Pond Concept: Artifical stream

I would like to hear your thoughts on this concept. Adding a closed loop to a pond to mimic a stream and to create a current in the pond. Ponds are typically stagnate and a current can help distribute nutrients and increase oxygen levels. To do this I propose adding a looping ditch to the pond. To encourage a current to develop I have imagined two designs. (1) Natural design: one half of the loop is cold (deeper channel shaded by trees) the other half is hot (shallower channel on the sunny side). (2) Mechanical Design: Use a motorized pump somewhere in the loop to stimulate flow.

What do you think? Would adding a current to a pond system be worthwhile in terms of pond health and fish production? Do you think the natural design would work to generate a current?

My personal opinion is that I think this would work pretty much like just putting a pump in the pond itself to recirculate the water there.

A stream might cause more water evaporation than anything.

Maybe I'm wrong though.

Take a salad bowl and put it in the sink, and then direct the flow of water up against the side. You will notice the whole mass of water begin to move. You can do this in a pond with a pump. I don't see the need for the channel.

The downsides of the channel are evaporation and increased heat gain in the shallows. I don't see any upsides.

I think you'd need to identify which aspects of a natural stream-fed pond you want to amplify, and which end results you are looking for.

If, for instance, you wanted colder water or a greater thermocline, I would suggest you dig your pond deeper.

If you wish for greater oxygen carrying capacity, I would focus on maintaining cold water temperatures and introducing some kind of water feature that performed the functions of oxygenation and filtration at once. Imagine a jet fountain, or one of those bubbler-based pumps, that eject water out onto a chinampa designed for the purpose, to collect oxygen-eating nitrogen-rich solids from the water and deposit them where they can become soil instead of causing eutrophication.

If you want shallows for smaller fish and aquatic life to thrive without being wiped out by larger fish, create shallows beside the pond, and perhaps plant willows and install reed beds.

If I were to consider an artificial stream, it would need to fulfill several criteria: it would need to serve the purpose of separating out nitrogen-rich eutrophying elements and oxygenating the water without cooling it unduly.

At the crux of it is this: if energy is to be expended to improve the aquatic conditions, what is the most efficient way to do so? Is it a high-capacity solar-powered bubbler at the bottom of a tube at the bottom of the pond, pumping water out onto a floating raised bed, or is it a much more powerful pump expending who knows how much more energy trying to get a current going on flat land?

Granted, if you are pumping water uphill to another pond, that's a different story. But that's not what you're describing.

-CK

While recognizing the merits of the above responses, I say go for it!

Why?

1. Increased oxygenation. Ok, bubble pumps do this, but that long gurgling stream  is going to cause the oxygenation to flow all around that pond.
2. Increased productive edge!!! Imagine the stuff you can grow asking that stream!
3. Because of number 2, natural water filtration from plant roots.
4. Increased diversity of habitat. A stream will harbor biology that couldn't survive in a pond because fish would eat them, because of higher oxygenation levels, WTC.

I see better quality water all the way around.

Chris, thanks for the detailed reply! I suppose this design is only beneficial if one was able to stimulate a flow using the passive natural approach I described. Otherwise like you both stated just using a pump directly would have the same action. If the natural method works I expect it to be a very slow current, maybe so slow that its useless : (

An additional benefit to the loop is it would create an isolated area to contain plants that propagate via root suckers such as timber bamboo.

Heat rises, but water won't go uphill. You just end up with the warmest water on top. I don't see how you expect to induce a current with one warm shallow section of the stream, on what is presumably flat land.. What you will do is warm the water past the point where it will carry useful amounts of oxygen.

I would go another route. I would have many chinampas with many small solar pumps. I would plant those chinampas with garden crops, with different varieties of rice growing on the margins, and off the shore. I might also arrange some of them to form exclusionary weir habitats as nurseries; undoubtedly, small creatures would find shelter in, around, and under the chinampas as well.

A lot of this depends on where you are in the world, and on what you intend to do with the pond and land.

But let us know how it goes, and good luck.

-CK

I would do it for the beauty!

Using a mechanical pump to elevate some water, and allow it to flow downhill back into the pond. And of course lots of water loving plants, and waterfalls along the whole streambed. And plenty of beautiful rocks.

If you intend to breed fish, many species need running water to perform the cycle, so a steam system with a mix of gravel races, eddies, small still pools and large rocky areas provide all the things fish need, including a degree of aeration - besides habitat for aquatic flora and fauna. It could have both beauty, form and function.

A mechanical pump would provide a continuous flow rate.

I have thought about a building a meandering canal rather than a pond.
I would build it as flat and level as possible,  and use a low power pump to push water from one end to another.
This would mean lots of edge and moving water.

For your design I would block one end of the stream,  then use a solar  pump to move water over the blockage, from the pond to stream.
Displacement should move water all the way around the stream, back into the pond.

Would a water windmill be practical, no power, but needs wind and the cost would be more than an electric pump.
Flow would be slow.
Otherwise a solar powered pump.
You may need to look at the energy required to get the water moving

I’m thinking that if you combine solar heating patterns (less shade on part of it and running next to big rocks with good sun exposure) with some kind of construction, perhaps well-placed fencing or shrubs that direct the primary wind along the path you want the water to take, and with Tesla valves (picture of concept included) built in as water channels, this idea can certainly work. It won’t be very fast-running, but it will probably be enough to serve your purposes, and as previously mentioned, it will give you tons of productive edge.

