My first contractor did not core deep enough and my pond leaked.My new contractor went further down and hit limestone.The rock had cracks with sand in between and some big crevices. We had to dig this layer out to the hard solid rock below. We dug up a layer of sea shells 6" to 8" thick and a layer of porous rough green sand between the limestone and solid blue rock. Here are a few pics but they don't do it justice.
The limestone started coming up in elevation and we continued till we got above the water line. My pond looks like a limestone quarry. We had to clear off about two loads of pine trees to get more clay to finish the core. I'm going to use the biggest rocks for structure and the small limestone for slopes on the sides. Most will crush under the bull dozier tracts.
He busted the limestone with the teeth on the trackhoe.Most busted fairly easy but some of it was tough. I do have some exposed rock in the very bottom with some springs.The springs don't seem to have much pressure and the water level stays the same. Never gaining or losing.This is a small area(20x20) slightly lower than my drain. Do you think it would be a good idea to cover these up with clay and seal this area?
Springs giveth and springs taketh away....Cover them under a good 3 foot thick layer of exceptionally well compacted clay! The exposed rocks will most likely leak also...especially limestone!
Exposed rock in the pond is not always bad. It depends on the type of rock, if it's a smooth rock without cracks and joints you should be fine. On the other hand if the rock is cracked and ruff looking then I would say cover it with clay and compact it with a COMPACTOR!
