General

Hydraulic Ram Pumps

The recent water crisis in Flint, Michigan, showed how vulnerable and unstable our industrial water system really is. Once it was determined that the public water in Flint, Michigan was indeed contaminated with lead and other dangerous substances, thousands of people were literally relegated to standing in lines to wait for bottled water from the government or other aid agencies. People had no idea how to get clean, potable water for themselves.

Living outside of urban areas obviously brings with it a greater access to more sources of fresh water. Springs, rivers, and lakes are more likely to be found in the woods of Wisconsin than in the barrios of Brooklyn. However, the energy cost of getting that water into your homes, and the greenhouse gas emissions that are usually associated with the energetic cost of moving water, usually come with an ecological cost.

Water and Gravity

If you live in a rural area, or a place where a source of water is readily available, the first thing you should be thinking about is how to get water to the top of your site so that you can use gravity to feed your home and the rest of your land or farm. If you have ever tried to carry buckets of water uphill, you can testify to the fact that gravity is by far the best way to move water without depending on any sort of external energy source.

When using permaculture design principles to design your landscape, one of the most important things to consider is related to how you can use gravity to feed water to different parts of your land. Where you site your home, where you plan to build a small pond, where your main field crops will be placed: all of these considerations are intricately tied to the availability of water and how it can move from one place on the farm to the next.

Unfortunately, not every site is blessed with a plentiful source of water running through the highest part of the land that can be stored and subsequently moved to other parts of the land. More frequently, water tends to find its way to the lower parts of the land as streams and creeks carve out ravines and rifts that tend to be lower than our ideal house site. While many people settle for using pumps to move that water to higher parts of the land where can more easily be distributed and used, the hydraulic ram pump might offer a more “permacultural” solution to getting water to where you need it without relying on fossil fuel energy.

What is the Hydraulic Ram Pump?

The hydraulic ram pump is a way to move water uphill without relying on electricity, gasoline, or any other sort of polluting energy. The hydraulic ram is an automatic pumping device that uses the energy contained in the flow of water running through it to lift a small volume of water to a higher elevation. In order to get the “lift”, you´ll need to have a reliable source of water that drops at least 3 to 5 feet in height as it crosses your land.

The ram pump works by creating a pressure surge that develops when moving water is suddenly stopped through the use of capped PVC pipes and check valves. Water is heavy and is it rushes downhill through a piping system, it is suddenly stopped by a capped PVC vertical tube. The check valve slams shut, essentially pushing the up a smaller pipe that comes off of the main pipe. This smaller pipe is what carries the water uphill against gravity with nothing more than the energy created by the flowing water.

While there are several differing opinions regarding how far and how high you will be able to pump water with the hydraulic ram pump, a conservative estimate is that there is a 1 to 7 ratio. For every 1 foot of drop (or head) that you have, you will be able to raise water around seven feet. For example, let´s say that you build a small reservoir or small dammed pond at the highest point of where a stream enters your land. The drive pipe of your ram pump exits this small reservoir and drops around 10 feet from one part of your land to another. This ten-foot drop would allow you to pump water close to 70 feet in height towards a higher area of your land.

The Possibilities for Ram Pumps

While hydraulic ram pumps may not work for every situation, if you do have a reliable source of water that you need to move from a low point to a high point, there is no better technology that doesn´t depend on any sort of fossil fuel energy. While hydraulic ram pumps may seem to achieve the impossible by working as the mythical perpetual motion machine, they are incredibly useful tools to use the energy of nature to move water to where it can be most useful for your overall permaculture design.

Image via: https://www.permaculturenews.org/2014/04/02/ram-pumps/

Tobias Roberts

After working in the development industry for over a decade, Tobias decided it was time to stop advising Central American farmers how to do things if he didn´t have a piece of land to live coherently with what he taught. Together with his family he runs a small agro-forestry farm, tourism cooperative, and natural building collective in the mountains of El Salvador.