I forgot to point this out, but the tesla valve setup will make any added energy propel the water in only one direction, so if you make warmer and cooler zones with shade management, it will pay off really well.

Here is a picture of another valve that follows natural patterns better, so it’s probably more stable as an earthwork. The basic idea is that half of the fluid flowing in one direction gets diverted back on itself into the direction it’s supposed to go. This can actually create a coherent current where before there were just some random eddies. I suggest that you put rocks in the ends of the curves right where the water would hit the side to stop erosion, and willows or cattails on the little islands formed by the curves to stabilize them. Minimizing maintenance will be the hardest part of the system.

Sorry, forgot the picture. Here you go:

Myron Platte wrote:Sorry, forgot the picture. Here you go:

Fascinating!

Thanks for sharing.

There are problems with channels though. Not such problems that you might not overcome, but problems that can be easily evaded by doing something else.

For example, sealing the pond. That is probably the very first thing to consider if you are going to build a pond. Every pond leaks at one point of its lifetime. If you build a pond with a circular or elliptical surface area, you will get the least water-soil interface. Rectangular shapes have corners, which might create problems while building it or in the future. A channel has the largest water-soil interface area. You might even double or triple the interface area to the total volume ratio. It significantly increases the possibility of leakage.

At a certain time in the future, you will need to clean the pond. Channels in a pond system have the largest edge compared to their volume, so more debris falls into them and thus they are usually the first to get clogged or mostly clogged. That might be a good thing if you are considering to build a chinampa. You want debris as fertilizer in that case. In other cases, you need to design a pond to stay cleaner. It is harder to clean channels.

Unless you are going to build your channels deep (like 2 meters), temperature difference won't be strong enough to move water. And you need two reservoirs with different shapes. It is certainly true that one length of the channel might be warmer than the other, but water does not know that. It will always do what requires the least energy. Warm water will not be at the top of the water column, warmER water will be at the top. You need a greater temperature difference (actually density difference) to turn the vertical movement into lateral. So you will have two layers, warmer at the top and colder at the bottom. The flow need not halt also, so so you will need a deeper, shaded pond and another shallow pond (a bowl shape) with larger surface area and a channel connecting them. As the shallow pond gets warmer, water at its bottom (its cold water reservoir) will heat up and rise. Meanwhile, deep pond won't be able to heat up as quickly. So you have a cold surface connected with a warm surface by a channel. Warm water from the shallow pond will flow into the deep pond as colder surface water of the deeper pond will sink and later on flow into shallow ponds cold water reservoir to compensate for the volume change. The channel will have two layers of water going in opposite directions. The warmer water layer will get deeper as sun rises in the sky. At a certain point, it will choke up the whole channel and cut the flow. As night time comes, shallow pond with greater surface area will lose more heat due to evaporation. So the movement will get reversed somewhat. The problem is this movement will not make sense if it is slower than certain velocity. If it is too slow, dust will settle at the bottom of the channel, slowly clogging it. It wont be adding oxgen into the system also.

If you really want to create a stream effect, you pump the water to a greater hight and let it flow downstream to the pond. It will oxygenate the water, fish and frogs will love it. Requires minimum excavation work and such. It is also trouble free. If it leaks, just cut it off. The pond will continue to hold water. You can pump water with a bubbler. 1 ft-30 cm rise of water is more than enough for most cases. Search for davidpaganbutler in youtube, for how bubblers rise water.  

Hope it helps

Thanks Myron for the awesome concept of Tesla valves. Also Thank you ayalp for your detailed and constructive criticisms of such a design.

I realize that such a system may not be the most the most practical in implementation, but the design is so cool and interesting. This would be an awesome "fun project" to implement even if it doesn't perform well in the end.

My new design features two ponds a deep cool pond and a shallow warm one. They are connected with equally sized tesla valve channels to promote a unidirectional flow. Attached is another crude diagram.

Keller McKowen wrote:Thanks Myron for the awesome concept of Tesla valves. Also Thank you ayalp for your detailed and constructive criticisms of such a design.

I realize that such a system may not be the most the most practical in implementation, but the design is so cool and interesting. This would be an awesome "fun project" to implement even if it doesn't perform well in the end.

My new design features two ponds a deep cool pond and a shallow warm one. They are connected with equally sized tesla valve channels to promote a unidirectional flow. Attached is another crude diagram.

    Glad I could be helpful! I hope it works out! If it does, let us know, and I’ll see if I can try it.

I have been thinking about doing this as well!
Question:
Would the Tesla valve have to be straight?  I have only seen them functioning in a straight line, not on a curve.

Wendy O'Neill wrote:I have been thinking about doing this as well!
Question:
Would the Tesla valve have to be straight?  I have only seen them functioning in a straight line, not on a curve.

    I think that as long as it diverts half the water back on itself several times, it will work. It might look a little different if it’s curved, but the concept is the same.

I made what I think is a finalized design which I call the Lotus Pond. I made a new thread discribing it's features. Thought I'd post it here as a conclusion to this thread.