Pond Boss
Posted By: Laneman Leaking, rotted outlet pipe - 12/25/12 12:27 PM
Hi,

New member with a leaking outlet pipe. I have a 3 acre pond in Texas built on heavy clay. The water retention was excellent until recently, when I noticed water flowing around the outsides of the corrugated outlet pipe. Once the flow stopped I looked in the pipe and saw areas that had rusted through. The soil around the pipe is eroded away, so I basically have a tunnel now. I'm looking for ideas on how to proceed, though funds are limited. Here are some ideas I have considered: I saw a web site that sells poly pipe sleeves that can be inserted through rusted out corrugated pipe. Seems like it may work but I don't know if I could seal the leak around the pipe. I'm wondering if I can pull the old pipe out with my tractor since the soil is eroded away from the pipe, then slip in a new pipe. Another idea is to fill the pipe in and let the spillway handle the overflow. I imagine the best repair is to dig out the old pipe, I just don't have the funds for a backhoe repair. What do you guys recommend?
Posted By: esshup Re: Leaking, rotted outlet pipe - 12/25/12 02:27 PM
Welcome to the forum!

Unfortunately, you know the best way to fix the problem, all you lack is funds. If you end up going that route, don't forget to add anti-seep collars.

I'd look into the sleeve for the next option. The only suggestion that I have to seal the outside of the pipe is to dig down and pour cement or bentonite around the outside of the pipe as close to the pond side of the pipe as you feel comfortable digging.

Going the "pressure grout the leaky pipe full" and let the emergency overflow handle the now normal overflow isn't recommended at all. If it's the standard grass covered soil overflow, there's a very good chance that the increased water flow will slowly wear it away and cause the whole dam to fail.
Posted By: fish n chips Re: Leaking, rotted outlet pipe - 12/25/12 02:57 PM
Welcome to the site, and Merry Christmas. Although your pipe makes it not so merry.

Definately agree with esshup on the spillway.

How deep below the full water surface is this leaking pipe? In fixing this situation, I would look into a siphon/drain pipe to replace what you have now. Unfortunately any proper fix is going to take money.
Posted By: Laneman Re: Leaking, rotted outlet pipe - 12/25/12 07:21 PM
The pipe has a riser, top of riser is about a foot below spillway. I haven't measured down to bottom of riser elbow, I estimate riser is about 4 or 5 feet tall. The culvert I.D. is around 16", length is around 30 feet. On back side of dam it's about 7 or 8 feet from top of dam to bottom of pipe. Top of riser is in the face of the dam, basically a hole with a cage around it where water falls down into riser. Will try posting some photos


Description: Outlet exit
Attached picture Outlet exit.JPG

Description: Inside culvert
Attached picture inside1.JPG

Description: intake
Attached picture intake2.JPG

Description: outlet erosion
Attached picture outlet erosion.JPG
Posted By: esshup Re: Leaking, rotted outlet pipe - 12/26/12 12:35 AM
Let me guess. Older than 25 years?

Please tell me that you don't have trees larger than 4" diameter growing on the dam...........
Posted By: Kelly Duffie Re: Leaking, rotted outlet pipe - 12/26/12 04:23 AM
This may be a rotten suggestion due to my unfamiliarity with such matters. But, would a temporary fix be possible by bisecting lengthwise a new section of identical corrugated pipe (of the same diameter) and securing/sealing it in position over the rusted bottom of the old pipe (using rivets, sheet-metal screws, adhesive, etc)?
The half-round pipe-section could be inwardly compressed (using temporary draw-wires) to permit its insertion within the old pipe. Of course, adequate access to secure & seal the upstream edge of the half-round might pose a challenge - but I think it is do-able with a little thought. Wonder if there is some type of adhesive that would hold the bisected length of pipe in place (possibly using two or three scissor-jacks to apply internal pressure while it cures).
Go easy on me! It was just a thought! wink

EXISTING

PROPOSED


Posted By: esshup Re: Leaking, rotted outlet pipe - 12/26/12 04:29 AM
Good idea Kelly! It might buy him a few years providing that that area that is shown is the only area with holes in it.
Posted By: FireIsHot Re: Leaking, rotted outlet pipe - 12/26/12 11:00 AM
I hope some metal guy chimes in on that Kelly. That's a great idea for a quick cheap save.

