What is the typical depth of a curtain drain relative to hardpan?

The typical depth of a curtain drain is usually around 2 feet relative to hardpan. This depth is significant because curtain drains are designed to intercept and redirect groundwater away from areas where water may accumulate, such as near foundations or into septic systems. Positioning the curtain drain at this depth ensures that it is effective in capturing excess moisture while remaining above the hardpan layer, which is often impermeable and can impede the natural flow of water. By being placed at this strategic depth, the curtain drain can effectively drain and prevent water from pooling, maintaining a stable environment in the surrounding area.