Digging a pond with a backhoe

I plan on digging a pond this summer...
I have been searching for info on using a backhoe and all of the postings are concerned with getting rid of the dirt, but what if?
What if I dig a trench around the perimeter of the pond and use this dirt as the levee? A way to visualize this is as you approach the pond there is the levee, or in my case a berm, the just past the berm in the pond, there is a deep trench - dirt use to build the berm levee, and then the pond becomes shallower -- maybe 5-6 feet deep.
FYI the land is nearly flat and is heavy clay to at least 14 feet deep.
Thanks.
I hope I articulated my idea so that it's understandable...

Phillip:

Paul advocates something like this for berms.  Digging a moat and piling up the dirt is a very efficient way to construct a big berm.

BUT a berm is just holding itself up, and isn't holding back water!    By digging around the outside perimeter of the pond you are effectively undercutting the ability of the soil to act as a dam.  Better to dig the pond into the terrain b/c then you have ALL of the surrounding terrain acting as your "dam" and the probability of it failing is really low.   Taking the diggings and making an extra berm/dam around the pond is an economical way to increase the volume of the dam - but its just increasing the volume, not being the primary means of restraining all that water.

A drawing would be helpful .. but well, I'm relaxing right now.

Is it a hole on flat land?
Most of our ponds are built in gullies and the dirt/clay is used for the dam wall.
There is one dam that was built on almost flat ground and the wall/berm is made from the diggings.
Seems to work OK.

Drew Moffatt wrote:Is it a hole on flat land?
Most of our ponds are built in gullies and the dirt/clay is used for the dam wall.
There is one dam that was built on almost flat ground and the wall/berm is made from the diggings.
Seems to work OK.

Very flat. The area where the pond will be built slopes down gently. About 2-3 feet lower than the surrounding area.

Eliot Mason wrote:Phillip:

Paul advocates something like this for berms.  Digging a moat and piling up the dirt is a very efficient way to construct a big berm.

BUT a berm is just holding itself up, and isn't holding back water!    By digging around the outside perimeter of the pond you are effectively undercutting the ability of the soil to act as a dam.  Better to dig the pond into the terrain b/c then you have ALL of the surrounding terrain acting as your "dam" and the probability of it failing is really low.   Taking the diggings and making an extra berm/dam around the pond is an economical way to increase the volume of the dam - but its just increasing the volume, not being the primary means of restraining all that water.

A drawing would be helpful .. but well, I'm relaxing right now.

I see your point. Might be better to rent a dozer and push up a levee from the center of the pond?
Then again, I have seen ponds where they brought in clay and formed a levee without digging out at all. This is VERY heavy clay. The call it "gumbo" around here.

Phillip Pace wrote: Might be better to rent a dozer and push up a levee from the center of the pond?
Then again, I have seen ponds where they brought in clay and formed a levee without digging out at all.

I'm not an expert on the dozer vs backhoe vs excavator question.  You could use a backhoe to dig out the center of the pond, although I'd allow that another tool might be better than a backhoe.

Regardless of the soil composition, that gumbo is coming from somewhere.  Unless you have another excavation project that is generating excess material, I'll posit that the critical issue is one of efficiency - and its more efficient to dig a hole and use the burden as a levee than to leave the pond bottom untouched and build up a levee.

In my area, I can dig ponds without paperwork.

I can't legally build dams above a very small capacity without engineering paperwork. The risk of damage in case of a blowout is considered too high.

There is a LOT of force in that water!


Do you have a spring, or expect enough ground water for the dam walls to add to retained capacity? Or are you trying to store winter water into summer?



I have a friend who has a real nice pond, he told me about having it put in.

He picked a central spot on his property, I have no idea what it was like before the pond went in.

Then he had the equipment brought in. A big dozer, a medium dozer, and a fullsize excavator.

