In October, engineers on the RiverRenew team visited our scale-model drop shaft that demonstrates how water will enter the proposed tunnel system. This model will allow our engineers to test a variety of conditions and configurations to optimize a design best suited for Alexandria. The model was constructed and tested by our partners at the University of Iowa – Hydroscience & Engineering C. Maxwell Stanley Hydraulics Laboratory (IIHR), a world-renowned center for research focusing on hydraulic engineering and fluid mechanics.
Diversion facilities will direct millions of gallons of combined sewage into the new tunnel system for conveyance to AlexRenew's water resource recovery facility.
In the below video, you can see water flowing into the drop shaft and tunnel. The drop shaft dissipates the energy of the falling water and removes air before it enters the tunnel.
The model in the video simulates a drop shaft with an inside diameter of 40 feet, but the plexiglass model is about one-tenth that size.