Hey Board,

Been doing a lot of research and talking to a lot of engineers/consultants regarding my options. Given how much the permitting process would be here in VA, the idea of constructing a new pond appears cost prohibitive. I've had multiple experts quote me $25k minimum just to get through the county, state, and core of engineers (wetlands..).

Fortunately, I've got a silted in, 50 year old farm pond that is grandfathered from all these permits. At first, I was told it couldn't be expanded by a consultant. I then had an engineer look a little deeper and thinks we can increase from 1/2 acre to 1.25 acre....which is perfect! Total cost...probably 50Kish.

My question. The pond will need to be drained, and dam expanded and raised. The current dam has no valve, no pipe, it just has a run off on the side that controls the height.

I'd like to drain in myself to help reduce the cost of construction. Ive read siphon would be best. Ok. Once it's drained, should I hire someone to cut a trench in the dam so it doesn't fill back up and can dry out??

50 k seems way too high for 1.25 acres. My advice is do not cut the dam unless you have a way to compact it back. We cut my pond's dam to drain out what we could in August 2015, and could not pack the trench in properly after/during renovation, resulting in a leak. If I had a do over, I would just use a trash pump.

In order to get the pond bigger, the dam needs to be enlarged, extended, and raised. There is currently no pipe/drain system. I'd like to do it right so I don't have to go back and do it again.

I guess I could see if they could increase the size of the dam without cutting it. I'm no dirt mover.....so I have no idea

A lot of silt/muck has to get pushed out too. Hoping to drain the pond and start drying that stuff out..

i have used those cheap chinese trash pumps and they work fine.

I would use a trash pump. It will be a pain to keep setting it up, but I think that would be best. However, I would consult the guy who going to do the work. He may plan on cutting it open anyway ( which I would question the guy's pond ability at that point). 1/2 pond would drain quickly with a 3 to 4" trash pump. You may want to dig a pit for the suction hose to be below the mucky level. That will be the only way the muck will begin to dry out, for the water water to flow into this pit out of the muck.

I am a little concerned for you about the water supply for a bigger pond. You say that there is no real overflow on the current pond. This tells me that rains rarely fill it up enough to need a regular overflow system. How will you get more water to fill a bigger pond?

I have a hard time seeing how pumping a pond out will allow it to dry. It's still going to hold water and try to fill up even a little with every rain keeping your muck wet. My biggest fear while renovating my 1/4 acre pond was that we would get half the muck out and a good rain would come and cover the remaining muck with water leaving my pond unfinished and filling back up.

We cut the dam below the muck line with a mini excavator to drain and then widened the cut with the track loader as the muck was hauled/pushed through the wide cut. Dam was cut in May and muck removal started mid September. When we got down to the last few feet of muck we stopped cutting the dam deeper as the weather forecast did not call for any rain for what was left to dig out (a day or two). Once the muck was removed, we dug good clay from the far side and refilled the wide cut in the dam compacting the best we could as we went. It looks great, BUT it's not filled back up yet due to the lack of rain. My guy is a "dirt man" with many ponds under his belt. So hopefully his 30 plus hours and my $3000 don't end up as an expensive leak. Keep in mind that my little pond has many times the amount of watershed than it needs and will fill up with a few 3 inch rains.

If you have a "silted in" pond, it would cost 4 times the price of bucketing out muck over cutting a breach in the current dam. 50K sounds about right for moving silt and rebuilding/expanding/raising a dam....it will take a LOT of earth being moved.

A siphon is by far the fastest, lowest cost method of draining a pond, but the total "lift" is a limiting factor. Using 4" (or even 2") schedule 40 PVC and rubber connection couplers makes a temporary siphon easy to build. Also, a complete renovation would be the perfect time to install a permanent, well designed, bottom draw, automatic start/stop siphon that will nearly eliminate future silt issues forming in the future. If you are prepared to spend around $50K, plan, plan, plan, and don't cut corners to save the most dollars!

