How much pea gravel is recommended to surround the perforations of a subsoil drain?

The recommended amount of pea gravel to surround the perforations of a subsoil drain is typically 12 inches. This greater depth of gravel is essential as it helps facilitate adequate drainage and provides a larger volume for water to flow freely. Additionally, a 12-inch layer of gravel creates a stable structure that supports the drainage system and prevents soil from clogging the perforations of the pipe. Proper drainage is crucial in preventing water accumulation in the surrounding soil, which could lead to issues such as flooding or erosion.

When designing a subsoil drainage system, ensuring that the gravel layer is sufficient in height also allows for improved filtration of water through the gravel, protecting the drainage pipes and ensuring efficient operation over time.