Hi all, we are in drought mode again this year, which might be turned to my advantage...
My dam was reconstructed several years ago by someone else and only has a spillway for drainage. Problem is, the spillway has eroded and is unsightly. With the water being so low, I have been tempted to install a pipe for overflow (if we ever overflow again!!), but, I would sure hate to screw it up worse. Please look at the photos at: Dam/Spillway pics and advise.
The standpipe is useless as far as I can tell, other than it still closely represents spill level. I have some 12" pvc that I can use. The "plan" right now would be to bust out the existing concrete, trench for new pipe, install a tee with extension below (drive the lower part into the pond bottom, maybe a foot or two), adjust the height to spill level, connect the horizontal drain part on a slight tilt, then bury the pipe to match the rest of the dam.
That would be the first and main part, after that I can consider piping and burying the rest of the drain down to the lower pond.
Any ideas, tips, etc are appreciated!
Thanks,
Dob

I would suggest that you take a look at a spillway syphon system.
You wouldn't have to weaken the dam with this type of system.

Interesting concept, George. I had not heard of that (or just plain ignored/forgot!) kind of system. Is this link what you mean?
Any other suggestions?

Thanks again,
Dob

Yep, that's it.
Easy to do yourself - just a couple of 22 1/2 degree 8 inch joints and 8 inch tubing - cut a 3 inch hole in the joint at water level and that's about it. When the water level reaches the hole it will syphon the water from the deep area at the dam.

Guess your 12 inch tubing might work - we used 8 inch and it handled a 9 inch rain with no overflow at emergency spillway.

Dobber,
I tried and failed to email you pics of our syphon system - goofey computer says invalid adress.
If you'll email me texoma@wans.net to confirm your address, I'll try again.
george

Thanks George,
email is on it's way...
Not sure about the address snafu, I copied from my profile to a test to myself, it worked OK.
"Goofey Computer", I hope...
Dob

George,
Thanks for the pics!
A couple of questions - I don't see a siphon relief pipe like in Detail "A" of the diagram at Siphon System , how do you "turn it off".
And, did you not bury the sloped pipes for a reason, other than ease of install? I was thinking of putting a turned up end into the pond as well as on the outlet end, to keep it from sucking up any sludge.
It did, of course, rain here today...
But, just a drop in the bucket, literally!

When the water level covers the hole in the joint at top, syphon will begin. When the water level drops below the relief hole, it breaks the suction automatically.
I'm sure the relief pipe as shown, will do the same.
The pipe is buried at the top and on the backside of the dam, exposed where it empties into the creek.
george

So, just so I understand, you don't have the upside sown "u" shaped contraption, but rather a hole on the top of the flow pipe, on the water side.

That "u" shaped thing worried me a little, seems like it would be an eyesore as well, but I suppose it would allow for a complete burial of the flow pipe, and the over flow stage could be somewhat regulated by the height of the open end... I think I like the hole idea better.

Thanks again for all of your help & pics!

Hey,
Could you post the pictures of your siphon system. I am looking at doing the same type thing and would love to see the pics.

Scott,
I will email the pictures.
george

Scott & Dobber,

I completed this installation on my 5-acre pond using two 8 inch pipe systems side-by-side. Since my pond filled last Sept, this system has handled all rainfall & watershed totally - the emergency spillway has never had water cross it yet - and there have been several storms where water was pouring through these pipes big time!

Unfortunately I don't have any pictures I can post. I've yet to try the manual siphon function to see if it does drain the pond down on demand. I'm fairly sure that will work as well.

I did a lot of research before construction, & must admit, for the money, this is the best spillway system I found. By drawing out the bottom (dead) water instead of the top water, it is healthier for the pond & keeps your fertilization in the pond instead of going out over the spillway. I would recommend installing this system (as shown in the diagram) highly.

Best of luck!

Dobber, Since you are in GA you should give the folks at pond dam piping (Macon) a call. I've always ordered my fittings from them for all the siphon systems I've helped install. I'm sure since they are a paid advertiser in POnd Boss they would appreciate it. For other folks asking you can see a diagram of the siphon system at their website. www.ponddampiping.com
Good luck, Greg www.lakework.com

Greg: Beat you to it! I just got a reply email from Keith Harris at pdp, very helpful!

Stuart: do you ( as in the diagram ) use the relief valve (?) as in the diagram?

I would think then, that 8" would be (more) than sufficient to handle my 1 acre LAKE.

I installed my pipes exactly like the diagram. As I said, I've yet to try to manually draw the pond down using the siphon function. I do have pictures but not a scanner nor the knowledge to get them on here for you, Donner, unfortunately.

I would think one 8" system will work fine for your lake, but run it by the pro's at PDP to be sure.

Hi all. I live downstream of Dobbers pond and am afraid this dam could burst any time. I posted images for you to see for some knowledgeble input. Thanks! [img]http://home.bellsouth.net/p/s/community.dll?ep=16&groupid=233088&ck=[/img] [/IMG]

I can't seem to get the link for the pics here so try this link by copy and paste
http://home.bellsouth.net/p/s/community.dll?ep=16&groupid=233088&ck=[/IMG]

Click the photo gallery link for pics. Again, any feedback is welcome!

I am in process of constructing a 2.5 acre farm pond in upstate NY. The siphon system looks like a very good idea and I considered it for awhile as an emergency overflow spillway, but I began wondering what would happen in winter time. When the pond freezes with ice up to 3', the plug of ice lodged in the tube at pond water surface height would render the spillway siphon tube inoperable. We periodically get winter warmups, rain & snowmelts while the ponds are still frozen over with a couple feet of ice. I would think that in the 'hard winter north' an old fashion riprap spillway in the berm is the way to go. Has anyone tried this siphon system where winters freeze over the pond surface ??

Just so y'all know... the dam is/was never in danger of bursting. Lack of adequate vegetation caused some erosion of the freeboard. Pappy & I got together (like neighbors should) and added enough dirt/clay such that the height is better than a foot higher than the lowest point elsewhere in the freeboard. Now, we're both happy - I get a better looking and better sloped lee side and Pappy gets to sleep better when it rains!