My siphon system is two 6 inch pipes sharing a single vent. The entire system is inside of the dam. I used a 10 inch sock pipe to bring the water level of the pond inside the dam to the vent. Not pictured is the 18 inch piece of culvert pipe I put over this that acts as a pit. I ran a 4 inch piece of pipe to the surface with a grate flush with the ground for the air to enter. I also capped the pit with a concrete cap and covered it with dirt and grass. My dam is 3 feet higher than the water level and I live in an area with an 18 inch frost depth. Even in southern climates, You wouldn't have to worry about debris clogging the vent or having a pipe to mow around with this design.
Edit: I'm adding a drawing that isn't exactly to scale of what I did, but maybe is representative of my design.
I extended the sock over the tee to keep any dirt from entering the sock pipe as I backfilled. I removed it once I had everything backfilled and compacted.
I wish I had taken more pictures. I installed this in October 2010 and I haven't had a problem with it yet.I did a search on siphon systems and didn't come up with any designs for cold climates. I did find some post about not being able to do an automatic siphon system in cold climates. So I just wanted to put something on here in case somebody searched for it.
I just finished another pond with this same design. It is a small 1/3 acre pond. It has a watershed around 3 acres. So two 4 inch pipes should be enough. I just finished it mid September. So here are some pictures of that install with a little description of what I did:
I used two 4 inch sdr 35 pipes for the primary drain with a 2 inch vent. I used a 6 inch sock pipe to allow the water level inside the dam up to the 2 inch vent. All this is just in front of the core.
Here you can see where the sock pipe resurfaces on the slope of the dam.
I covered the sock pipe in #2 gravel.
I'm at full pool and my grass is coming up, I haven't had enough rain to confirm if it will go into syphon. My dam is 16 inches higher than the full water mark and my emergency spillway is 6 inches lower than the dam.
Is there any news on this build with regards to achieving full siphon and if it functioning during the winter freeze? The best I can tell I'm somewhere around a 5' frost line on most maps I have found online when going with the next lower level for safety with water pipes. I really like the advantages of this type of system for removing the lower oxygen water at the bottom of the pond and allowing better oxygenated water to enter the pond.
I haven't had enough precipitation in the last 10 years to make the pipes kick into siphon mode during the winter freeze. I have no reason to think that it wouldn't work during the winter freeze, we just haven't had enough rain to make it go into siphon during winter freeze. I have seen 6 inches of snow weigh down the ice covering my pond push some water out the drainage pipes, just not enough to make it go into siphon mode.
This spring I had a muskrat tunnel down next to my vent and into my siphon pit. I had to dig it out and make sure the tunnels didn't cause any problems with my dam. Luckily it was just in the area of my pit. So while I was doing repair work, I decided to make some modifications. One of the problems with a single vent with 2 drain pipes was that at the start of siphon mode, my pipes would alternate the siphon until the water level raised a little more. It still went into full siphon mode, but probably allowed my water level to raise faster then it would have with two vents. So I modified it so each pipe has its own vent. I would recommend that if you go with dual pipes. I also made my pit with a concrete bottom and concrete blocks all the way to the surface as I never thought a muskrat would get into my system. I'll load some pictures of the finished product here soon.
Yes, pictures and explanation in words would be very helpful. I can't understand how these things work. In the pictures above I also don't understand why there is a green pipe sticking vertically up in the bottom of the empty pond (3rd photo down) But in the next set of pictures it seems to have a different design with no 'stand pipe' but a sock instead?
How does the vertical pipe work?
Where does the air vent draw air from since the vent pipes seem to be sealed?
Here is the siphon pit when I dug it out. You can see the vent on the left side of the picture. The white culvert was cut to allow it to sit over the 6 inch pipes which left an opening under the 6 inch pipe where the muskrat tunneled into my pit.
Here is a picture of the modified pit. I used an irrigation box for the surface cover.
Why do you make such a long sock pipe? I would think that it only needs to be under the water below the frost line plus a couple feet for safety. With the way you have it, your sock pipe could freeze if your pond was low. This would only be a problem when the ice level is below your sock level.Using a solid pipe that is under frost line coming up near the bottom of the pond with a pile of rock on the end may work better if you live in a area that has a lot of droughts. For those of us that work on a very low budget you could use a lot less rock. I like the idea of getting the bad water out first. Any idea how much water would come out a 4 inch pipe?
The sock pipe is used only for the water level to the vent. The only water that exits the pond from the sock pipe would be what is sucked up the vent. This works like any siphon system only the vent is below the ground level. Instead of running a vent back to the pond, I brought the water level inside of the dam. This way it is out of the way of mowing, and frost proof.
nehunter, the length of the sock pipe is not crucial, I just used what I had and covered it with gravel. The sock pipe is not an intake for the siphon system. It only allows the water level to reach my vent.
I have posted pictures of two siphon systems from two different ponds on this thread. In the second picture from my original post, I had two 6 inch pipes connected with a tee as the shared vent. In my last picture posted on 12-3-2019, I have cut out the tee and put two separate 2 inch vents and concreted the bottom and laid block up to a irrigation box that I purchased from Lowes. You can see the water level up to the two separate vents.
I created this thread to show how I modified a standard siphon system so it can be used in northern climates. There is information out there describing how siphon systems work so I didn't go into detail on that part. I noticed some confusion on my design and wasn't sure if it was on siphon systems or how I modified it to work in my design.
Forgive my ignorance but i could really use help in both areas. A link to a diagram or explanation on how the standard cold weather siphon system works would be good for us to get the typical install plan under our belt.
Then tell us how your system works. It looks like in the pictures there are several variations on your system(s) based on how the pipes travel either vertical from the bottom of the pond or lay horizontally in the pond, plus, can't tell what is going on in all of those buried couplings and vents.
My Dam is 3 feet higher than the water level and the frost depth is 18"-24" in my location. So I have the depth needed for my vent to be below the frost line. Most siphon systems have a pipe that extends back to the pond usually above ground for the vent. My modification was to bring the pond water level to the vent all underground. I used a sock pipe and covered it with gravel on the inside slope of the dam and it extends into my pit so the water level in my pit is the same as the pond.
I had a 6" pipe in the bottom for a construction drain that I put a vertical pipe on it with holes drilled in it and covered it with gravel as a filter. On the back side of my dam I have a 6" valve on it so I can drain my pond down when I need to work on it. I also have a smaller pipe with a valve on it that I use to irrigate my garden and berries in the field below my pond. Here is a picture of the valves while I was working on it.