I've been talking to local contractors about the estimated cost to build my pond. The pond will be between 1/4 - 1 acre, depending on cost. I have a site with enough watershed to keep it full. It's on a gentle slope. The people who've looked at it say that it will be a "half dam, half dug-out." Test holes show 2 feet of topsoil, then lots of good blue clay with some shale mixed in. In fact, the contractor who dug the test holes said they're among the best he's ever seen in this area. The extra dirt will be dumped on another spot on my land, around 700' away.

The contractor I'm talking to is quoting the entire job based on $2.75 per cubic yard. What I'm wondering about is that he's basing his estimate on the total cubic yards of water in the finished pond. i.e., if the surface of the pond is 100'x100', average depth of 5', then the water area is 100'x100'x5' = 50,000 sq. ft. / 27 = 1,852 sq. yards. At a cost of $2.75 per yard this means $5,000 for a 1/4 acre pond. If I go up to a larger pond the cost becomes astronomical. It would be around $23,000 for a one acre pond!

I'm wondering if he actually needs to move that much dirt since the land is on a slope and he can build a dam to get some of the height he needs. I mean, it's not like he's just digging a 100x100x5 hole in the ground. Plus, the soil is perfect and he's dumping the extra dirt close by, which I thought should reduce the price some.

Any thoughts? Is $2.75 per cubic yard of water in the finished pond as crazy as I think it is?

I would have that size pond built on an hourly basis only. You contractor is basing the Cubic yards on the dirt being moved...Topsoil will need to be moved twice and the dam will encompass far more area than the water it will hold.

$23K for a one acre pond sounds about double what I would expect, but I don't really know the area rates or what "extra" work is included.

Some threads related cost of pond construction:

Current price per yard for dirt work in N. Texas?

This thread includes some great advice from contractor Eddie Walker:
How much to dig new pond?

We just paid $6,500 to have approx. 2,500 CY of dirt loaded, hauled 3/8 mile, compacted, and shaped to raise, broaden, and lengthen our dam. Remember any estimate is just that, an estimate...and unless the contractor is willing to guarantee the job will not exceed his estimate cost you're stuck with his final "estimate" of how much work he did, etc.

I grew up doing highway construction work, my father was in the business and I worked in it off and on for much of my life. For me, I'd much prefer a turn key bid based on your specifications of the dam length and cross-section. In other words: construct dam 300' long, 15' high, 10' flat width on top, 2:1 slope on front, and 3:1 slope on back or whatever particulars you want incorporated in the project. That can include disposing of "X" CY of material in your selected waste site. Unless you need the dirt in another location it would be cheaper to just "over build" the dam and use it there rather than loading and hauling to another spot.

Unless you have a reputable contractor, hourly work or dirt volume based on a load count can easily become a point of contention unless you're going to be there and count the loads or keep the equipment hours. Again, I'm saying it all depends on the contractor you select, his reputation, and the amount of time you can give to overseeing the work.

With very little effort, the dam can be designed, a few elevation shots taken and a fairly close determination can be made on how much compacted material it will take to build. Based on that he should be able to give you his price for building that dam. That way he can take his time or work 18 hr days, load his trucks heaping or half full...his choice and you'll still know what the final cost will be going into the contract as opposed to not knowing until Pay Day at the end.

Unless I owned or was renting the equipment, hiring the operators and overseeing the work myself I just wouldn't do it any other way unless I was really confident in the reputation of the person I was contracting with. But that's just me.

One other thought...any estimate of cost based on how much water the dam will impound is foolish. That's not what determines how much it will cost to build the dam. All that matters there is do you want to spend X amount of dollars to have a X ac pond. That helps you decide if it's worth it or not.

Sorry, I think I just wrote a book. I apologize for the lengthy post.

Jerry

Thanks for the great information, everyone.

Is there any good way to estimate the amount of dirt to be moved to build a pond of x size on gently sloping pasture land? i.e., is half of the total end water volume a good estimate?

Also, does anyone know if $2.75 per cubic yard of dirt moved is a reasonable cost? I'm in NE Oklahoma.

700 ft to move the dirt costs a lot more than 100 ft.
Using the dirt in the dam area impounds more water and is usually the most economical place to put the dirt.
If a standard dam isn't practical raising the property up on the low side of the pond can normally use a massive amount of dirt.
On yardage just figure the hole to be dug.
I'll try to do a simple example to get a fairly close yardage estimate.
200 x 200 hole 11 ft deep. Ground is sloping 1 ft every 100 ft so 8 ft cut top side, 9 ft cut dam side will give a flat bottom and = 10 ft average cut. Slopes at 3:1 = 10x3 = 30 ft per side average.
2 slopes = 1 cube =
170x170x10= 28900/27=10,703 cubic yds
100 x 100 hole avg 10 ft deep 3:1 slopes
70x70x10=49,000 /27= 1814 cu yds and would have a 40ft by 40 ft bottom
100x100 x 5 ft deep with 3:1 slopes
85*85*5=3625 /27 = 1338 yds
If you could waste the dirt right by the pond and went with the 1800 yd pond I would think you could get a bid for about 50-75 cents less and I would hope that to save and spread topsoil on top of the waste dirt would not be extra.
I would suggest 10 ft depth.
If it's bid use a fixed reference point away from the work to survey from (bench mark). Something like the top of a fence post in a fence that won't be disturbed. Take surface shots and a shot from the bench mark.
If the surface shot is 5 ft lower than the bench mark than the pond bottom should be 15 ft lower than the bench mark, if going 10 ft deep.

Ack, you answered your own question when you said the contractor would build half dam and half dug out for the pond.