Strange Drain Pipe Arrangement in my Pond

[ElmosBoy]

New member,
Been lurking around for a few weeks, since buying my 2555 Mahindra!!!!). I have had some issues with my .8 acre, 7'-14', pond recently and just wanted to ask a few questions to see if anyone can offer some insight. :confused3:
I have an 8" vertical drain pipe that I assumed connected, via elbow to a horizontal 8" pipe that travels under my levy, out to a spill area for drainage. All of that assumption was correct except for the elbow...It ties into the horizontal pipe via a T...AND a ten foot section of horizontal pipe heads back toward the middle of the pond, as well as the 74-80 foot section that goes out to the spill-area. Now for the rest of the story.:confused2:
Had a clog, pond got REALLY high, my wife passed away on 12/17, so I was tied up with other matters & didn't notice until water was covering the deck of my dock. Friend of mine & I begin the process of "Unclogging" the drain pipe. We start from the spill-way end & pvc-pipe/pressure wash back up the length of the horizontal pipe under the levy. We encounter several blockages, (Feel like Blockages) as we push the cleaning device into the drain-pipe. We think we have it working, but the flow of water seems far inadequate for size of pipe.

We take another run at the pipe, just with the pvc push rod & VIOLA!!:cool2: Water comes forth in a big way and the vertical pipe is soon creating a whirlpool!!! :dance1:Life is good, we move on with our lives...
Until 3 days later, my daughter asks why the pond looks so ugly:confused2:....Because it has no water, or almost none...We discover that there is this section of pipe at the T, where the vertical drain pipe is that heads back into the pond...The only thing I can assume is that we managed to knock an end cap off of the pipe, during our cleaning effort, & allowed the entire pond to drain, except for 3-4 feet of water...
I have provided the owls, local coyotes, foxes, & whatever else shows up a smorgasbord of catfish & brim in the wet-lands my pond spills into...But even more importantly, I have to pray for rain & a quick refill of my pond, as it is the broader heat-exchanger in my "Surface Water Geothermal Heat Pump System", & problems heating & cooling my home are inbound if I don't get back some of the temperature exchange media, (Water), I inadvertently drained into the swamp...

All that to ask, why in the world did the Previous Owner run that 10' section of pipe back into the pond, t'ed at the vertical drain pipe??? Was it there to provide for complete drainage by introducing a long & strong enough push, thru the horizontal drain section, (Which I would have thought near impossible to force off against the pressure of that millions of gallons of water pushing back against it)...Or what?? Ideas or questions, I believe I have the pipe recapped, with a make shift cap, (You'd be surprised how few companies sell 8" pvc fittings on a Saturday in Southeast Georgia)...And have regained 10"-12" of water in 24- hours. Again any thoughts would be appreciated, sorry for the novel, but thanks in advance for ideas.

 

[Tonyinohio]

First of all, sorry for your loss. Secondly, welcome to TBN. Curious what was used to clear the blockage on round 2 compared to round 1. I wonder too where the assumed PVC cap went as it should still be in the pond. I would guess two stand pipes since a .8 acre running thru one small stand pipe sounds inadequate. Most ponds in our area have large concrete storm sewer sized overflow stand pipes.

 

[CADplans]

The pressure on the PVC cap is not the pressure of "millions of gallons"

The pressure equates to the small column of water above the cap, so, minimal pressure will remove the cap,,

My neighbor has a sheet of window glass over the end of the "T" on his pond.
The idea was that he could open the "T" with the bullet from a 22 rifle,,, simply shatter the glass.

This was installed before PVC pipe was in common use, his pipe is steel.

 

[Gary Fowler]

Just sounds like poor thought process with that design. I think I would have removed that section of pipe and just used a 90 ell while the pond was drained down.

 

[oosik]

Yes - while the water is low I'd muck out there and get rid of the ten foot section of pipe that goes back towards the center of the pond. End up with just the vertical pipe - an elbow - the section that goes out to the levy. Since there is no understandable reason for this odd ten foot chunk of pipe and it's at the bottom of the pond - I would eliminate it.

I assume you are not able to contact the previous owner and ask - why???

 

[pmsmechanic]

I'm thinking that the pipe setup was designed that way. What you did was use it as designed which was to drain the pond.

