Pond Boss Forums INTRO Questions & Observations My Pond Project Start to Finish

I agree with what was said. The sand vein has to be cut off at both ends, the ends packed properly with clay, and teh sand vein plated over with clay (I'd go 24" thick) to ensure that water won't reach the sand vein and leak out of the pond. If you don't dig it out and refill it with good clay, or cut the ends and plate over the top, how do you know that there IS a bottom to the sand vein?

If you have enough clay, the whole pond bottom and sides up to the high water level should be packed with clay in four, 6" to 8" lifts and compacted with a sheepsfoot roller or multi-tired pan scraper full of dirt. Just facing the dam with a liner and hoping it'll hold won't work. What's to prevent the water from going around the liner, or going thru the liner if it is punctured?

There is no one-way valve in sand. If the water pressure is higher in the pond than the water pressure in the sand seam, then the water will run out of the pond.

Trust me, it's MUCH cheaper to fix it right now, when there isn't water in the pond than later when you are full of water and fish. There is no way to fix it after the fact unless you drain it and get to the point where you are at right now.