Pond Boss Forums INTRO Questions & Observations Rusted out Stand Pipe

Hi all,

What a great wealth of information, glad I found this Site!

I am in the process of purchasing a tract a land in East Texas - It has, (or more accurately "had") a rather nice 8 or so acre lake on it. Upon close inspection I can see that the pipe rusted at about the L-bend, where the pipe runs under the dam. The Stand pipe is inside the dam.

Questions:

Is having the standpipe inside the lake a recommended replacement design? Do I have a choice?

I have been told - "don’t dig up the dam to replace the pipe, it will never seal properly". Instead, "shove a new pipe through the old one and pump fill the excess space in the old pipe".

I have also been told - "repacking the dam is not a problem with the correct fill and proper equipment."

A third option presented was plugging the old pipe and installing a "vaccum breaker" PVC system.

Any thoughts? I am rookie - but feeling like I am already hooked.

darnold,

What do you mean the standpipe is inside the dam? Does this mean the water flows over a lip on the dam into the stand pipe?

I am Cunfused.

The stand pipe design is like this one (except there is no slide gate):

http://www.ponddampiping.com/conv1.html

The pipe is rusted where the Riser Tee meets the first section of outflow pipe.

W. Roberson,

Thanks for the reply - I see your logic here. Thats sounds reasonable - leave the dam in place (no large scale digging) + put Syphon System (at a lower cost) rather than replacing the old stand pipe system. Is there any othere advantage to Syphon vs Stand Pipe? I assume you can drain your lake with a Syphon system as easily as a stand pipe?

Dan

W. Robinson,

After searching through this board and reading your post, I have to agree. My primary concern will be "plugging" the old coorigated pipe...and making sure the new siphon system is installed properly.

Any recommendations on filling the old pipe? concrete?

Is there an article or guide for sizing the pipe on a siphon system? I have an airel survey of the lake at capacity and have plotted it out to be approx. 1,375 feet length (both sides are aprox equal)and 475 feet across the dam. It is a basic long triangle shape. I did some rough math and came up with about 7.5 acres...can anyone confirm this?

Thanks for your information!

This is the first of many issues for this lake...I suppose this situation it is common - it has not been cared for and will need a lot more work to get it into shape.

Your watershed area is more of a determining
factor than pond area in determining siphon
pipe size. I have a 12" siphon system on a
pond with 165 acres of watershed and a second
pipe is probably needed. NRCS can advise you
on this. Be use you have good emergency overflow
areas.

Some of the other concerns are;

- dense vegatation and timber around the northern half of the lakes old shoreline. AKA, you cant walk around the lake. The growth is far too dense.

- trees growing on the dam (not sure if I can do anything here). I suppose I should trim them and leave them in place?

I am weighing is wether to "clean-up" the above issues at the same time I have the new drain put in, or wait and see what happens after the lake fills...if anyone has experience in this area I would love to hear about it.

Dan

squeeky,

In looking at the topo map in the link above - seem like its about 250 - 300 acres of watershed.

I come up with 7.38 acres for a triangle with those dimensions.

What else needs to be considered for calculating the size of pipe? The lake at capacity is roughly 7.5 surface acres and the watershed is about 250 - 300 acres.

:p

darnold,

I hate to see a good overflow go to waste.

What is the size of the riser and drain pipe?

Can you manipulate a pvc pipe enough to glue an elbo? If not, you may have to use threaded steel pipe. When I was much younger I drilled water wells (using a spudder rig). You should be able to find a local driller that can install steel piping and elbos in any hole.

Perhaps try lowering a short riser steel pipe with a pre-installed elbo to the drain pipe level and then thread into the elbo from the the drain pipe area.

With either pvc or steel, I would put a riser on the elbo to at least 18 inches above the break and fill the void with mortar to about 15 inches, leaving a 3 inch lip.

Before pouring the mortar, you may want to have some stuffing on hand to pack around the drain pipe exit if mortar finds its way that far which is not likely.

After pouring the mortar, pack it as best you can, let it dry an hour and then fill the lip with clean water and keep water on the fresh cement for at least a week. Cement cures best under a layer of water. If possible, I would then dry it and fill the three inch lip with a sealer, perhaps hot tar, perhaps some new stuff that may be available.

If this does not work, cement the sucker, fill almost full and keep a four foot deep pit in the stand pipe to keep a supply of minnows on hand.

