Pond Boss Forums POND CONSTRUCTION Building a dam Do siphon systems work well?

I'm referring to something like CWJ recently posted.

http://www.ponddampiping.com/syphon1.html

I have no experience with, nor have I ever seen one of these systems. How delicate are these systems to place? What is the cost vs. a standpipe? Would you recommend caps or valves? If valves, are there any particular types of valves that you have had good experiences with? When starting the siphon to drain the lake down, what type of vacuum pump is needed? Are there any drawbacks to this type of system?

I'm sure I'll think of more questions but would appreciate any feedback.

I like the fact that you would not have to have a hole through the core of the dam.

There's nothing delicate or finicky about siphon systems. Depending on the head... the height of the pond above the outflow... they can really move some water.

When used for an overflow, a pump is not needed. A properly designed siphon will start and stop on its own at the right time.

To draw down a pond, the siphoin may need a pump assist to get it started. Any type of water pump will work, even a very small one. I used a small hand bilge pump, and it worked great. For drawdown, it's important that the pipe joints and valves are absolutely air tight. Otherwise, the siphon will slow down and eventually stop flowing.

Bobad,
Is the siphon system I linked to the one most people use? On that link, it states something about the water being 20 feet deep or less. Will this be a problem if my water is 25 feet deep at the dam? Do you have any drawings or pictures of the one you used? Thanks.

cm, are you doing it yourself?

No, I'm contracting the job out. The NRCS agent will help in planning and overseeing the project.

Many folks have siphon systems and there are slight differences from builder to builder from what I see - however the overall concept is basically the same. They do work and will maintain a proper level in the pond if done designed/installed correctly. Some siphon designs allow you to drain the pond. All designs that I see pull water off the bottom or at least some distance below surface level.

I would recommend an emergency spillway in addition to a drain (siphon or otherwise).

I think for some of your posts - Pond Boss has good information + Bob Lusk has a book you should read. Additionally, selecting the right pond builder will be a critical step for you. Make sure you get a pond builder, not a dirt mover.

The NRCS should have a list of local builders, check references. Go see their work.

Thanks Alligator. That's good info. I will definitely make sure I get a pond builder. I have been reading a lot on this forum about the siphon systems, but I didn't see any information on which systems were more popular. And I will definitely have an emergency spillway.

Good Luck cm,

Some folks like the idea of siphons, some dont.

The link above is a good example to use, IMO.

(added) The size of pipe plus other factors will determine how much water the system will move (additionally - something to think about) larger pipe equals higher cost. The size of pond, watershed, average rainfall and other factors will determine what size pipe you should use. (Maybe) your NRCS person can help with that?


Here is an interesting link on pipe flow rates too: http://www.sahra.arizona.edu/programs/water_cons/resources/pipeToFlow.htm

happy reading!

Good point. Another factor is, the bigger the pipe, the harder it is to get perfect joint seals.

If simply used as an overflow, a few pinhole leaks in the joints won't hurt a thing. If used to draw down the pond, pinhole leaks will slow the siphon down, and eventually stop it from flowing. It will drive you bonkers to keep re-starting the siphon.

That's good information guys. I appreciate it. The things that are important to me: no hole through the core, overflow device and being able to draw the lake down. It seems that these siphon systems are the best way to go. I'll do more research but the information leans heavily toward a siphon.

Siphon systems do work very well. One of the ponds at my deer lease as a siphon in it. One time when the siphon was going the holes in the top pipe got clogged and kept the siphon running. The pond has not been full since. Whatever type of siphon you use MAKE SURE YOU HAVE A TRASH GUARD. Now the siphons have wire cages around them, so hopefully it won't happen again.

I have two 12" siphons in my pond. The normal flow only spills through one of them, and a good rain will flow through both. I don't believe they have ever gone into true siphon mode. I am very happy with the way they work so far. I am looking forward to seeing what a 12" siphon can do, though. I bet it's a sight to see.

Jersey, how big is your pond. The contractor that's going to build my girlfriend's 6 acre pond is planning on installing two 8" siphons.

My pond is 6 acres, with 320 acres of watershed. The watershed is more important than the pond size.

Ah. Cindy's pond has a watershed of only about 60 acres. Sounds like we're good, thanks.