Pond Boss Forums POND CONSTRUCTION Renovating a Pond or Lake? Weak section around old drain pipe

Hello again,

Where do I start – how about describing the situation?

Bought a property with a house that dates back to 1820something which is nicely restored. Close to the house is a pond of app. 1.5 to 2 acres.
The pond is built on a slope with a horse-shoe shaped dam. The shallow side is towards the house and the fish and other aquatic life is breeding there every year. The far away side is the deeper side and app 8 to 9 feet deep.
The pond is fed from a creek that runs by its side and has a natural overflow back into the creek. Water is typically cristal clear. Tons of bass of various sizes, blue gill, 3 snap turtels, blue herrons the occasional eagle fishing etcpp – all in all a well balanced and well established habitat.
So far so good. As far as the research goes the dam has been built in the late 1950s or early 1960s and never saw any maintenance. The forest behind the dam crept onto it and there are plenty of decade old tress scattered all over the dam from all sides. The deepest section of the dam had been equipped with a drain pipe which goes under the dam and that (as far as corrosion of the valve and the tip of the pipe on the dry side of the dam tells) never had been used.
According to Murphy a cluster of the five largest tres on the dam is more or less on top of the expected routing of the pipe as is a muskrat hole from the water side (no more muskrats thanks to a 22cal scoped helper). I do not wonder that that area of the dam seems to be weakened.
When I purchased the property in 2004 there was already a wet spot in the vicinity of the drainpipe and around the end of the pipe a dripping occurred. However, during the dry period this year (we had 8 weeks without rain this summer in eastern PA) the creek water level lowered and so did the water level in the pond. As every year when need arises I started a sump pump in the creek with a capacity of app. 30 gpm. To my astonishment the pond water level did not rise as usual but barely kept level with all the water being pumped in. An inspection of the known little leak showed that by now the wet spot expanded to app. 6 feet by 15 feet and the dripping is now a steady flow. Best guess is a leak of app. 20 to 24,000 gallon a day around that old drainpipe. The water coming out there is clear without sediment, so I hope/guess that the dam is not actually washing itself out.
Of course the dam section with the pipe is on the far side of the dam, deep down in the woods with absolutely no access other than hiking. The woods in that area are undisturbed for app. 65 years and look accordingly.
I searched the internet and the local sources of information and came up with the one named company. They sent someone for a site inspection and came up with a 40+ pages report listing the area’s ground condition based on the information from the Army corps of engineers who maintain two large dams in the area, showing that the creek feeding the pond is listed a valuable / preserved water (or however the state called it) and an impressive amount of information that do not really help the situation.
However, they had three suggestions:
a) Bring in small equipment from the side of the house across the crest of the dam to drill a pattern of holes around the estimated path of the drainpipe and pressure fill the holes with Bentonite/clay. They do not give this a 100% chance of solving the problem but will not need to lower the pond water level or bring in heavy equipment. The pricing was unacceptable high in the 40K. I would say they do not want to do this and I do not want to throw that kind of money onto something that is not 100% secure to succeed.
b) Mobilizing heavy equipment and cutting a pathway through the woods to reach the weakened dam section. Cutting away all large trees in the weak section (best guess app. 30 to 50 feet of the length of the dam). Test digging to get the exact direction of the drain pipe to be able to localize it on the other side of the dam under water. Syphoning the water level down and installing a separation wall with diesel pumps around the water side end of the pipe. Diggin out half the dam at the water side and removing the inner half of the pipe. Refilling and compacting the dam with Bentonite/clay. Then digging out the outer half of the dam in that section, removing the outer half of the pipe, refilling and compacting as before. Removing the temporary walls/dam and pumps to allow the water level to come up again and getting the heavy equipment out of the woods / demobilizing. Total expected duration beteen 2 and 4 weeks depending on weather conditions and problems coming up. Pricing is 45K
c) Same as b) but only working on the outer half of the dam, digging out a part of the drainpipe and refilling around that pipe to install a solid Bentonite/Clay plug. Pricing is 37K

In parallel (while having them on site anyway) I want them to take install a nice creekbed-style water inlet from the creek. Actaully there is a 55 y.o. underground clay pipe that is frost damaged, bent due to ground movement and every year I need to dig aout a ton of silt that dettled around the pipe inlet on the creek-side. I envision them to dig out the pipe (they will need to remove sections of a horse fence and at least one tree) dig a trench, line it with some rubber mat and nice river rocks and remount the fence. Pricing 6.5K

Personally I do not appreciate the version c) since it is curing the symptom and not solving the root cause.
While the water level is down I could work on some ground stabilization and cleaning up on the shallow area, too……if someone could guide me to the donkey that is supposedly pooping gold.

Anyways – I would like to get all sorts of input from the experts here since I have never done or witnessed anything like that.
Does the scope of work sound acceptable or is there eventually an easier solution?
Does the pricing sound reasonable or is it based on that company being the only one around here doing stuff like that?
What do I need to do to support the survival of the fish during the period of lowered water level?
Is it a reasonable promise from their side regarding the partial pond draining while I think the pipe is the lowest point of the pond and they will end up draining it completely?
What do I have to be aware of before committing to any contract?
In short – what could go wrong or what could I do wrong?