Here in Oklahoma, I would be very concerned that a 350 ac. water shed going to an 8 ac. lake is going to flood big time after every rain. You need a method to drain down the lake.

The reason a drain down is a good ideal is to keep a reserve available to catch large rains in your area. Fish farmers generally recommend a three to six inch reservoir depending on the amount of rain expected in the immediate future. A drain down is also good for draining down in winter to kill off shallow weed growth ( if you get a freeze that far south).

I like the ideal of installing a syphon system for drain down. It does not have to be really large and I would not let it extend much below six or eight inches below overflow level just in case you forget it is open or something goes wrong with any level control you have on it.

Due to the large water shed, be sure you have a proper emergency overflow area spread evenly over at least a fifty foot grassy area with a gentle slope. You may want to fence the emergency overflow to keep your fish in the lake.

By the way, sorry you got hooked. You may want to get a second job to support this new habit, I mean hobby.

Good luck.

Dennis,

Thanks for the insight; you bring up a couple of points I need to consider. The riser is about 36”, the drain pipe is at least 24", perhaps it is 36” too. I am going down to measure it today. I will take some pictures too.

The original construction has all of riser AND most of the T-joint exposed in the water as opposed to being buried with only the top portion of the riser exposed to water. The rusted spot is just behind the T-Joint where the drain pipe meets the dam. In my case the entire riser and t-Joint can be easily removed since they are exposed

On reuse of the old pipe - it seems reusing it may be more costly than capping and sealing it based, on the folks I have been talking to...I think threading a new pipe can be done easily enough - it's the sealing part that is the wild card. The contractors I spoke with say there is a 50% - 75% chance of getting a good seal with a new pipe inserted through the old one. I guess air pockets and seepage around the seal are potential issues. On the other hand, they feel the success rate for capping the old pipe is 100%. I am meeting 2 contractors to let them have a look at it and make suggestions too. My (personal) issue with reusing the old pipe (other than cost) is that it is rusted in one spot now and may be just a matter of time before it fails somewhere else.

One issue I will address for sure – the new system will drain from the bottom as opposed to the current overflow style.

You bring up a good point about the watershed and possible overflow issues. I have a call into my local NRCS office - I am hoping the can provide the watershed acreage and water flow data. I don’t recall seeing a proper spillway – but hey, I hadn’t found PondBoss.com yet and didn’t know what I was supposed to be looking at!

My to-do list is getting longer and longer. I AM HOOKED.

darnold,
I fixed a pond that was very similar to yours in January. The stand pipe was rusted and leaking letting the water level drop. Also the spillway was in bad shape.
I dug out the old pipe which was rusted badly also and installed a new pvc pipe with 3 anti seep collars. No stand pipe.
Cleared behind the dam and repaired spillway.
Here we have heavy clay and sealing the dam back up is not a problem. Extra dirt is beneficial so repair can be over built a foot or so.
Lowered the water level from original level and raised spillway to try to lessen the water through the spillway.
The pipe was just over 2 thousand and so was my equipment time.
It's a cattle pond and will require no maintenance for many years with normal rains.

Kent,

Thanks for your reply.

I am assuming the repairs made are holding up fine. It is good to hear that this can be repaired successfully.

I had 3 contractors give me 3 very different opinions. 2 are well known "big time" businesses that do a lot of utility and oil field contract work in the area. The 3rd is an independent self-employed engineer type. I have seen examples of all of their work - they all seem to be capable and have been referred to me.

The 2 big contractors gave me BIG estimates and repair recommendations. IE Tear out the old pipe lay in a new one - basically rebuild old system, but using new (expensive) steel pipe, big crews and lots of equipment. Made the whole deal seem like a big job. Both of these guys are asking $25 - $30K for the repair.

The independent engineer suggests digging out the old pipe about half way through the dam, then and quickly refilling and packing old hole. My dam is about 80 feet wide at the point where the pipe goes through. He would dig about 30 feet Into the dam from the water side, pinch off the old stand pipe, then start packing back out with clay. He will install a siphon valve system at a new location on the dam. Total price for the repair is about $5K. He has been doing this type of work for 40 years and claims to repaired 50 dams in a similar way. He also said if it leaks he will fix it at no charge and he will put that in writing.

That big of a $ difference in price makes me wonder why? I feel the Big
Contractors are doing what big contractors do - which is big jobs. When I asked one about a siphon system he said, “those are the ones that leak”. I asked why and he said you could not use PVC successfully “because there is no way to put a seep ring on it”. That seems wrong. It sounds more like he prefers using steel instead of PVC.

