What should be done with the bottom of a dry swale before adding soil media?

Roughening or scarifying the bottom of a dry swale creates a better interface between the underlying materials and the soil media that will be added later. This process enhances the soil's ability to absorb water and improves the establishment of vegetation, which is key for effective stormwater management. By creating a textured surface, it facilitates the infiltration of rainwater and minimizes the risk of erosion.

Properly preparing the base of a dry swale is essential for ensuring that the swale operates efficiently. This roughened texture promotes the rooting of plants, which helps stabilize the soil and enhance filtration. The other options do not promote this level of integration or functionality. Leaving the bottom untouched does not provide the needed texture for soil media adhesion, while filling it with gravel could prevent the soil media from properly interacting with the swale's infrastructure. Compaction would lead to reduced porosity and infiltration rates, counteracting the goals of a dry swale designed for stormwater management.