Thank you for your patient reading and thank you for any advise, hint or piece of information. IF anybody knows another company in the area north of Allentown or more general north of Philadelphia / east of NYC that does projects like the described one – I would appreciate any contact since I am used to work with three independent opinions on project that expensive.

Frank

PS: IF someone explains to me how I could add photos I will gladly put some in.

Wow GermanPA, sounds like you got a big project ahead of you. As I was reading your very descriptive and thought out post, I kept saying to myself that photos are going to be helpfull for everyone to get a view of your situation. Then at the bottom I see your comment of photos.

Link to posting photos; link

Look at Bill Cody last post at that link. Simple and easy, at least it was for me. You need a photobucket account, but that is easy too.

As far as the rest, the pros are going to have to help you out. The price seems high, but it could be your obstacles around the pond. That is where photos are nice. Seems like for all that work, the whole dam might be reworked because of all the trees. You might fix this one problem, and a few years down the road a dying tree will force you thru another session of the same..... Lets wait and see what others say, and work on those photos. Welcome to pondboss.

Have you had time to try pics again?

My apologies - but no.
By now i changed my job site from PA to MO and the drive was a long and tiring one.
Also - before I left Pa I got the washed out driveway fixed, got a backhoe, dug a trench for the drainpipe...etcetc

No whining I was overbusy.
I am trying to get the photos up as we speak.

Again - sorry for the delay,

Frank

http://s1273.photobucket.com/albums/y417/germanpa/

does that work?

If yes:
Three aerial.
One around 1959, balck/white - house but no pond
http://i1273.photobucket.com/albums/y417/germanpa/19048-1951_zps2f3d003c.png

One around 1961, black/white - house with pond and dam is clean and clear of trees
http://i1273.photobucket.com/albums/y417/germanpa/19049-1970_zpsbc6672fb.png

One today, color. I added the app. position of the drain pipe in blue and the yellow snake is the approach they will need to cut through the "jungle" for the shovel and trucks. No other access possible.
The dam is totally overgown with trees as can be seen in comparison with the 1961 aerial. http://i1273.photobucket.com/albums/y417/germanpa/Presentation1_zpsb5cb697b.jpg

then there are three more photos taken from the second floor balcony across the pond.
http://i1273.photobucket.com/albums/y417/germanpa/33Balkon1_zps62fd7807.jpg
http://i1273.photobucket.com/albums/y417/germanpa/34Balkon2_zps17e26673.jpg
http://i1273.photobucket.com/albums/y417/germanpa/35Balkon3_zps2978effb.jpg

I could not find any photos of the leak itself - these photos must be on the external harddrive in PA...me being in MO actually.

Frank

You got it!!!!!!! Looks like a beautifull place you have there. I can see why you want to keep it from deterioating. I think alot of the cost they are giving you is due to the difficult access. You may have to deal with the whole dam in the future because of all the trees on it. If you could do a "fix-up" on the drain in a price range that wouldn't be too costly, and then prepare for a major overhaul in the years to come. Trees on the dam are a problem, but you could get by for alot of years before they become a drastic issue, or it could be next year. From what I have seen on this forum, once a pipe leaks, it just keeps getting worse till you lose the pond. You have to fix at least that so you don't lose it all.

I vaguelly remember in a past post somewhere about failing drain pipes. They were talking about sealing the entire pipe with some kind of material that that was pumped down and expanded,(like a plastic/concrete?). Might try a search for that, or somebody else may know of that? If that was sealed of, then you could put a new siphon drain system without cutting thru the core of the dam. Just a thought, I'm just a newbe at this.

Anybody else have ideas?

There is a back issue of the PB magazine with an article that Mike Otto wrote dealing with drains.

Thank you very much for the answers so far.

Let me raise a different question;
Assuming that the suggested method of digging out the old drainpipe and than rebuilding that dam section is feasible / the right way to do it I am just stumbling about the price.

Usually I would like to ask someone for a second opinion or proposal but I cannot find nobody (I seem to be either too stupid to google proper or to use the available research tools proper - or there is no expert for dam repair/rebuilding in the area).
Does anyone have a contact for any company or person with experience in dams / repair in eastern PA, NY-State, NJ, Delaware or adjacent states?

Frank

I put a call in to a friend,now he is just a dirt mover as far as I know with a VERY good reputation in my town.I don't know his pond work or experience and I'm waiting to hear back from him.

With that said chances are he'd be willing to give a estimate and while i don't know his level of experience regarding pond work.I have no doubts he'd be willing to work with someone who does.......in other words move the dirt as per a expert etc.

I'm overseas at the moment but he is located in S NJ.If you want PM me and if he is up too it I'll forward all information,

Contact the NRCS. They generally keep a list of dozer operators. A word of caution is that they may or may not have pond experience. Inclusion on the list is voluntary on their part. Pond repair experience is much different than pond building or other types of dozer experience.