 

[Fuddy1952]

Where I grew up, grandfather put in a 2 acre pond. Overflow always getting clogged, so he had a 3ft concrete culvert pipe on one end of dam up about 2ft above drainpipe. Other end of dam is a spillway, goes down around hill.
I fixed the clogging 3 years ago. I took a 55 gallon Rubbermaid trash can, upside down bolted a cement block to bottom, stainless bolts through to 2 angle iron pieces width of can across. This I placed over drainpipe with a helper from boat. I had to drill a 1/2" hole in bottom to do it (let air out).
Water has to enter down about 3ft, up can then down pipe.
Never had a problem since.

 

[oosik]

That's my thought also, pmsmechanic. But there must have been some method to get to the cap and undo it - and then put it back on.

 

[hosspuller]

I'm thinking that the pipe setup was designed that way. What you did was use it as designed which was to drain the pond.

You may be looking for the wrong thing ( a pvc cap) it may be merely a plate or shallow plug that fit the end of the tee. A cap would be hard to dislodge after a few years.

 

[pmsmechanic]

That's my thought also, pmsmechanic. But there must have been some method to get to the cap and undo it - and then put it back on.

What about a flat plate against the end of the pipe with a stout rope to shore. It will take a good pull to start it moving off the end of the pipe.

I kind of don't mind the idea of a piece of glass that gets shot out. Except for the broken glass....

 

[ElmosBoy]

Thanks for all of the comments. It is possible that whatever was used to plug/cover the pond drain pipe was not an actual pvc-cap. I made an emergency repair by placing a make shift cover, (10" diameter aluminum pot w/roofing tar/sticky paper covering the inside of the pot), over the horizontal extension, packed with what may be some of the best clay I've ever seen, and adding some 550-cord leads that were zip-tied to the pipe (You gotta love those H/F heavy duty zip-ties!!). Again, my entire heating and cooling system depends on some water to exchange heat in...We completely stopped the flow of water & looks like I've already regained a little over a foot of depth.

Thanks for the kind words about losing my wife, she had Leukemia & battled it for several years. Was not unexpected, but still you kinda get used to having someone around after 34 years. I have four fantastic grown children & they are helping tremendously as we work thru it.

I think now that I know it is there, & will measure back to my actual vertical pipe before introducing any future "Dislodgement Devices", all should be fine. I also believe, after some reflection time that the vertical pipe is far more stable, mounted in a T connection, supported by horizontal pipe in both directions. Ignorance is bliss, until you drain your pond because of it... I called the previous owner's son, (Gentleman that had this drain pipe installed died several years back, interestingly enough from the same type of cancer as my wife), but the son had no clue as to the construction of the drain pipe. I like the trash-can idea as well, will need some turtle obstacles, at least, for certain. I've been here for almost 6-years & have never had a moments' trouble with this pond...Maybe my wife is "Helping" me stay busy from the other side....Anyway, thanks for all of the thoughts & I agree, we inadvertently used it as it was designed.

 

[Ford850]

I'd take off the new cap and add an elbow and short upright section of pipe, then the cap. That way you can extend that new pipe to the surface if some day you want the second overflow. The new elbow will also prevent anyone from popping off the cap like you did by accident.

 

[ovrszd]

Are your heat exchanger pipes simply laying on the pond floor?

Maybe it was designed as a method to drain the pond to access the exchanger pipes if needed?

As to the size of the pipe. In my country there are hundreds of large structures, many acres in size, that have an 8" or 10" steel drainage overflow pipe. Considerable freeboard built into the dam. An emergency earthen spillway for those hundred year rains. Much better erosion control with that design. After a big rain they may flow water for a couple weeks before the pond gets back to static level.

 

[TractorGuy]

Sounds like the vertical pipe may still be clogged. Most I've seen actually had a valve to drain the pond when desired.

 

[ElmosBoy]

Not a bad idea Ford850, I will seek to secure the required parts...

 

[ElmosBoy]

I installed the Geothermal system, the pipes are on the bottom of the pond, but they travel to & from a Copper Heat exchanger that really lakes the closed loop system work!!

 

[Industrial Toys]

I needed to drain our pond some years ago to install a new discharge pipe and gate valve, and tried running 4" pipe farther out into the pond to thwart the beavers from plugging it up, if it was close to the bank.

 

[Fuddy1952]

Last year we put a little holding pond in a spring here like drawing and used a PVC sweep tee, end capped off. Everything glued except the cap. To drain it once I used a long pole, 10ft sections joined, and a few whacks the cap came off.
Grandfather's lake he used cast iron pipe (lake put in 1954), and a threaded elbow. It's 18ft at the pipe. Lakes been drained a couple times, we just hit pipe with the boat, then pulled it down once started.
Probably the best but not least expensive would be a gate valve.