The cut in my dam was narrow and cut with a back hoe. That's why we could not compact it well, and maybe part of the reason I still have a leak. If you cut the dam with a dozer, and make a wide, shallow v cut, you should be able to compact it back with wheeled equipment. With our latest pond, we used a 20,000 lb backhoe with a yard plus of dirt in the front bucket to compact the entire basin and rather shallow dam.

Edit: My old 1/4 acre pond renovation including removal of 5 feet of muck cost under $2,900 and construction of the new 1/4 acre pond which is about 60% excavation and 40% dam cost just under $2,800. Neither have piped spillways, as watershed is limited, and I have creek water available about seven months of the year.

Rainman, I just read your post advising the following and will doubtless have more questions for you on this very subject.

You wrote: "Also, a complete renovation would be the perfect time to install a permanent, well designed, bottom draw, automatic start/stop siphon that will nearly eliminate future silt issues forming in the future."

My pond has a bottom drain that the drain pipe plugs into. From what I understand, that pipe can simply be pulled straight up and the pond drains out. What do you mean by a a permanent, well designed, bottom draw, automatic start/stop siphon that will nearly eliminate future silt issues forming in the future?

Please explain. This coming March a neighbor heavy equipment operator is going to completely redo my pond. I am, of course, VERY curious of how to circumvent future buildup of silt, if possible. Thanks for any helpful info! I included a photo from Today after letting the pond refill from having it drained 2 feet lower.

Another photo of a closeup somewhat of the drain pipe configuration. The pipe extends about 4 feet below that screw-in drain plug in the vertical pipe. I capped the 45 degree section so it would fill up and drain in from the top. Please correct me if I was mistaken in doing that, but a top drain is all we had in our pond when I was a kid. That pond was 15' deep.

If it matters, the pond refilled back to the top of the pipe level in 96 hours easy. There are several feeder springs into flowing into this pond, and it NEVER freezes over. Coldest water temp all winter was 45F degrees.

Lastly, there is a third photo showing what the pond looked like after unscrewing the side drain plug in the vertical pipe.

Question here: Why would the water level only drain to half way down the opening? Is that how fast the inflow is compared to outflow? Shouldn't it drain all the way to the bottom of the screw-in drain plug shown?

From my best guess, there is at least 1.5' of pure organic muck covering the entire bottom of this pond, accumulated in about 15 years from the previous excavation clean-out. That is a primary reason I am having it dug out (again).

Chuck

Hmm. No replies? Is this thread even looked at anymore? I sure could use some advice, and this is the most relevant thread I found on draining a farm pond to rework it. I can't cut any new dam to move muck out, as there isn't a dam right now, only a drain pipe with several springs with GREAT output to keep quite a flow.

The decent amount of flow through this pond is why I can't use natural muck-eating products, as they would just wash through.

I want to drain my pond to have it dug out, but I have a BIG concern as per a neighbor's comments on my pond. He said he would not dig as deep as I wanted (15') as he'd hit mancos shale, resulting in a leaking pond. There is at least 2' of heavy muck across the entire bottom. Making the pond only about 6' deep, and too warm for most any fish to survive in it at 66F degrees all summer.

He said 10' might be okay, but he also said he recommends against removing all the muck layer as it is an important sealing layer keeping leaks from happening.

Does the anti-leaking layer of muck claim have any merit? If he doesn't want to dig it out, I can find someone who will do it, but no doubt for more $$.

The neighbor is a very accomplished heavy equipment operator, and has dug several of his own ponds, so I put some weight to his words, but not complete confidence.

I hope to hear back real soon. I'd like to pull the drain tomorrow (Easter) to begin to let it dry over the next month or so, and have it dug out.

Thanks all and Happy Easter!
Chuck

I am doubtful that the muck is sealing the pond. Did it leak before the muck formed? It is hard to tell where the organic material in your pond is coming from. If it is washing in from the watershed, can you install a settling pond to intercept the inflow?

Chuck, with a water temperature of 66°F all summer long, trout will live in the pond all year long.

I would use a 3" semi trash pump to drain the water from the pond, and cut steps in the side of the pond to place the pump as close to the water level as possible as the pond water level drops.

