120 Feet Below the Surface, Dallas' Most Important — and Most Spectacular — Project Begins

Twenty-six-foot-tall sound barrier surround the construction site between White Rock Creek and the Stonewood Terrace Apartments on Scyene Road, near Dixon Avenue. An armed guard secures the entrance. You would never know from the outside that behind those walls, and deep beneath our feet, lies the starting line of one of the most expensive projects in this city's recent history.This project, the Mill Creek Drainage Relief Tunnel, is also one of Dallas' most important projects. And, easily, its most breathtaking.By the time the clock strikes 2023, City Hall will have spent more than $300 million in bond dollars to protect billions of dollars' worth of properties — some of them the city's most expensive, most essential. The tunnel will run for five miles. It will be 35 feet in diameter. It is being dug 120 feet below this city's surface.Its project managers said over and over Thursday it's the largest tunnel being dug in this country at this moment.The Mill Creek project has also given us a rare glimpse at Dallas' prehistory, in the wall, 40 feet tall and wide, of millions-year-old rock serving as the as the project's starting line. This wall — what the contractors call the tunnel's "face" — reveals fractures that geologists believe were created hundreds of thousands of years ago.  Continue reading...