|The mound of dirt shown on the right side of the sidewalk blocked stormwater flow|
Prior to the bioswale project, the median lying between the San Marco Library's sidewalk and Lasalle Street blocked all stormwater flowing from the library's roof and lawn and funneled the runoff to a low area adjacent the main pedestrian crossing in front of the library.
As you can see, the elevation of the dirt creates a berm of approximately right inches tall in some places, blocking water flow.
However the new design will have an elevation profile lower than the elevation of the sidewalk's edge, allowing runoff to enter the swale for attenuation and treatment.
Bioswale and rain garden science is based upon biomimicry - imitating nature's successes.
Excavation is imminent and plants are scheduled for delivery soon.