Standing in the construction site formerly known as Waterloo Park, you can get a sense for the enormity of a project to tunnel underneath downtown. It’s the northern entrance to the Waller Creek Tunnel, which is designed to prevent the usually slow-moving stream from flooding in a storm. When complete, it will be 30 feet round – nearly big enough to fit two trains.

Gary Jackson, the city’s public works project manager, says that the Waller Creek Tunnel is nearly identical to what would be built for a subway tunnel. In fact, Austin’s foundation rock is the perfect material for digging. The Austin Chalk, as it’s called, is a native limestone that cuts easily underground but is strong enough to support buildings above.

The Waller Creek project is digging up an old question: Why not a subway for Austin? Continue Reading →