I would dig a test hole to see what the soil is like at the different depths, that will allow you to determine how deep to dig the pond. If you run into clay, stockpile it to put back in the pond bottom and compact it with a sheepsfoot roller to get good compaction. Don't plan on getting the proper compaction with the tracks from the excavator or from the tracks on a dozer.

Thank you all VERY much for your feedback! Sure is draining slow thus far after two hours of taking the stand pipe out of the bottom drain pipe connection. We'll see tomorrow if anything has changed. It was easy to keep it open when the stand pipe was in place, but I'm a little concerned now as I cannot see the bottom pipe opening to make sure it is not blocked, potentially resulting overflowing.

...Always something.

Looking forward to more progress on this pond. Good things take time, I know.

If you DO have to unblock it, be very, very careful and unblock it from the outlet side, not the inlet side. If you get sucked into the pipe, or part of your body gets sucked into the pipe from the inlet side, it could get very messy very quickly..

Thanks esshup, always a treat to have your input. Well, ya know what? I pulled on that blasted pipe for a good bit, while my Honey's son Ben held onto my lifevest while he was on shore to not let anything too bad happen. I could not get the pipe to lift all the way free of the inlet at the bottom without any leverage, so he went into the pond himself. It took his full strength to hug it and pull it up. Then he scooted the few feet to shore quick, and crawled up on land without incident at all.

I am mainly replying to your post to say the pond seemed to drain for a moment, then stopped draining much at all. A trickle of about the same amount as its usual flow seems to be what the case is right now. So it is not overflowing but is not draining either.

Incredible that with as phenomenal of force as that much water pressure creates, whatever is blocking the outlet can actually withstand it. I intend to find a gas powered water pump (or air?) to attach to the outlet and blow out whatever is impeding the flow, which, yes, I know, is exactly what you recommended to do anyway.

I was also thinking to try to find the inlet with a long small diameter pole, e.g., long aluminum pool cleaner pole to see if I could just poke whatever it is through the pipe inlet. Absolutely no change has occurred in water level since yesterday when the pipe was pulled, except for that little bit at first that I mentioned.

It irritates me that I did not know there was a second side drain screw-in drain cap several inches from the bottom of the vertical drain pipe that we pulled out yesterday. Had I known that plug was there, I'd have just unscrewed that first before yanking the whole pipe - MUCH less likelihood of plugging a side drain hole than a very bottom hole. Oh well. Learn as ya go.

Again, many thanks for any and all input helping me become a wiser pond steward.

A few sticks sideways over the top of the pipe, with a wad of leaves will block it pretty good.

Okay, what now? I was really hoping the top of the drain pipe at the bottom was LOWER THAN IT IS. Rats. There is still about a foot or two of water in the pond, and yeah, I know. A trash pump is the ticket here. I need to channel the springs feeding the pond directly to the drain so more can dry than just the banks all around it.

At the very least, I want to get a little trackhoe to clean up all around the edge of the entire pond to get rid of all the thick weeds and grass. I know it will all try to grow back in time, but for the meantime I'll provide fish habitat eventually when I get it to that point. I think a small trackhoe should fit on the narrow bank okay

I am PLENTY OPEN FOR IDEAS OF ALL SORTS ON WHAT TO DO NEXT WITH THIS POND. If the photos don't indicate it well enough, the pond really is only about 6 feet deep to the top of the muck.

I mainly wanted to get photos up here to get feedback and suggestions. Ideally, it would get dry enough to dig out. That will be complicated as the bank is mighty narrow between the pond and the neighbor's dirt driveway.

For any helpful input, MANY MANY THANKS AND GREAT APPRECIATION FOR THE ADVICE.

DC, any progress? I can't help but think that getting the rest of the water out will require, as you know, a trash pump and plenty of muddy trips into the hole for proper placement of the suction line. Once the lowest spot reveals itself, you may try digging a pit there, lining it with a half barrel to keep the pit open. The barrel would likely need to be peppered with drilled/cut holes and a weed barrier mesh wrapped around its outside to keep the sludge from filling the barrel, but still allow water to get in. I have not done this by no means, but its the first thing I would try if I was not able to get the big boys in to scoop it out wet. All I really know is that muck is very sloppy, a lot like quick sand I'd imagine, very hard to shove and control.

