Pond Boss Forums POND CONSTRUCTION Renovating a Pond or Lake? Can we make it deeper, Dad?

Hi everyone,

I�m in the early stages of managing a 50-year old, 4-acre pond in Oklahoma, and the lack of rain over the past couple of years has gotten me more interested in increasing the �normal� water level. The primary goal is to increase the odds that during such extended drought conditions, we�re retaining enough water to sustain the fish population. The secondary goal is to make it deeper just because that�s what I want.

I�m contemplating the best way(s) to accomplish this; your ideas and opinions would be appreciated!

We all like pictures, so I will take a shot at including some photos and providing some background to set the scene�


This pond is the result of a pretty good-sized dam (33� elevation, 50,000 cu. yd. soil) that was constructed jointly by local authorities and federal Soil Conservation Service as a flood prevention project in 1966.

The surface area is approximately 4 acres, average depth perhaps 4 feet, max depth 11 feet and plenty of 2 feet depth at the upper end of the pond where much sediment has wandered in over the years. (There are also two other secondary inlets that have carried a lot of sediment in; all noted in photos below.)

The photo above shows the pond at approximately 3� below �normal� water level. Also illustrated by arrows are points where substantial amounts of sediment have accumulated creating much shallower areas; and one arrow highlighting the large distance between primary spillway and top of dam. Additionally, you can see the length and height of the dam itself.

In the photo below, the slopes at these two locations are vastly different� just can�t see it very clearly here.


The original SCS design of the dam and primary spillway specified 19 feet of freeboard; as built, I believe the actual distance is 17 feet.


Recently the original spillway riser and drain valve were replaced, having rusted out. The metal riser was replaced with heavy walled polyethylene pipe, along with a new gate valve and corrugated steel crown. (See photos.)



The new riser is positioned at same elevation as previous one, with 17 feet of freeboard.


And as you can almost see in the pic below, the drought last year has caused water level to recede well below the drain valve (still have 5 feet of water depth in some areas; 12 inches in others).


I believe the pond basin is basically a smooth bathtub shape, and the opportunity to completely empty the reservoir and re-work the bottom would be enjoyable. But between cost of doing so and the current good quality of fishing, pumping out the whole thing is not currently on the radar.

So� if a person wanted to increase water depth in this pond, how would you recommend that be accomplished?

Look forward to hearing some great ideas! Thanks, in advance, for your input.

Sounds like you need rain first of all

Maybe I don't understand something here. But, is there some reason that you can't extend the riser to get more depth before overflow?

My thoughts were the same as Dave's.

Has the lake ever risen above the riser during very heavy rains? Looks like the house in the second pic may be below the top of the dam, and raising the water level may create an issue with the that.

I've also used wire reinforced construction site silt fences in several areas that helped with catching the run off silt, and they are relatively inexpensive. May be worth looking at if new silt is still a problem.

If it was feasible, I'd pump the pond down some, maybe removing 25% of the water, dig out the accumulated sediment in the areas that are above the reduced water level, and add to the riser. If the dam is supposed to be 2' higher, could that be raised as well, and the emergency spillway raised at the same time? That should take care of the immediate sediment problem. I would dig as deep as feasible providing there isn't sand under the pond bottom.

I would look into constructing silt settlment ponds where the water enters the pond. It'd be easier to clean out the smaller settlment ponds on an annual or bi-annual basis than having to try and clean out the large pond.

DVR......If this project was built "by local authorities and federal Soil Conservation Service as a flood prevention project in 1966", are they still responsible for the upkeep of the dam?

BGKiller, your insight made me LOL! I'm told we did actually get a couple of inches a few days ago...

Dave/Al, I was skirting that issue of extending the riser because as Buzzworth touched on, the local NRCS is responsible for maintaining the dam. Getting approval to modify the piping design that was developed by federal agency in 1960-something would be painful, I think. (I've floated that idea once, and it wasn't encouraged.) Or would it be easier than i think?

And Al, yes indeed, when we get big rains the water level gets several feet above the top of that riser. And yes, you are correct about the cabin being exposed to flooding... but it's just sitting on blocks and not too difficult to move.

Soooo, I was hoping there might be some other approaches that are obvious to everyone but me!

esshup, i like your idea of partially emptying the pond, and then digging out what sediment we can. I'm guessing that the only real way to know if there's sand below is either coring or just dig away... is that correct?

thanks to both of you for the thoughts about the settlement ponds. I don't have much space on my property upstream of this pond, but it could be feasible. That'll have to wait till I can get back there and study it.

Any other ideas? I have plenty of time for planning.

- DVR