I do not know if he cut a keyway for the berm/dam; certainly he should have.. but the bulk of the pond was dug with the large dozer down in the hole, digging itself deeper and deeper. The excavator lifted this loose material up to the edge. The smaller dozer drove in circles around the outside compacting and probably a spreading the lifted spoil.

He told me it took around a week with all 3 machines. Getting the compaction done well seems like a real hassle without at least 2 machines running..

There is a bit of seepage out one side, through or under the dam, but it holds water, noticably above the level of the surrounding fields, right through our usual summer droughts. His property is near some big forested hills and has several small springs, though.

Eliot Mason wrote:

Phillip Pace wrote: Might be better to rent a dozer and push up a levee from the center of the pond?
Then again, I have seen ponds where they brought in clay and formed a levee without digging out at all.

I'm not an expert on the dozer vs backhoe vs excavator question.  You could use a backhoe to dig out the center of the pond, although I'd allow that another tool might be better than a backhoe.

Regardless of the soil composition, that gumbo is coming from somewhere.  Unless you have another excavation project that is generating excess material, I'll posit that the critical issue is one of efficiency - and its more efficient to dig a hole and use the burden as a levee than to leave the pond bottom untouched and build up a levee.

I agree. The question seems to be how much levee is safe. I know that water produces a lot of pressure, but here in Louisiana, 3-5 foot levees are common.

D Nikolls wrote:In my area, I can dig ponds without paperwork.

I can't legally build dams above a very small capacity without engineering paperwork. The risk of damage in case of a blowout is considered too high.

There is a LOT of force in that water!


Do you have a spring, or expect enough ground water for the dam walls to add to retained capacity? Or are you trying to store winter water into summer?

Using winter water to store into summer.



I have a friend who has a real nice pond, he told me about having it put in.

He picked a central spot on his property, I have no idea what it was like before the pond went in.

Then he had the equipment brought in. A big dozer, a medium dozer, and a fullsize excavator.

I do not know if he cut a keyway for the berm/dam; certainly he should have.. but the bulk of the pond was dug with the large dozer down in the hole, digging itself deeper and deeper. The excavator lifted this loose material up to the edge. The smaller dozer drove in circles around the outside compacting and probably a spreading the lifted spoil.

He told me it took around a week with all 3 machines. Getting the compaction done well seems like a real hassle without at least 2 machines running..

There is a bit of seepage out one side, through or under the dam, but it holds water, noticably above the level of the surrounding fields, right through our usual summer droughts. His property is near some big forested hills and has several small springs, though.

How big is his pond?

Phillip Pace wrote:
I agree. The question seems to be how much levee is safe. I know that water produces a lot of pressure, but here in Louisiana, 3-5 foot levees are common.

Code generally seems to be that if you're building a dam above a certain height (8'-10'?) OR if the area of the pond is greater than some lower limit (1/4" acre?) then the DAM needs to be engineered, stamped, approved, etc.  So yeah, a 3'-5' levee isn't a huge threat to yourself or neighbors.

I think D. Nikolls is on the right track ... its a difference of digging a pond or creating a dam.  Water is happy to remain in a hole, while water would really prefer to not be in a dam (yes yes yes, I'm grossly simplifying physics there).  Thus Digging a pond is a lot simpler, less technical and far less prone to failure.

Deep ponds are generally better than shallow ponds - the depth creates cooler water, provides multiple climate zones, less loss to evaporation, etc.  So you want a pond that is much deeper than any dam you can build.

Giving the description of the area ... flat with a slight slope of 2-3' - I'd suggest a deep hole with just a 3' dam.  It will blend with the landscape, be a WIDE (safer) dam.

There's also the question of sealing the pond.  Without getting technical ('cuz I can't - I've just read not done...) having a bulldozer or other steel-tracked beast IN the pond really helps to seal it.  Going back to the original question of just building a dam, that pond bottom wouldn't necessarily be worked and might not seal as well.  A whole lot of "might" and "helps" of uncertainty there.