Ram pump to fill a pond?

We have a wet creek with a water flow of 150+ GPM but very little elevation change.

This creek is 70’ below the top of the dam of our new pond.

Would this be a ram pump opportunity?

Thanks Shandy

Ram pumps do not need very much drop to operate, although there is a sweet-spot in terms of drive pipe drop to pump output rise. I want to say 1:7 is the ideal, but it has been a while. That would imply that you would like to see 10 feet of drop to pump water 70 feet. You could likely make do with much less, you would just need to make the pump bigger, and recognize that you were maybe not going to pump as much water as a percentage (although you have so much flow that it likely is not going to be a problem to move quite a lot of water).

I built a pump that had about 10-15 feet of drop in 2" pipe, and it delivered several thousand gallons of water a day. I was not pumping more than maybe 20 or 25 feet, but I observed it reach 40PSI once when I kinked the output tubing. Whether it could still deliver meaningful flow at that pressure is unknown to me, but 70 feet of head only needs 30PSI to overcome. There is lots of good info out there on building ram pumps.

Your first step is to figure out how much drop you can manage to get. Then depending on how much water you want to move, you can size things accordingly. Its a fun project; I kind of miss the sound of it running - they are far from silent in operation.

Thanks for the reply.
We’re gonna give it a go.
This sounds like a dumb question but here it comes anyway…..everyone keeps talking about elevation drop to create force to push water up, but won’t shear force of water flowing create the same force?

Thanks Shandy

everyone keeps talking about elevation drop to create force to push water up, but won’t shear force of water flowing create the same force?

Water only flows when there is elevation drop. The available power is a function of drop times flow. A very gentle slope can produce enough power to move water up a hill if there is sufficient flow volume.

You will likely need at least 2 or 3 feet of elevation from the inlet to the outlet of the "drive pipe" for a ram pump to function. On a gently sloped site, you would probably need to build a dam. If the site is very flat, that will likely flood a fairly large area. The drive pipe needs to be a certain length - I forget the ratio now - but I think it was based on the drive pipe diameter.

There is lots of good info on building ram pumps out there, but first you need to evaluate your site. Google earth shows elevation in the bottom corner, and is a good way to figure out the local topography. You can even use the polygon tool to figure out how much land you will flood if you dam up your creek.

From;how-does-a-hydraulic-ram-pump-work
THE LONG ANSWER TO A SHORT QUESTION- ITS ALL TO DO WITH ENERGY
A hydraulic ram is a clever device invented over 200 years ago that can pump water uphill with no other external source of power except for the water flowing into it.

A ram pump lets you get that water to a tank or location at a higher elevation with a  design that requires no electricity or fuel and only two moving parts.
There is little bit of foundational knowledge on the behavior of fluids. And this is something anyone can understand.
There are three types of energy that a fluid can have, and in civil engineering, we usually convert them to their equivalents as the height of a static column. This distance is called the head.
Understanding the energy in a fluid is how we solve a lot of engineering problems, because in most scenarios, the amount of energy stays the same, and the only thing that changes is what form it takes.
The first type is head from gravitational potential. It doesn’t have an equivalent static column because it is a static column.
The head is just the distance from an arbitrary datum. This one is easy to demonstrate with a tank and tube. I can move this tube around wherever I want, but the level in the tube and tank are always going to be the same. They’re both exposed to atmospheric pressure at their surface and they’re not moving so there’s no velocity. It’s just pure gravitational potential.

The second type of energy is pressure head. In this case, the head is the pressure divided by gravity and the density of the fluid.
So, if I close off the top of my tank and add some air pressure, the level in the tube goes up. The new height is the pressure head, the equivalent static column related to the pressure in the tank.
For a given pressure, a denser fluid like mercury will have a lower head compared to a lighter fluid like water because they have different unit weights.
A good example of measuring pressure head is a barometer. We live at the bottom of an ocean of air, and we like to keep track of the air pressure down here.
One of the easiest ways to do that is to measure how high the pressure can push a static column of a fluid, in most cases mercury.

The final type of energy is velocity head, which relates to a fluid’s kinetic energy.  

For example, I can convert a static column of water to one with some velocity, but I’m never going to get the fluid to a higher elevation than where it started… unless with the one exception.
we change the energy state that the water has.
The hydraulic ram pump takes does this beautifully, because a ram pump is essentially just two one-way check valves, one called the waste valve and the other called the delivery valve.
To get it started, you just momentarily open the waste valve to allow water to freely flow, then let the valve drop and the pump will start.
After that it’s working on its’ own to pump the water uphill above the elevation of the source. Pretty amazing.
Let’s walk through the path of the water to understand how it works.
First, as the waste valve opens, water flows into the pump and immediately out of the valve. But, as it picks up speed, the flowing water eventually forces the waste valve to slam shut.
Now the water is trapped  inside  the pump against the waste valve that closed in its face. The kinetic energy [ moving mass of water ]  is converted to air pressure in a closed air chamber.
This pressure can cause water hammer and damage to pipes etc, but in the case of the ram pump though, that spike in pressure has a different effect.
It opens the second check valve and the pressure spike forces water into the delivery line. This process is cyclical, pumping some of the water and wasting the rest each time the valve slams shut.
You can see what’s happening here in real time: the pump is robbing some of the kinetic energy from the flow and imparting it to a smaller volume of water, which then leaps past a non return valve heading towards the elevated tank a small distance at a time.
It’s the redistribution of the energy that does the trick, converting low head [ pressure ]and high [ fast ] flowing into high head and low flow [ volume] .
The air chamber is included in the pump to smooth out those sharp spikes in pressure and provide a more even flow rate out of the delivery pipe, reducing wear and tear on the pump components.

The other option, depending on your layout, might be a trompe.

This video outlines how it works. You can use it to provide compressed air, or as a water pump. It can operate with a small drop between water in put and out put. It has no moving parts, but setting it up is pretty site specific.