Pond Boss Forums POND CONSTRUCTION Building a dam Cleaning out silted pond

I am starting a project to clean out a silted 2 acre pond. I do not know it's age as I just purchased the property. The pond is feed by run off from about 30 acres and has a spring that flows enought to keep it from freezing in 15 degree weather. The pond has a 24" metal standpipe that creats a pool in the pond that is 5' below the spillway. The top of the dam is 5' above the spillway.
I recieved a bid from a contractor and his plan was to trench through dam spillway to drain it. I have been reading about the syphon system from Pond Dam Piping. The dam is very stable and established and I am concerned about trenching to drain it. Would the syphon be a solution to drain the pond? What are the pros and cons?

Ifishnow, what are you going to do with the mud that you dig out and how is it going to be moved? I have cleaned out some ponds where I cut a trench in the dam wide enough for a big LGP dozer to go through. Then I could push the mud right out the back, pretty quick and easy. Dealing with mud is expensive, figure out a good plan for the mud before anything is started. I have never had any trouble with filling in the trench afterward and making it hold. Siphoning works great if you do not need to cut the dam.

Nick Jones
www.soilmovers.com

I will be very interested in what you do with your pond. I live in SE Pennsylvania and have almost the exact same situation as you: recently purchased land with a 2 acre pond, spring fed, 1-1/2 to 2 feet of muck, water level 2-3 feet below original level, old drain pipe. I talked with 1 contractor who charged by the hour. He wanted to cut the dam to drain it and then push the muck out of it through the cut dam. He didn't want to put a number on it but said it could cost me up to $100,000 to do the job!!

RobA - that figure of $100,000 seems to be way over the top!!! I had 1 acre cleared(good # of trees) and a 1 acre pond dug(10'-4'). This cost me $13,000. I am new to "pond livin" but was very satisfied with my price. Definitely shop around!!!

My contractor quoted $3000 to do it last year but he never got "_Around to it-". I plan on taking the mud out with a Kubota tractor if I can get it to dry out some. I have a dump truck and plan on taking the mud to a ravine that we are trying to fill. I have also considered renting a Track Hoe. Sounds like the contractor's bid was low? Are there any fans of siphon? It seems like a good idea for future draining and maintenance. My idea is to keep the stand pipe and install a siphon with valves to turn it off.

Ifishnow,

Welcome to PondBoss! Your situation is one that has been discussed on this board in the past. A search on the topic should yield some helpful suggestions.

Here are some thoughts. You didn't mention how much silt or bottom pudding you are trying to deal with and why. If your goal is to increase the depth of the pond, and the pond has a dam, the easiest and most cost effect way to achieve this is to increase the height of the dam. Moving dirt is more costly than adding to the dam. Hopefully the dirt contractors here will corrrect me if that statement is incorrect.

If you have a limited amount of muck, an aeration system may be one approach to deal with the situation. On the other hand if removing the silt is your only option, have a gameplan in place to deal with the spoils. Some members here have used the material to build islands in their ponds which helps keep costs down. Others have used the material to fill in low areas of their property. It was amazing to me to see how much material was excavated from my two little ponds (.25 ac and .10 ac).

Lastly, if it were me and I had the option, I'd try to avoid breaching the dam, especially if its structurally sound and doing what it was built to do.

Good luck,

Russ

Russ, Thanks for your reply; the top of my dam is about 10' above the water level. So by adding some material to the spillway and increasing the stand pipe could get more depth. Are there any siphon users out there? Does the siphon flow continuously?

Lots of discussions on siphon systems. Here's some threads:
http://www.pondboss.com/ubb/ultimatebb.php?ubb=get_topic;f=20;t=000387

http://www.pondboss.com/ubb/ultimatebb.php?ubb=get_topic;f=20;t=001150

http://www.pondboss.com/ubb/ultimatebb.php?ubb=get_topic;f=11;t=000007

http://www.pondboss.com/ubb/ultimatebb.php?ubb=get_topic;f=1;t=000086

You can do a search, but search of all catagories would be wise as people have posted topics everwhere.

Ric Thanks. I am travelling to Ohio next month and plan to install a Siphon to draw down the pond I also have a gas powered 12,000 pump to help. Once I play in the mud I will post the out come. I feel very forunate to have found this site and I ordered the magazine.

By the way I spend 30 years in the military so thanks for reconition. Keep those young warriors in your prayers.

Ifishnow,
Be sure and inspect the riser pipe and outlet pipe.
30 years is the about the life of corrugated metal pipe, depending on the alkalinity of the soil. The pipe will typically deteriate on the bottom, more towards the pond side. The sides of the pipe will look ok. The riser will rust out down a foot or 2 from the top. z

Thanks Z. I need to inspect and find out the age of the pipe. If it is rusted out what are my options? I think the pipe is bout 40' long and goes through the center of the dam. I want to avoid digging out the Dam if possible. This is my first pond and I appreciate the advise. Looks like quite a job before my three grandsons can start catching bluegills.

