What must curtain drain bottoms be graded to provide?

The proper grading of curtain drain bottoms to provide positive drainage to the surface or a catchment basin is critical for the effective functioning of the drainage system. Positive drainage ensures that any water collected by the curtain drain is efficiently channeled away from the area, preventing water buildup and maintaining proper moisture levels in the surrounding soil. This is essential for preventing water-related issues, such as flooding or saturation that can compromise the integrity of septic systems.

Designing the curtain drain with a slope that directs water flow towards a catchment basin or the surface allows for the controlled management of groundwater, which can otherwise affect septic systems by causing them to back up or fail. Proper drainage design is part of effective land management and is particularly important in ensuring that wastewater treatment systems operate efficiently without interference from excess water.