The company that built a 1.7-mile long, one-lane, 35mph car tunnel underneath the Las Vegas convention center and called it transportation innovation is making new moves in Texas.

Elon Musk’s Boring Company has applied to build a private tunnel beneath Tesla’s Gigafactory in Austin. The building application, first identified in a report from Electrek, was filed with the city of Austin on Tuesday.

The new document is short on details, but states that, “the applicant is proposing private access tunnel along with associated improvements.” The project is named “Colorado River Connector Tunnel,” and the address given for location is 12733 Tesla Rd (zip code: 78725), which is on the north end of the Giga complex. Based on the application, the proposed tunnel would be about two miles long.

As a bonus, the filing identifies the project site as being located within 100 feet of a 100-year floodplain. The Gigafactory is bordered by the Colorado River and its wetlands. Given Musk’s impeccable understanding of how underground tunnels are impacted by surface weather conditions, it seems like nothing could go wrong here. Exhibit A, this tweet:

Except, of course, subways flood all the time. And it doesn’t need to be a 100-year flood. My Brooklyn stop gets dicey after a few hours of heavy rain.

Musk moved Boring’s headquarters to Pflugerville, Texas (just north of Austin) in 2020. Since then, the company has filed development permits for test sites in the state, but this proposed tunnel is the first plan that’s progressed to a building permit application, according to Electrek.

It’s unclear from the application what the exact intent of the Texas tunnel might be. It could be a pilot site for some mysterious new technology, an underground lair, a pedestrian walkway, or—most likely—another Boring car tunnel (dubbed simply “loop”), meant to shuttle Musk and his minions across the factory campus.

So far, the only operational loop is the one underneath the Vegas convention center, but the company has big plans to expand in Nevada and has also been eyeing sites in multiple other locations.

Just last week, Boring received approval to make its big Las Vegas loop plans even bigger. The company announced the proposed system of tunnels would be more than 34 miles, as opposed to the original 29.