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