I have a farm pond that is probably 60-80 years old and the steel overflow pipe in the deepest end was already corroding badly when I bought the land. I watched as the pond level got lower and lower due to water leaking thrugh the sides of the corroding pipe. No one I asked could give me any advice on correcting the problem without draining the pond and losing a tremendous quantity of fish (bass and bream). Then the pipe corroded at the very bottom and the entire pond drained anyway. I want to replace the overflow pipe but don't know how to go about this or what materials to use. It seems that PVC pipe would be best to avoid a recurrence of the same problem (corrosion), but I read somewhere that PVC pipe was not recommended due to risk of breakage. Also, can I run a slightly smaller diameter pipe through the existing portion of corroded pipe that runs horizontally through my dam or do I need to dig up the entire length of pipe (probably 30-40 feet in length at the base of my dam)? There is a spillway (not a pipe, just a shallow trench) at the upper corner of the pond which carried off water when the pond was at full capacity after heavy rains. Do I really need an overflow pipe at all? I have only seen water in the spillway two or three times in 10 years so it seems it would take Noah's flood to wash out my dam even if I plugged the old pipe with concrete and let the spillway deal with any overflow. Any suggestions?

Charlie,

your emergency spillway did not come into play because of the stand pipe drain. I would recommend that you either replace with a new stand pipe or install a new siphon system. I would not plug the old drain and let the emergency spillway handle all the water flow, it was not designed to be the primary drain and will probably erode over time.

If you replace the stand pipe drain do not sleeve it inside the old drain, I have seen this attemped and it does not work

Charlie,
Listen to the pro .. from experience I can testify he knows of what he speaks. I bought property where the stand pipe had collapsed & the emer. spillway came into play. All was ok for a couple of years then "Noah's flood" came & I all but lost my dam! Half of it was gone! Shawn always gives good advice.
Ric

Charlie ,The fact that you lost your lake is sad.This is some of the problems that I see alot and it is most of the time late.There is a few options to look at.Shan is right about the spillway it was not designed to hold the flow that it will have and substain for the next 60 years.However, there are ways to modify it to hold the flow.It is going to be expensive to try to replace the stand pipe that is already bad.I have done this many times and the easiest way that I have found to fix your problem is to close it off with concrete.Cover the opening with an end cap but don't stop there cover that with a heavy guage plastic at least 6' radius of the pipe.Then cover that with 4to6'of good clay .The fact that this dam is old tells me that it has eroded to some extent in places and should be repaired at this time sloped to 3to1 and packed in all across the front.Set your water level and modify the emergency spillway.Sometimes you can dig down to the desired water level and install your pipe in that spot or just add a liner to the mouth of the spillway and riprap it to keep the erosion down or place flat stones to give it a nice decorative look .These are some options and you can decide your best course of action.I hope it works out for you. DOC

Thanks for all the good advice, guys!