Your pond does not look to be too big, there are medium to large bucket hoes that could make the reach and scoop out the soupy muck which may be the only way if you can not keep water from running into the pond. You will need to eliminate any springs or gullies from feeding the hole or your muck will remain wet. The muck that was pushed over my dam last October still pumped up and down as I drove my 8N tractor over it in early April. We had a dry winter, but the pumping muck was about 10 feet deep on the back side of the dam. The stuff hold water like it was meant too.

My pond was renovated in August 2015. The bulldozer and backhoe came the same day I finished pumping and draining it to the top of the muck. The dozer started on the high side opposite the dam and worked toward the dam. The backhoe was set up on the lowest side of the dam and dug a pit there for the dozer to push muck into. The backhoe would toss the muck from the pit to the back side of the dam. The soil below the muck was much drier and the dozer could get traction by digging through the muck. The dozer finally worked all the way to the dam and the muck was out and somewhat spread. This plus the clearing of trees and brush took about two days on my less than 1/4 acre pond. The third day was spent in shaping and making the pond to be a full 1/4 acre. It had about 5 feet of muck in the deepest part and little at the edges.

The muck took about 11 months to dry enough so it could be spread further and shaped out to one side of the dam, which made the dam there much less steep on the back side. It is now heavily grassed and you would never know it was once pond muck. Fresh pond muck being pushed out has the look and consistency of wet concrete (that never sets up).

Thanks fellas for your insightful replies. Quarter Acre, the recent progress included putting the drain stand pipe back in place to allow the broken pipe locations downstream to dry out enough to replace them more easily and cleanly. So, for now It's filling back up in the meantime. I can drain it anytime very easily once I come up with a better plan. It REALLY helps to know the top of the drain pipe with the stand pipe removed is NOT on the absolute bottom of the pond.

As for the "muddy trips" to move the pump intake, I'd put a rope on it same as I have on the diffuser at the bottom. This makes it easy to move it, allowing me to stay safely on dry land.

The pond is about 95' x 76' x 8' deep. The depth obviously depends on just how thick the muck really is. As you can see in the photos, it is all very steep (vertical, actually) all around except a little slope at the south end where the smaller tree is. These dimensions calculate to approximately .17 surface acres total.

You're right, not very big at all, but still a GREAT opportunity to provide high quality habitat for all kinds of critters here, e.g., fish, wildlife, farm animals, PEOPLE who want to swim, etc. Right now we have goats as our livestock, and when it's drained drink from a spring I dug out to provide a drinking pool for them.

Ideally, I would be able to dig down where the drain pipe is already, and shorten the height to as low as I can to install something like what you described. Somehow I'd have to keep it clear enough of debris falling into it while doing that.

I just looked up the maximum reach on large CAT excavators and it looks like they max out at just shy of 40' reach. This means they would have to be able to go along the hill side of the pond, not the driveway side where, as the photos show is way too narrow for anything but a mini excavator. Of course, another critical deciding factor of ALL Of this project is good 'ole cost.

Again, thanks for any and all input here. I REALLY appreciate every bit of it.

Another question here...

So, I have the pond drained down to the upper drain hole in the stand drain pipe and am most curious if cleaning off all around the entire pond with a mini bobcat excavator will render me ANY benefit at all to this pond. I will physically remove all the FA that just showed up recently, and hit this pond as hard and fast as I can with any natural measure I need to in the lifelong effort to minimize algae. I know attempting as full removal as possible of ALL algae is not a good idea, I get that.

So, question here is: Would removal of all vegetation at the water's edge (grass clumps, cattails, etc.) provide any benefit? The construction of the pond banks does not offer any fish an easy opportunity to make any breeding beds near shore, as I've seen created by countless sunfish-family of fish in other ponds with gentle sloped banks.

As always, many thanks to all who respond with helpful insight here.

