Pond Boss Forums POND CONSTRUCTION Building a dam Dam size to expand an existing pond.

Hi, I am new to this site but have visited a few times and enjoyed the reading, lots of good info.

So I have a question regarding an existing pond on my farm. The dam is about 7 foot high and was put is about 50 ft long and about 20 foot wide at the base and about 12 ft at the top ( can easily drive a truck out on dam. ) I will measure and get more precise measurements.

The pond sits in a ravine and for over a decade has been empty as the over flow pipe broke off, however I fixed that. When full I estimate the pond was about only 1/8th of an acre. I have quite a bit more room however to expand the size up the valley/ravine. One side is fairly steep where storm run off has cut into the bank of the pasture in this ravine/valley while the other side tapers up much more gradually.

I'd like to make the pond close to an acre but am not sure if the dam then needs to be enlarged to hold that amount of water.

The area I am in and doing some digging is largely clay so that is good and making the dam higher is fairly easy however I am not sure of the width since it will hold back water over a relatively narrow area and back it up the valley/ravine. Below the dam it is all woods/rocks and opens up into a an ever larger valley/creek but no houses etc. Still I do not want a failure of the dam.

Any good suggestions to get started? Also I will be doing the work myself with a skid loader and backhoe so I won't be consulting a contractor likely since I just want to enlarge the pond to have a nice place to fish.

Thanks for any thoughts.
( any necessary calculations for volume of water to dam size etc ). Pond area drainage is about 20 acres, and overflow pipe is a 15 inch pipe currently with spillway. I can pump out any water while I expand up the valley. )

I can tell you that if it was me I wouldn't want to invest the time and money into a project like that without getting some expert on-site advice. Others smarter than I will comment here but like I've read on this forum - there's a big difference between digging a hole and making a pond.

First thing that comes to mind would be "did the original constructor cut a good key and compact the existing levee to be able to withstand the pressure of all that water". If not just adding dirt on top of and around the back/sides won't last - it could push right through the existing levee portion.

Right, hard for me to know for sure. It was constructed in the mid 1990's as part of a township ROW issue. That is a sub-contractor for the twp made the pond. I know the conservation office was involved so I would hope they had some oversight of the project. My father was here and I was living away and dad is passed now so I am not sure. I have no data as to what they did and only saw a small portion of it being made.

So that makes it tough. Now it does not have to be one acre in size. In fact that might be a bit much, especially as you point out without some knowledge of how it was built and what it can handle. It might be wise even that I let that pond alone and build a larger one above it perhaps since and I'd know what I have as far as the new dam and leave the small pond alone. I could stagger two ponds or several ponds up the valley. I have seen this done on a golf course where I once worked, looked good. I would need some help of for sure.

I am going to get some measurements and see what exactly I have and then post those.

Talk to the people at your counties NRCS office.

Ok, after some further measurements I'd be pretty content with making the pond about 100 ft longer. So it would be about 60ft wide by 200 ft long making it about a quarter acre instead of a 1 or even half acre pond. That would give me the room I'd like to have for the spot it is in and look pretty nice.

Again, I have can't know for sure how well the dam was built back in the mid 90s. But adding only an 1/8th of an acre won't stress things like making it a 1/2 or 1 acre pond. The dams base is 28 ft wide and tapers up to 10 ft wide at the top. I have no way of knowing how solid it was made only that we had a permit for the pond to be built and there were some conservation folks involved due to the farm.

Any good ideas on who/what I might want to do before I enlarge the pond? Again I am now only wanting to add an 1/8th of an acre and of that most of it will be 5 ft deep tapering up to a shallow 1 ft or less.

Thanks in advance. Great site. I am new but am already learning a lot.

Lbm in PA.

Silly question as I have already made a few posts on here. But how do you start a new post? I obviously found it once but can't seem to locate how you do that this a.m. I am interested in renting some equipment vs buying it.

Thanks again!

LBM.

Log in...

Go to the Forums section where you have all those categories to view. Click on the area you think your question would fit the best. In the upper left area you will find a button for "New Topic".

You can find this button at the top of any page under "topic options". However, I think it will place your question in that part of the forum, which might not be the best place for it.