Pond Boss Forums POND CONSTRUCTION Building a dam PVC Siphon System by Pond Dam Piping - Pro's and Cons?

Can anyone elaborate on the siphon system by Pond Dam Piping? Has anyone seen this system built and operate after the lake fills up? Does the pvc pipe hold up well? Does the emergency overflow valve system work okay? I'm building a 3/4 to 1 acre pond that will have an elevation change of around 10 to 12 feet - from the inside(water side) of the dam to the shallow end. What about the pipe freezing, since it goes over the top of the dam?

I have a 12" PVC siphon pipe on one of my ponds
which is on a creek with a large watershed. I
haven't seen it work yet because the pond has not filled. The pipe was acquired at a local water co. at their cost. I know nothing about the company you refer to, but I'd guess that they work quit well. (just ask them if you don't beleive it). These systems are fairly common around my area in NE Texas. The pipe actually
goes through the dam (not over it) at the water level, and angles downward to a level where the
outlet is lower than the inlet. Emergency overflows are about a foot higher than the draw
level of the pipe. Ice could only affect the pipe at the water level down, and a freeze would have to be quite severe to create a problem.

A biologist suggested having a bubbler system under the pipe to prevent ice up / freezing in the winter for this area. Never tried it myself, but makes sense.

Thanks for your reply Squeeky. I called and got a quote on the pond dam piping siphon system. The 8" system runs $296.80 for the fitting package(four elbows with collars and a valve) and 209.30 for the screen. I supply the 80 to 100 feet of PVC pipe. This seems pricey...... The draw that I'm planning on placing the pond isn't a huge watershead, yet it is ample. The pond will be in East Texas(Lufkin) area. May I ask what your cost was for your setup? How big will your pond be a full capacity? What kind of emergency overflow setup do you have? Did you help the contractor set the pipe up and into the dam? The 12" setup I think runs around $1200 bucks, not including the straight pipe. Will your pond be used for recreation(fishing) or mainly for livestock? What is the name of the local water company you purchased your setup?

The dozer contractor purchased the pipe from
(I think)the Lamar County Water Co. The pond will
primarily be a water source for livestock. I did add about 500 bluegill and will probably move some catfish and bass to the pond next spring.
The total cost was about $1000 for 240' of pipe
plus elbow fittings (did not use a butterfly
or knief valve, but wish I had. However, a 12"
butterfly valve will run over $500 alone).

In response to the question about the siphon system ,I saw my siphon handle the latest hurricane here in mid west Ga. quite nicely.
I have a 2 acre pond fed by a live stream with ,a 10" pvc siphon,on Monday (Sept 27) w/3.8"s of rain,the pond being at full pool filled over the pipe but the siphon action started and with in about 3 hours had pulled the level back down almost to normal pool.In 2 years I don't think my spillway has ever seen pond water and it seems to me that this is exactly what you are looking for in a water management system.
Don't be too concerned with your inital cost when sizing your pipe as the peace of mind is priceless.

I installed one of our siphon systems in a 2.5 acre pond with 6" pipe with about 30 acres of watershed and it had no problems handling the two hurricanes. It was amazing to see it running full force the first time. It's been installed for about five years now and had no problems with it. I got the parts from my local hardware store. There's nothing fancy about this one, no valves, just a vent for maintenance free automatic operation. It just make quite a bit of noise just as it begins to break the suction.

In response to marks post about the cost of the siphon system, that does seem a lil pricey for the fittings for the 8" siphon. The siphon system has been around for many years, but a company I buy my systems from has perfected it using elbows that are made for different slopes and using a screen on the vent pipe, to keep turtles, trash, etc. from blocking the vent pipe. They dont have a website yet, but their number is 1-877-387-5472 . They should be able to save you some money on your stuff too.I prefer to install siphons because of cost , but they also do a good job of removing the stagnant water from the lower levels of the pond, where as spillways alone and conventional overflows don't. They should be able to answer any questions about siphons or any of the products they carry. I'm new here but i think this a great site.

I have never understood how the siphon starts. There is a principle I'm missing.

The pipe will fill with water as the pond level
rises. The air openings will submerge and the
siphon effect will occur. The siphon will continue until the water level drops below the
air openings. Then, due to the pipe slant angle
through the dam, the remaining water in the pipe
(below the air opening) will drain out.

Dave, squeeky is correct, but maybe if you keep in mind the pipe going down the backside of the pond will always be longer (to give it the 4 ft lower needed to work correctly) than the pipe going down the front side it may help. The water filling the pipe going down the backside of the dam will always have enough weight to help in the lift of the water in the front side of the pond.
If the pipes were equal in length they wouldn't produce a siphon effect. hope this helps.

Rich and Squeeky. Thanx but I still don't get it. I was raised on a West Texas irrigated cotton farm. We used aluminum tubes to suck or siphon water from a stopped up ditch, over the side of the ditch and into the furrow. It kept running as long as the siphoning end was below water by a sufficient amount.

However, it didn't start on its own. We had to put one end of the tube under water in the ditch; then put most of the rest of the tube in the ditch to almost fill it with water. Next we placed our hand over the furrow end of the tube to create a vacuum and then quickly pulled the tube over the dam with the furrow end lower than the ditch end.

I can understand how a tube/pipe through a dam could start on it's own but can't understand how a tube/pipe can be started siphoning when the top part of the pipe is out of the water. Maybe I need to go back and re-read some stuff.

The principal is the same for the dam siphon
except the system is all in place and nothing
has to be maneuvered. The suction end of the pipe
is fixed below the pond surface, but higher than
the discharge end. When the the pipe fills with
water, the siphon process is started.

So, it would have to be at the overflow area and the water would have to fill the pond and be ready to go over the low area?

Dave,
I don't know if you've seen a pic of the set-up but imagine a pipe of suitable size running from the bottom of a pond up & over/through the dam but lower than the spillway, down the back side all the way to the base. A tee is installed on the top front of the dam in the (main) pipe & a smaller pipe (vent) leaves the tee parallel to the water & turning down 90 deg toward the water. Wherever this pipe ends the water level will be.
As the water rises it blocks this smaller (vent) pipe & eventually rises high enough to start running down the larger (main) pipe. Once this starts it creats a siphon & will continue until the water gets below the smaller (vent) pipe & the siphon stops.
If you plug the vent pipe the siphon will continue until the water gets below the intake of the larger (main) pipe.
Hope this explanation is coherent.