Ifishnow,
If the existing pipe and/or riser is rusted out the most usual option is digging both out and replacing with a pvc pipe.
Plugging off the existing pipe and installing a siphon system might also be an option. (haven't tried that).
Digging through the dam and rebuilding it is pretty safe.
I do not like the idea of cutting a drain in the spillway. Spillways are placed on virgin soil when designed, never fill. If a flood happened, where the fill was at in the spillway could erode a lot. Water shouldn't go over the top of the dam so fill in the dam is safer from erosion from water. z

Ifishnow,

In a similar situation last summer, I trenched, with my backhoe, through the spillway. After draining most water, then cleaned out what I could and pushed the remaining muck in to form a submerged island in the middle of the pond. Then, raised the dam, or at least tried to raise the dam until I got caught by fall rains. Will finish the dam this spring. Raising the dam is much cheaper than excavating....and the island provides great structure. Also, I would consider just going with natural spillways and forget the costly pipe.

Ifishnow, my experience with dump trucks hauling mud is money. You will have to keep the mud cleaned up so the dump truck can work, maybe requiring a dozer. The mud will want to stick in the bed of the truck so you will probably have to dig it out with something like a backhoe pretty often. Weight wise you can only haul about half as much mud compared to dry dirt. Mud=$.

Nick Jones
www.soilmovers.com

Ifishnow,

Welcome to the confusing and wonderful world of pond ownership.

I think you need to ask a serious question on how deep your pond really needs to be. I have a pond that is 60 plus years old that started at 14 foot and is now about 8 feet deep. I do not plan to desilt it until it gets to less than 4 ft. and I don't expect to live that long.

My point is: A shallow pond is more than adequate for fish and in a deep pond, most fish will live in the top 3 ft where the oxygen is. The depth of a pond should only serve you and the specific type desired fish.

You may want to spend the money on aereation, restocking, fish habitat, wildlife habitat, piers, picnic areas, etc., etc.

Beware of possible having a fish kill in non-aereated deep ponds. A deep pond will turn over and kill the fish if the oxygen in the deep part is depleted and the top of the pond gets colder than the bottom (due to weather changes).

Good luck sifting through all the good advice posted on these subjects.

I thank everyone for their input. I leave Florida for Ohio in about two weeks. I am looking for 8ft pond and I really do not know how deep my pond now. I will let all know what the out come is.

I just returned from Ohio and have made some decisions about the pond. I found out it is only 14 years old and is not silted. It only is 4 feet deep and was built collect run off from a strip mine operation. I am going to raise the water level about 5 feet by using 12 inch plastic clavert pipe inside the exsisting 24 inch stand pipe. Top of the dam is 9 feet above the current water level. My only concern is one of the springs feeding pond has a rust that sticks to the plants and rocks where it flows in. Do I need to deal with it? How?

Ifishnow,

Not to steer you away from any of the good advice above or your goals, but you also may need to keep in mind ceratin things when it comes to dredging (and new ponds as far as that goes)the needs to satify our governemnt (like local, county, and state gov. as well as Depart of natural resources). Meaning - some states you need a re-dredge permit even if its only 1/4 acre. And if it's in a wetland area (and it does't have to be on your property) that may require bringing in the US Corp of Engineers. And if so you may have to haul out the dredged spoils instead of just spreading out on your other part of the land.

Just my 2 cents.

Woody

Update.!! The pond is full 8ft 1/2. I drained the pond by cutting a slot in the overflow pipe. The pond dryed except for a stream from the two springs and run off. I hired a backhoe contractor for $1600 to clean out the 10" of silt and redress the dam. Checked with county watershed authority and I did not need a permit. I cemented in a new plastic drain 15" pipe as the stand pipe and closed a 4 inch drain pipe that I used to keep the waterflowing while we worked on the stand pipe and dam. Total Cost $2100. Tomorrow I go to buy fish. I am having the water tested but it is full of frogs aready.

Thanks for the advise and the magazine is great.

Yahoo...congrats, Ifishnow! Pics...we need pics! (before and after, if you don't mind)

I have cleaned out several ponds by trenching to draw down the water and then used a large excavator sitting on the dike, like a Cat 225 to dig a sump inside the pond. A small dozer, like a Cat D3 then can push the muck to the sum where the ecavator will lift it out and depoist it on the rear side of the dike. This should cost $2-$3k for a one acre pond. Using a large excavator it takes only 8 hours for an acre pond where the muck was 2'-6' deep.