Given the size of the new bridge and the amount of rain that can collect on it, a water control swale (channel) was constructed in between the approach structures on the east side of the Bridge Project. This swale serves to direct large volumes of stormwater run-off, especially after heavy rain events, such as last night and early this morning. During those types of downpours, there will be a build up of water in this swale.
The swale runs from near Pico Avenue toward the east tower and drains into a very large Austin sand vault for treatment. The stones in the waterway also blunt the water run-off that is carried down from the bridge deck’s drainage system, keeping it from eroding the ground beneath them.
In the photo below, there is a little stone swale from the first approach column on the left down to the main swale. Each of the columns has a stone ring around the base and a similar mini-swale. The flat surfaces of the bridge’s columns are so large that the rain striking them alone would cause significant ground erosion at the base without these mini-swales, which direct the water into the larger swale.
This type of swale does not exist on the west side of the Bridge Project because the approach structures are so close to each other, and there is no large gap between them.