What is your #1 goal for this pond?
You mention several things, with both swimming and livestock too. In my opinion, you really only should do/achieve one of those two things.

With your set-up/location of the pond, it looks like choices will be very limited. If you go with livestock area, I think your muck and sediment build-up will be fast. I would dig the most accessible area deeper with a slope towards it,. doesn't matter that you can't reach all of it. The muck will tend to slide towards the deeper end you dig. Then every few years, have it cleaned out in that deeper pit area. Have the area where you can get an excavator and then be able to pull a truck in next to it. That way muck goes from pond to truck with one step. Haul away somewhere else onto your property and repeat as necessary every few years. Initially, you might even have to landscape some spot around the pond to be able to this. but then it will be done for future cleanouts.

The other option is to install a new siphon drain that is set-up to pull water out of the deepest part. Then when the pond fills and flows, it will pull out the muck with the moving water from the bottom. It looks like you have plenty of drop around the pond to achieve a good siphon drain. Not sure if you would be allowed to drop that directly into the road ditch? They might not like the amount of silt that comes with it, however if you had no pond there, that erosion would end up there anyway.

Fish 'n Chips, thanks for your helpful reply. #1 goal for this pond is hard to identify that easily. It is many-fold, i.e., simply to have a healthy little BOW right here below the house for us to enjoy aesthetically; to be able to fish and swim in. Stock watering is a given out of it, but it doesn't affect the water quality in the slightest. Only a few goats do not create much for any issues here, and for hay reasons, we're considering going down to two goats total for the winter. A quick note of this particular BOW: I haven't measured gpm input yet, but there is so much fresh water flowing through this pond it negates any biological additive measure for algae control for example.

I don't know if swimming in this pond will become a reality any time soon. That will require a GREAT deal of digging out I expect, as nobody would want to let their feet drop down into mostly Godawful smelling grey clay mud/muck that resembles glue more than anything.

You are very correct in that where/how my pond is situated seriously limits options for modifying it much. I imagine difficulty in having a sizeable excavator at the north end, where the solar panel aerator system is. That is the largest area nearest the drainpipe. So, if the deepest part of the pond became instead nearest the paved road on the south side (right side in photo), would a siphon drain really suck muck to the drain pipe on the other end of the pond?

How long do you think it would take to drain muck as you describe? If only a matter of hours, I could lay a big pipe across the neighbor's driveway along side the pond and best case scenario let it fertilize our pasture on the other side of his road.

After all that, I'd still sure appreciate some opinions on any benefit to clearing out all the vegetation at the water's edge all around the pond. Cattails, LOTS of thick grass, willows, etc. I think I will have this done anyway, again, for aesthetic reasons if no other. I know all this vegetation provides little members of the food chain to be plentiful and available to the aquatic and other ecosystems, and it will doubtless grow back quickly. If anything seems insufficient for providing habitat for frogs, tadpoles, etc., I'll create some with a few pallets or something.

Thanks again!

I do think that a siphon drain at the other end, with the pond being further deepened at the new inlet, would get sediment/muck to slide towards the new drain. It may take time ( years?) but it probably is the best option for a regular maintenance feature. Perhaps with aeration stirring the water, it may work fast.

I am not sure about cleaning up those edges. They are steep, and more digging at the edge will probably get the ground to collapse into the water. You sure don't have the leeway to lose more ground there.

We used a long reach that was in the Montrose area last summer. It could reach 60' out. That would probably totally solve your problem in just a few hours. Maybe they will have that machine around again this summer. The guys name was Bill Gray and he did a great job for me.

Old Farm Pond Update

Hey Board,

I moved forward with some renovation of the old farm pond I mentioned above. The pond was drained, the dam was cleared of all trees, etc, and then a new clay core was put in and the dam was raised about three feet. The clay came from my property and was burnt red and of high quality. See pics and then I'll post my issues/concerns:
[img]http://i1382.photobucket.com/albums/ah241/mglanham1/IMG_1590_zps3xzs7vlz.jpg~original[/img]
[img]http://i1382.photobucket.com/albums/ah241/mglanham1/IMG_1028_zpsunoqgrju.jpg~original[/img]

[img]http://i1382.photobucket.com/albums/ah241/mglanham1/IMG_1594_zpsqmdo1790.jpg~original[/img]

In the three pics, one is of the early dam construction, one is how the dam looks today (pic with son), and the bubble picture is what I find behind the dam after heavy rains.

