Originally Posted by STL Ponds and Waterfalls
I'm missing something with the no drain aspect. There is a lot of runoff going into this pond with 2 downspouts feeding it as well. I look at the drain as cheap insurance.
If it will give you peace of mind, then, by all means, install an sub-liner drain.
All we are saying is that you likely don't need it. Surface run-off does not equate to hydrostatic pressure. In fact, the higher the velocity of run-off, the less likely there will be any hydrostatic pressure. The force exerted by the weight of the water in the pond will prevent any water being forced under the liner by any surface run-off that would be expected on a hillside.