What you see here is rainwater (“stormwater runoff”) flowing down the street gutter along the curb and into the bioswale. The collected stormwater is absorbed by the sandy soil on the top (engineered soil) and stone layer at the bottom, and seeps into the ground underneath in a process called “infiltration.” Water that is absorbed by the trees and plants or remains on the surface of the Bioswale is then released into the air as water vapor. Most of the curb runoff is being directed into the inlet, but during some rainstorms, water may go past the inlet and go straight to the catch basin. If the bioswale reaches capacity, the water will overflow at the outlet and go into the catch basin the way it normally would.