Behind the dam there are two very small natural springs. These springs run clear and cold. The contractor said he dug very deep in front of them to put the core in and never hit those springs. IE, the water is actually spring water and not a leak from the dam.

The pond essentially fills up right to the old water line and won't climb up the dam any further. My contractor thinks that we just need more water and that it should fill up in time. My concern is that there is a leak and the bubbles confirm this.

Anyone out there have springs that run underneath their pond? I'm curious if its possible that as the water level of my pond rises....it somehow finds its way under the dam/core and bubbles back up.

The property is located about an hour or so from me, so it's hard to monitor.

Any thoughts or opinions would be appreciated.

I'm not following how the bubbles confirm any leak...the bubbles kind of look like they are produced from decay gasses and soil settlement to me.

The contractor said he dug the core "deep", but did he dig down to and tie it into good clay? How was the core compacted? Was any of the rest of the pond clay lined and compacted?

A pond can be built over springs if a suitably thick, well compacted clay liner is created. If springs flow into your pond, they can also become drains as water seeks it's lowest level..

mglanham and others, please help!
I'm new to the forum, but have gotten a lot of great info lately. Thank you!

I have a newly acquired large pond that is need of a lot of work and looking for tips based on your relevant experience.

Problems and Current Condition: It is 4.4 acre pond. Silted in (unsure how much) such that water lillies are growing around entire perimeter covering about 2 to 2.5 acres (where the water is between 0 and 5 feet). There is coontail throughout. Pretty bad muskrat infestation (though 15 fewer as of this weekend). Deepest is 15ft in one small area. I'm told it is very old (>50 years). It does not have a drain pipe...just earthen spillway that has some washout problems. Back of dam has lots of trees. Water is crystal clear. Had cows in it for a few years, but they are all off it now.

Solutions that have been discussed/proposed (in no particular order):
1. Have the dam cut, dig it out with dozer, etc. Had a local excavator with lots of experience tell me this would be astronomically expensive because he said i would not believe how much muck/silt is in the bottom due to age.
2. Don't clean out, just cut a new core on the back of dam and raise dam about 6 feet. This would significantly increase size of lake. Not sure I want one that big...but the property would support it. Seems like burying the problem but not sure if that matters.
3. Siphon it down about 6 or 7 feet and then have the edges only cleaned up with dozer or excavator.
4. Perhaps a combination of 2 & 3. Clean out edges and then only raise water level 2-3 feet.
5. Chemical and Biological approach: Kill aquatic life with chemical and die. Install hefty aerations system and apply the bacteria.

All of the above solutions would be hired out to local professionals.

Objectives are Aesthetics and Fishing and maybe Swimming without spending an absolute fortune if possible.

Thanks in advance guys...

Welcome to PBF MidMoAdam!

I think there are lots of variables that come into play on a project like that. With the money that will be involved, regardless of the option chosen, I would invest in a pro pond builder for a consult. IMO, this is not a project you want to take the,"Let's try this" approach. I'm sure if you sent a PM (Private message) to Bob Lusk he could either help you himself or steer you to someone that can. There are several good books in the Pond Boss store that should also be helpful.

Good Luck!

Bill D.

Thank you. I appreciate the advice.

Adam

Big project.

Welcome to the forum.

The lillies can somewhat selectively be controled with a herbicide. I say somewhat selectively because the rhizomes of one plant may be connected to the one next to it. So a systemic herbicide could kill several down the chain if you are only trying to selectively kill off part of the lillies. If you want to kill them all not a problem.

Any herbicide control of weeds be careful to not do all the pond at once. Too much dead matter decaying all at once can cause a low DO event and fish kill. Kill off sections at a time over a period of time.

Coontail I know what is because it grows wild in local streams but I am unfamiliar with its control.

