What is a core trench?
The core trench is the most crucial component of the pond as far as its ability to hold water. In a majority of the soils in Northwest Ohio, there are three major layers of soil called horizons. The A horizon is the vegetation and topsoil layer, the B horizon consists of sandy clay, and the C horizon consists of primarily hard brown and gray clay. The A & B soils will not hold water as well as the C soils. In other words, water will soak through the A & B soils faster than the C soils. The core trench is basically an over-excavation of the A & B soils around the perimeter of the pond. This over excavation is replaced by the C soils which in turn seals the pond.