12 Comments

  1. To answer your question about what percentage of the water goes to the new height, and what percentage is waste, it depends on several factors. What follows is a simplification of the actual case. You need a pump that is designed for the ratio of the head of the source water to the head of the pumped water. As an example, if you have 10 feet of head in the source water and you want to pump the water to a 50 foot height, to get the maximum efficiency you will need to have a different pump design than if you are pumping the water to a 20 foot height.

    Having said that, if you have a pump that is designed for the height ratio, if the head of the source is 10 feet and the height of the target is 50 feet, then on a pure conservation of energy basis, you know that for 100 gallons of source water, 20 gallons is the most you could pump to the target height. Because of frictional losses, and other losses you would probably get about 4 or 5 gallons to the target height for every 100 gallons of source water. The important thing to keep in mind is that it does this 24 hours a day, so if you had 5 gallons per minute of source water, it would take 4 minutes to pump one gallon, or 15 gallons per hour, or 360 gallons every 24 hours.

  2. Good afternoon!
    If I want to lift water from a lake, which is, for instance at “0ft”( this is a seepage lake, I do not have a possibility to lift the water at the exit), and I have a spring at 16 feet (2gallon/s), how can I lift 2gallon/s(or more) water from the lake to 6 feet with the springs help without electricity?
    Is it possible?
    Do you meet with this case?
    Sorry for the mistakes and thank you in advance for your answers.

    1. You cannot bring water up from the lake but if you can find a groundwater level high enough to build a small cistern and use it as the source water for your ramp pump.

  3. Good Evening,
    We would like to take water from a stock pond to a ridge with approximately 300 feet of elevation gain. There is currently a high volume/low pressure solar pump installed in the pond. I am curious whether the solar pump could be used directly feeding into the ram pump…otherwise pump up to a tank and then drop it back down to the ram pump. Is there any reason why it wouldn’t work to feed directly into the ram?
    Any other considerations that I should make in the design of the pump for this purpose?
    Thanks!

  4. Hello All,
    I have a question for an issue we have in Kenya. where we try to help local people with providing clean drinking water from a well.
    Because of the remote area an prices of gasoline, we are trying to install a solar powered well pump, to provide enough gallons of water for the local village to have clean drinking water AND not to walk daily 12 mile for just having water. The well is drilled, we have a large source of water, However the depth of the well is 230 feet deep. With just a solar powered pump it is impossible to have the “lift” of water taken care efficiently by the solar pump.

    We are trying to find a solution what works so all people in village have water.

    now I had the idea to use the solar pump for the first 30 feet, and still have enough pressure to attach a hydrolyc ram pump after that to push the last part of the well pipe to get the water above ground.

    Question: Is anyone aware of the possibility to have a solar pump, pumping the water to a RAM pump to use the pressure of the pump in combination with the RAM to successfully bring water up to certain heights?

    Also, is there a formula to calculate pressure intake to level of RAM water lifting?

    Hopefully someone can help or share experience..

    Thnx Marty

    1. I would be inclined to use and old fashioned hand pump type – but with a motorised drive. Your supply pipe should have non-return flap valves at intervals, so that water cannot return down the pipe.

      I have not tried this but I suspect it will work. The non-return valves are a good idea, regardless, I feel.

  5. Hi There, Im looking for some help with calculations for my ram pump.

    I have a ram pump with a 1” drive line going 100 feet to my ram pump
    it drops about 16 feet in elevation from the source over the 100 feet.

    The return is a 1/2” line going about 500 feet on a steep incline of aprox 175’ elevation
    Im getting a dribble about 25 feet from the cabin and about 12 feet below tank

    Can you recommend what I need to do to get the water to the holding tank?
    I’m guessing add an extra 3’ drop to the pump, but would need to add 20 feet of 1” feeder line
    or could I drop to a 1/4” line half way to the end holding tank? or go 1/4” delivery line the entire way?

    I look forward to hearing back from you

    1. Use three 1/2″ Waste walve in for 1″ Drive pipe, it will waste water littel big more but you will get water at desired hight.

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