Pond Boss Forums POND CONSTRUCTION Selecting a site New Pond Question

I am not a pond construction person just one that has observed for 40 yrs new ponds that fill with water.

RAH has a good point. IF the springs are below the surface, once water reaches a certain level/height and exerts pressure on in-flowing deeper springs the water pressure can be strong enough to let/push water out instead of in.

When there is a well built and well sealed clay basin pond liner and it is pumped full, it stays full to the overflow pipe for weeks until evaporation starts to reduce the level. They often say that a new pond needs to fill and the water needs to soak up and into the soil to a point the clay fines are pulled into the bottom to reduce seepage. I think this concept primarily applies to pond build in a ravine with a dam. IMO sealed is sealed and I am always suspect when a pond fills and does not stay full or has a problem maintaining water to the overflow especially if rainfall is regular.

IMO your pond is showing seepage into the banks at this depth. To me this indicates inadequate compaction of the last 15"-18" of the sides because it was holding water below this depth. I think water has found a lateral seepage pathway out of your pond at is current depth. Water could be seeping out between layers of soil (lifts) or through some less than optimum clay that lined an area/s of the upper embankments. A common pond construction problem is the contractor gets in a hurry to finish and does not compact the last layers as well as earlier building OR the soil did not contain quite as much good clay as that in the deeper pond walls.