Which layer is not included in the construction of permeable pavement?

The choice of compactable subgrade soil as not being included in the construction of permeable pavement is accurate because permeable pavement systems are specifically designed to allow water to infiltrate through their surfaces, minimizing runoff and enhancing groundwater recharge.

In permeable pavement construction, the typical layers include an open-graded bedding course, which supports the pavers and allows for water infiltration while ensuring stability in the pavement structure. The open-graded base reservoir layer also plays a crucial role, as it collects and temporarily stores the water that passes through the pavement, facilitating drainage and promoting natural filtration.

Concrete pavers form the surface layer of permeable pavement and are often interlocked to create spaces for water to flow through. In contrast, the subgrade soil beneath a compactable layer is typically not compacted to deter water retention. The focus in permeable pavement systems is on creating a series of interconnected voids that allow for drainage, rather than relying on a compacted subgrade layer that could impede this flow. Understanding the roles of these various layers highlights the unique function of permeable pavement in stormwater management systems.