of water without being refilled by the pump. It usually rains again before we run out of water.
Step 6: Winter Storage
I put my system up every spring and take it completely apart in the late fall once the harvesting is done. I don’t like to leave it up because water in the hoses and the pump can freeze and damage them. Since all my hoses and other components have screw fittings, the assembly and disassembly is fairly easy. I make sure there is no water in any of the components, hoses, pump and barrels. I roll up all the hoses, including the flex pipe, making sure I don’t kink it. Then I store everything in a storage shed.
I’ve been using the system for five years with great success. Each year I try to improve the system a little by adding a new feature or correcting something that doesn’t work the way I want. When I put it away for the winter, I make a note of any component that may need maintenance or replacing so I can get what I need before laying everything out again in the spring. In that sense I consider it a constant work in progress.
I hope you have enjoyed reading this Instructable and that you got at least one or two ideas you can use in your own situation.
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