Assuming the independent is reliable and knows what he is doing, I’m going with him. I went by a friend of mine’s place and saw a pond this guy built last year and the work was holding good, no problems and he cleaned up the place really neat. My land has a lot of red clay; I am assuming that it is good quality clay for building dams… It is good to know others have successfully replaced stand-pipes.

I’m sure of 2 things, neither of which is that my repair decision is 100% fool proof. 1. I’m hooked - I can already envision the 8.5 acre lake full (of water and fish) and me fishing on it and 2. This is the first of many “projects” on this lake.

I plan on posting updates on my progress. I have a few pictures if anyone is interested email me – I would appreciate any suggestions before I start drawing up contracts for the work.

Dan,
Maybe they need a new pickup. I do and if could get that much to fix a couple of dams I could get one.
How your guy wants to do it is basically what i did. I dug out the old riser and several feet of pipe with a couple swipes with the big excavator. Put a coffer dam there to hold back the water. Dug out the rest of the pipe. Filled and packed dirt in up to where we wanted water level. Then installed pvc pipe inlet to the side of where the old pipe was at on existing fill. This pvc was 18 or 24 inches, can't recall, heavy stuff with gasketted joints. Used the 6' by 6' rubber anti seeps that you cut a hole in and run the pipe through the center of. Cut the hole tight and it leaves a rubber lip all the way around the pipe to clamp tightly with a couple of long hose clamps.

Kent,

Yeah, maybe he needs a new pick-up truck and a new dozer.



It sounds like your install is very similar. Are anti-seep rings a requirement on a vacuum system? I am assuming that the pipe is at water level. Seems like gravity would get the water before it had a chance to get to the rings…maybe not. On second thought, the cost is probably very little, maybe better just to put them on anyway – just to be sure.

Thanks for input; I’ll let you know how it goes.

Dan

Dan,
I haven't done a siphon system yet.
If I was to cipher... water wouldn't try to follow the siphon pipe as bad, due to it lying for a ways flat at water level.
Where the typical pipe running downhill in the dam is going the way water likes, downhill.
On the typical installation 3 is common, I would suggest at least 1 on the siphon.
The pipe I installed was 18", very heavy stuff.
And the job is holding fine.

Hello all,

Thanks for your input here. I thought I would add an update to my stand-pipe issue.

I received some valuable advice from Meadowlark on another post - come to find out, this lake does not have an Emergency Spillway. They built the dam with a 6’ riser - I suppose they got lucky in that it has never over-flowed.

I have decided to combine the 2 issues to solve my rusted stand-pipe issue. I am installing a new earthen emergency spillway + eliminating the existing stand-pipe and adding a new 12” Siphon System. The spillway will give me the run off capacity I need and the 12” pipe will give me the control I need at a lower cost than replacing the current 24” system.

Photos of leaking pipe:

http://i4.photobucket.com/albums/y117/darnold01/Standpipeleakcloseup2.jpg

http://i4.photobucket.com/albums/y117/darnold01/Standpipecropped.jpg

So far I have learned if contractors “smell” an opportunity they will bid it up. AKA, the dumb big city guy (me) coming out to the country must have lots of money to spend mentality. I had 3 bids; $32,000, $25,000 and my last bid $5,500. The $32K and $25K bids were only for fixing the leak. The $5,500 bid provides the fix above + clears all the brush off my lake, takes the trees off both sides of my dam, repairs roads + installs a new bridge in a washed out creek. WHAT A DIFFERENCE! The guy who bid $25K ball-parked the same work for $50K - $60K + he wanted to “re-do” my dam for up to $100K total.

My low-bid contractor started last week and it is obvious that he knows how to do dirt work. I figured at worst case if he does all the above work and if the repair doesn’t hold – I can still hire someone to repair the leak and I will still come out ahead on the total price.

Thanks PB, I will update as the work is completed.

I am now working on a survey and have a post going in corrective stocking.

Alligator,

Way to go! You are on your way...but remember its a journey, not a destination. Let us know how it goes.

I found this old thread, but it had great info. Also, at this point, you can probably tell me if you went with the siphon system (at lower cost vs replacing the stand pipe) and most of all - whether it worked and you are happy. I would appreciate any insight you could share. Thanks in advance.

Hopefully you will get an answer. The last time Alligator posted was in 2016.....