Muskrats can be trapped.

15 ft sounds like enough depth to me but I am much further south. Down here we usually do not dig ponds deeper than 10 feet. But your location may need to be deeper to prevent winter kill.

Your options sound thought out. None are likely cheap, but what is today? At least you have a nice size BOW to work with.

Thanks John,

I'm fine with the 15 foot depth. The problem is it is only in the middle....around the edge is so shallow. It can be 100' from the shoreline before it reaches 4 ft deep in some parts.

Adam

Yes that is problematic. Lots of shallow water just begs to be filled up with aquatic vegetation.

When it comes to cleaning out something of that age, it is often just as economical to just build an additional pond, leaving the original one "natural" and being what it already is. But if the current pond is in a perfect strategic location, cleaning out might be the only option.

In our area we could just take a trackhoe and go around the outside and deepen what we could reach and help it a lot. I have done that to one very old pond on my place. But not all areas can do that without breaching the sealing bottom layer and creating a leaky pond. You would have to seek local advice about your soils before doing something like that. We have mostly solid clay we dig into.

That is exactly the problem. The pond is perfectly situated because it is the view from the back of my house. I'm looking at it from my dinging room table as I type this. I could build another one but would barely be able to see it due to terrain, so that is not an option.

I'll look into the soils. I think we can excavate the edge no problem.

Do you seen any major drawbacks to the idea of raising the dam to raise the water level 6 feet or so? Assuming the construction is done properly. All of the sediment and nutrient would still be down there. Is that bad?

Thanks

Raising the level, if practical, is likely one of your best options. You don't get rid of the old nutrient load, which can be a negative, but it sure avoids a lot of the problems that come along with cleaning it out.

If you do raise the level, by all means, get dirt from around the outside edge and slope what will become the new banks just as you would in a new pond. This will prevent you from having the same problem ten gears down the road that you have now. If you can raise the new level enough to put all existing shallow water too deep for weeds to grow, and shape the new bank areas at 3 to 1 and deep enough, I think that could be a moderate cost solution to your problem. In the new outter bank area you could also do whatever you wanted with new fish structure before it filled. That is if you don't mind managing your already existing fish population.

Thank you. I appreciate that insight.

Assure that you mix the new soil with the existing stuff at the top of the dam. You don’t want a seam that will leak

One thing to think about as you are considering your new pond level is that it will not always be at full pool. I have ended up raising 5 of my ponds level by at least a few inches (nothing major like you will be doing).

When you are designing the new full pool level and envision the new banks and perhaps a dock or other features, a person tends to see it at full pool level. But with a watershed pond in the midwest reality is it will only be at actual full pool maybe 10 or 20% of the time. For short times it will be above full pool while water is exiting the overflow, but for a cconsiderable part of the year it will be an inch to perhaps a foot below full pool during dry periods.

So in your "vision" of what the new pond will look like after finished, consider also what it will look like at 6" below full pool. With adequately sloped sides it may not look much different. But with lots of shallow water almost flat banks it can look quite a bit different.

I went out today and walked the property to get a better idea of how much runoff is going to this pond and then measured that area with an online mapping tool. Turns out it is only ~25 acres of runoff including the pond itself. I was previously guessing it was almost double that.

Any estimate as to how much pond that can support?

I would describe is as a gentle to moderate slope. Mostly brush-hogged fescue pasture, some no-till row crop.

Thx

Hi MidMo,

The MU extension office suggests 10-20 ac runoff per surface ac.

https://extension2.missouri.edu/G9474#size

At times I wish I had a little more runoff for my 3 acre pond, then a couole times a year I wish I had less. My pond has minimal watershed area and in fact my NRCS guy designed and we installed a terrace in adjacent field just so we would have more runoff.

I can not remember off hand exactly how much area we have but I'm guessing it no more than 25 acres and maybe no more than 20.

Thing is, we get about 42" rainfall a year and it is not uncommon to get two or three inches in a single rain. So at certain times we get a lot of runoff.

If you have a good NRCS agent, they should be able to help you.

post with pictures of water going over emergency overflow