I have the same issue on a couple of dry pipes. Rust out happened after less than 10 years.
Posted By: Laneman Re: Leaking, rotted outlet pipe - 12/26/12 02:05 PM
I think after all the research I'm leaning towards two fixes, either sleeve it with a poly pipe liner and grout each end, or replace the pipe.
Posted By: fish n chips Re: Leaking, rotted outlet pipe - 12/26/12 02:05 PM
Kelly-I like the idea too. I have always liked when people start "thinking outside the box". The biggest obstacle in that would be getting some kind of sealant deep into that tunnel ( I think he said 30'?) and then getting the new pipe to stick good enough to it so there isn't even a hairline crack. Possiblly several jacks inserted deep into the tube would work like you said. To bad there insn't a fluid that you could just pour down the tube and let it settle out level and turn solid AND seal to the pipe. Then you wouldn't have to worry about even putting in additional pipe.

Another half baked idea... Would it be possible to insert a flexible drain pipe down and thru the old pipe all the way to the outlet? Seal of the inlet end so water can't get between the old and new line, forcing the new pipe to be used. This would only work if the old pipe it isn't rusted out at the pond side and the leak is happining after it goes into the groundwork of the dam. Bad news to this would be the new line is smaller than the old one, possibly causing the spillway to be used.

Laneman - Are we to assume the pond is now draind down to the horizontal level of this old pipe?
Posted By: Kelly Duffie Re: Leaking, rotted outlet pipe - 12/26/12 03:32 PM
Originally Posted By: fish n chips
The biggest obstacle in that would be getting some kind of sealant deep into that tunnel ( I think he said 30'?) and then getting the new pipe to stick good enough to it so there isn't even a hairline crack.
What about applying edge-beads and spots of "GREAT STUFF" Pond & Stone to the underside of the half-pipe before inserting it into the old pipe???? Then, use several scissor-jacks positioned atop 2x4s to apply downward pressure along the half-pipe's length while the polyurethane expands and cures. This adhesive would practically "weld" the pipe-pieces together.
This solution could also be used to seal the gap between the old pipe and an inserted pipe-sleeve - if that option is preferred. Attach a 10' length of 1/4" vinyl tubing to the can's discharge nipple to allow fluid-injection well beyond the inlet-pipe's perimeter.
Definitely wear gloves and old clothes when using this messy stuff - but, as the name implies, it works "great".
Posted By: Ghostown Re: Leaking, rotted outlet pipe - 12/26/12 03:45 PM
I know one way they fix old chimneys is to run an air bladder down the middle then pour (concrete or sealant) mix in there. Once cured enough they just remove the air bladder. It would reduce the flow through the tube a little though
Posted By: Kelly Duffie Re: Leaking, rotted outlet pipe - 12/26/12 08:11 PM
Originally Posted By: Ghostown
I know one way they fix old chimneys is to run an air bladder down the middle then pour (concrete or sealant) mix in there.
I could see that technique working within a vertical hollow structure. But, in a horizontal pipe, gravity would pull the sealant to the bottom of the cylinder - which would then push the air bladder to the top of the cylinder. Not necessarily a bad effect in this particular case. However, a support-membrane would be needed to prevent the sealant from draining through the exit-pipe's perforations.
Posted By: Laneman Re: Leaking, rotted outlet pipe - 12/27/12 03:35 AM
I found a web site which has examples of culvert repair methods currently in use, some similar to what you guys are recommending
http://www.udot.utah.gov/main/uconowner.gf?n=1128117589169310
Posted By: fish n chips Re: Leaking, rotted outlet pipe - 12/27/12 02:41 PM
Good find Laneman. It will take awhile for me to read thru all that. You initially said that you wanted a low budget fix. You will want to figure out what might be the cheapest "fix" of them and then get a qoute from someone to see what it would cost to redo the whole thing over the right way. Any repair to the old one seems like it has limited life. I still feel the siphon drain is the way to go for the ideal overflow pipe. Others can comment on that, because I do not have one, but REALLY WISH I did. I found Pond Boss to late for that part. The line thru the dam is not buried down deep into the core of the dam so if there are any future problems with it would not drain your hold pond. You put that in and seal off the old one. Gotta wonder what the cost of that is versus the cost of a repair that will last ten+/- years. How's the rest of your dam condition? Trees on the dam?
Posted By: Laneman Re: Leaking, rotted outlet pipe - 12/28/12 04:26 PM
I do have a few trees, planning to remove them.
Posted By: esshup Re: Leaking, rotted outlet pipe - 12/28/12 04:54 PM
What size are the trees (diameter), and when you say "remove them", what does that entail? Just above ground, or above and below ground?
Posted By: Kelly Duffie Re: Leaking, rotted outlet pipe - 12/28/12 04:58 PM
Originally Posted By: fish n chips
Any repair to the old one seems like it has limited life. I still feel the siphon drain is the way to go for the ideal overflow pipe. The line thru the dam is not buried down deep into the core of the dam so if there are any future problems with it would not drain your entire pond. You put that in and seal off the old one. Gotta wonder what the cost of that is versus the cost of a repair that will last ten+/- years.
Jacked from a previous overflow thread ...
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