Ideas for cutting heavy steel pipe under water?

[Perry Holbrook]

Recently bought some land for new home build. It has a farm pond that needs some clean up work around the edges and beavers have stopped up the 4" steel overflow pipe, causing the pond to overflow along the lowest shore edge. So far I have used a combination of pumping water out and digging a small drainage ditch to lower the water level. Not exactly sure where the overflow pipe is, still can't see it, it may even be in the beaver den.

Once I can find and unstop the overflow pipe, the pond will drop to the top of the pipe, which is good, but I want to drop it maybe 12" more. There is not enough fall for a drainage ditch to do that and the 2"trash pump drops the pond slowly. Then of course, all the rain we have been getting doesn't make it any easier.

I would like to figure out a way to cut 6-12" off the top of that 4" heavy wall steel pipe under water. The under water part has me stumped, other than a very difficult hacksaw project. Of course, I do have a small boat.

Thanks for any ideas.

Perry

[Bryan Lisowski]

I would think a cutting torch would be your best bet, unless you can rent a pump that will remove almost all of the water. If your not going to remove the beavers, you should put some sort of screen or cap to stop from getting blocked up again.

[Dan Hunkele]

Go watch a few videos on YouTube for "pond siphon"

https://www.youtube.com/watch?v=8lXl7tdJ7iY

[Malcolm McLeod]

Wait for a drought?;)

Or, build a coffer dam around the pipe (once located). - - A wood box; open top, hole in the bottom to slip over pipe; seal the pipe-wood gap temporarily, pump the water out (box WILL want to float = plan ahead), box is big enough to work a cordless recip saw 'inside'. Cut off desired pipe length. Pull box out.

Or, use a 18"-24" drill bit to 'angle' drill enough holes in the pipe to either break it off, or enough holes to keep the pond level at that new point. A lot depends on the inflow to the pond.

I know there are torches/welders that are used underwater, but would have to Giggle for sources.

[Bill Dufour]

A pipe cutter should work fine underwater. Just dry and oil it before returning to the rental stores. Use a manual one not a power cutter. You will have to have 2-3 feet radius all around the pipe to swing it. Or use a 3 cutter wheel one and only need 60 degrees of arc swing.
Bil lD

[Myk Rian]

You want the level lowered by 12". That means lowering the dam wall, and pipe 12".
I don't see where cutting the pipe off will do anything.

[Jay Michaels]

Would it work to simply drill a bunch of holes around the side of the pipe at the level you want -- not even so you can fracture off the top of the pipe, but just so pond water can drain into the pipe through the holes?

[Perry Holbrook]

Go watch a few videos on YouTube for "pond siphon"

https://www.youtube.com/watch?v=8lXl7tdJ7iY


Thanks for all the ideas, some I hadn't thought of. I had thought of the siphon idea, but had discounted it for some reason, don't remember why. That may be the first thing to try.

[George Yetka]

My guess is that it isnt steel, probably cast, Steel would have rusted out pretty quick. I would use a ratcheting snap cutter if it is in fact Cast iron. Cast will kill drill bits and torch wont work on it either.

[Lisa Starr]

Perry,

Is this a vertical overflow pipe or horizontal. You see both in our neck of the woods. Since you're talking about shortening, I'm assuming it is vertical. What is the water source of the pond? Can you dam the inflow and then pump it to lower the level?

[Bruce Wrenn]

Can you get to outlet of the pipe below the dam? If so, get a "Drain King, and using a hose from pump or house, inflate it. The vibrations will break up the obstructions, allowing water to flow. Just be prepared for a SUDDEN burst of eater when you take the pressure off the drain king. For a filter box on top of overflow pipe, consider a "milk crate." Any kind of cutter you may use to cut pipe needs to be FASTENED with a rope, tied off to something that won't sink. If you decide to siphon pond, reduce the outlet end from 4" to 2" to prevent air from "gulping back into siphon pipe. Each spring, local "Y" drains pool (380,000 gallons) for servicing. They used to pump it out (a week), till I showed them how to siphon it (48 hours.)

[Bill Dufour]

det cord?

Bill D

[George Yetka]

Do you have a picture?

[Perry Holbrook]

Perry,

Is this a vertical overflow pipe or horizontal. You see both in our neck of the woods. Since you're talking about shortening, I'm assuming it is vertical. What is the water source of the pond? Can you dam the inflow and then pump it to lower the level?

It's a vertical pipe, that could be cast. We think the pond is 40+ years old. Not sure of the water source, maybe a spring, but about a dozen acres of open land slopes toward the pond, so it could be just ground water. Neighbor says he's never seen the water level drop.

