May 8, 2025
Crews completed a project milestone in late April, placing the final concrete lift on the inlet/outlet tower. The final lift brought the total amount of concrete in the tower to 903 cubic yards.
“Tower construction went smoothly overall,” said Project Engineer Becky Brush.
Excavation for the 50-foot-tall inlet/outlet tower began in September 2024 and concrete placement for the foundation followed in late October, rendering the total timeline just under nine months. The entire tower will be under water when the reservoir is full.
Now that concrete placement is complete, crews will wrap up final items once the structure “settles” into the earth. Due to the tower’s weight, engineers expect the tower will consolidate a small amount, and they want to let that initial movement occur before making any connections to the tower. These include connecting the pipelines from the tower to the tunnel and encasing them in concrete, then installing the eight trash racks and testing the bulkhead placement. Brush said she expects dry testing to begin in late-May.
The bulkhead is a large steel plate that, when in use, blocks reservoir water from entering the pipe so personnel can complete maintenance on the tunnel. A crew that includes divers will conduct bulkhead testing both before the reservoir starts to fill and after the tower is at least 20 feet underwater. Right now, wet testing is planned for August 2025.
After the initial dry and wet testing of all tower components, it will be 10 years before the next scheduled testing occurs.