HELP..I need a real Sherlock Holmes here. I woke up Good Friday morning to a 1/4 acre pond basically run dry, about 3 feet of water at very bottom. This was a simple construction, simple center overflow pipe, connected to 40 foot run off pipe leading to micro pond. My son Went out in canoe, no visible cracks that we can see. I wiggled the center overflow pipe back and forth, and the water flow seemed to decrease. NOOOOO idea why or what caused this. The fellow that built the pond back in 1999 said he installed an emergency release cap, but I don’t know where that might be. Question 1. What happened? 2. If the damage is lower why did the pond stop draining? 3. Where could the emergency cap be?
Too little information to give you any definitive answers.
However, all of that water went somewhere!
If it has not rained recently, then you should probably go examine every single low spot surrounding the pond, and especially below the dam. Look for any wet spots or soggy soil.
If the water did not go through your banks, then it probably went through your pipe. Some failures are sudden. If a bunch of water suddenly rushed through your outlet pipe would there be any evidence in the waterway beyond the exit of the outlet pipe? I would probably check that area.
Do you have any muskrats or beavers at your pond? Beaver damage is usually easy to spot on your trees surrounding the pond. Muskrat activity is usually a little harder to spot. Either varmint can excavate burrows into your dam or the other banks. If they burrowed most of the way through, then the hydrostatic pressure of the water in your pond, may have pushed through the rest of the way and caused a leak.
What is the material for your outlet pipe? Galvanized might be starting to corrode after 26 years and allowed a leak. Are you at enough elevation in Middlebrook to get heavy ice on your pond last winter? Ice pressure can certainly weaken a pipe that is already corroding or loosen a joint.
If none of my suggestions seem valid, then it is probably time to closely examine your outlet pipe. I would put on a decent diving mask and examine the pipe by either swimming or wading. If you can't see well enough, then gently feel around the pipe and see if you feel a cracked joint or some small leaks.
DO NOT SHAKE THE OUTLET PIPE WHILE IN THE WATER. If the pipe breaks at the lowest point, then three feet of water pressure is definitely enough to pin your hand or arm in the hole.
P.S. I have no idea what an "emergency release cap" might be. Usually water going over the dam is the worst possible scenario for a pond, since it may result in a section of the dam washing out and draining the entire pond. One common cause of that is a clogged outlet pipe during a big rain event. Perhaps he installed a threaded cap somewhere along the horizontal run of your outlet pipe that he could screw out in an emergency? If so, then his "wrench extension" to the cap may have rotted away long ago. You might also examine the horizontal run of your outlet pipe if you do end up going in the water.
Good luck on finding and fixing your leak! I was just trying to throw out some ideas that may help you solve the problems since you are the guy with actual eyeballs on the scene.
I would assume the emergency release cap would be at the base of your vertical stand pipe, as in a tee with the center tee being extended up for elevation control one side of the tee going thru the dam for water exit and the other side pointing in to the pond itself and just capped, removing that cap would drain your pond but I have no idea how one would remove that cap in case of an emergency.
I would venture to guess tho, your problem is right at that tee area. You should be able to check the back side of the dam and see if the water actually exited thru the pipe or thru the earthen dam at some other place, that's a lot of water to be gone out of a pond and it will leave plenty of evidence as to the path it took.
Good Luck!
All the really good ideas I've ever had came to me while I was milking a cow.
Thanks gehajake and Fishing rod….yes what we can deduce is that is was a catastrophic failure at the T joint, all the water came 100% through the run off pipe. Right now it’s actually filling back up, but that’s only due to fact the a site of T break it’s clogged up with silt and vegetation. My only thought is to cut center stand pipe back few inches at a time , drain, then cut some more till this all drains out then make repairs.