[Perry Holbrook]

My guess is that it isnt steel, probably cast, Steel would have rusted out pretty quick. I would use a ratcheting snap cutter if it is in fact Cast iron. Cast will kill drill bits and torch wont work on it either.

Didn't know about this tool. I see Home Depot rents them. Probably the ticket if it's cast.

Thanks

[Perry Holbrook]

Do you have a picture?

This was taken before I started pumping and dug the drain ditch. You can tell where the pond edge should be. The overflow pipe is somewhere to the extreme right.

Just a side note, once I get the level dropped so I can clean the edges, I plan to bring the water level back up to this level and hope to raise it as much as another foot, requiring this overflow pipe to be altered anyway.

It was used as a farm pond but I hope to make it look more like something you would see on a fine golf course.

[Bill Dufour]

There are two kinds of pipe cutter the chain ones for cast iron and the wheel types for steel pipe. The link is a large one for steel pipe. I have one like it I need to get rid of.
Bill D

https://www.unitedrentals.com/marketplace/equipment/plumbingpipeconduit/pipecutting/pipe-cutter-hinged-8-12#/

4" pipe use this one instead

http://www.arvadarentalls.com/rental-product/pipe-cutter-(2-4-inch)---ridge-tool-co/3932 (https://www.unitedrentals.com/marketplace/equipment/plumbingpipeconduit/pipecutting/pipe-cutter-hinged-8-12#/)

[Bruce Wrenn]

If you have a boat, pipe can be located. On rear of boat, make a loop of chain, which doesn't have to be very heavy duty. Fasten one end to one side of boat, and other end to other side. Row back and forth till chain snags the pipe. Have something in boat, such as a piece of 3/4" PVC, then rod the pipe from above. Many ponds were built with a drain valve installed at base of overflow pipe.

[michael langman]

If the pipe did not have water flowing down it, could you cut the pipe from the inside out if it is vertical?

[Tom M King]

Air powered reciprocating saw.

[Jim Matthews]

det cord?

Bill D

"Hold my beer."

[Perry Holbrook]

An update for those who are interested. We found the outflow pipe at the base of the dam, it is cast. We plugged the pipe with a rag and used compressed air from a small portable tank to pressurize as best we could. Saw a few air bubbles come up on the surface of the water and found the overflow about 6" under the surface. Unplugged the beaver patch over it and drained to the design water level.

The siphon idea looks like the best option of taking the water down another 12" or so, which is the nest step. Then use that ratchet snap tool to cut off the intake pipe, and use my new tractor/backhoe to make the needed repairs to the pond banks.

Thanks for the suggestions, it was a big help . I did check on the det cord, turns out you need a special license to buy it, imagine that!

Perry

[Myk Rian]

I still don't understand cutting the pipe. All that will do is raise the minimum controlled level.

[Perry Holbrook]

I still don't understand cutting the pipe. All that will do is raise the minimum controlled level.

The pipe is vertical, down to the bottom and then turns 90 degs under the damn coming out outside the base of the dawn. It's used to provide overflow protection for the pond. By making the vertical height of the pipe shorter, water flows into the pipe and out of the pond, setting a new maximum pond depth.

My intention is to eventually plug this pipe completely and put in a new overflow/spillway at a higher level. Hope to raise the water level about 18" total after I repair and reshape the pond.

Perry

[Dan Hunkele]

Thanks for the update. Good to hear you got the clog handled.

[George Yetka]

In that case I would get out there and snap cut 18" off (assuming straight pipe) and let it drain. Then once the repairs are made use a stainless repair clamp and reconnect pipe with a strainer basket on the end. you may have to clean it out every few years but it will keep the pipe from ever clogging

[George Yetka]

you can rent a mud sucker or a trash pump to move the water if you have a place to send it. They usually have a 3" hard rubber suction line and a roll of light duty fire hose on the discharge and can move water easily

[Gary Ragatz]

I still don't understand cutting the pipe. All that will do is raise the minimum controlled level.

Myk,

In this type of pond, the top of the overflow pipe is well below the height of the dam that creates the pond. This is to keep the water from flowing over the dam itself (and causing damage/erosion of the dam). When the water level reaches the height of the overflow pipe, the excess water flows through the overflow (usually under the dam itself) to keep the water level at the desired maximum level. Cutting the pipe lowers the maximum level of the water.

It's like the overflow in a bathroom sink. When the stopper is in the drain, if the water gets too deep, it runs out the overflow (bypassing the stopper) instead of overflowing the top of the sink.