Tunnel could bore through landowners’ rights

If you’re a fan of the local news (or perhaps Elon Musk’s Twitter account), you probably heard about the Alamo Regional Mobility Authority’s recent decision to enter negotiations with one of Musk’s companies, the Boring Co., to create a tunnel system between downtown and the airport to shuttle people in driverless Teslas.

This proposal has received mixed reviews — some praising its originality and its potential to sustainably reduce traffic, and others criticizing it as unresponsive to San Antonio’s true needs. The conversation about this project has ignored how a tunnel is likely to interfere with private property rights of the landowners between downtown and the airport.

In Texas, landowners have the right to develop the property below their surface as well as the airspace above their land. Hardly trivial, these subsurface development rights can be some of the most precious and important for landowners when they consider developing a site.

Construction often requires digging below a property’s surface to install essential foundation structures, utilities or drainage facilities that local agencies are required to build in flood-prone areas. If a landowner were denied the right to build below the surface or, worse, forced to remove preexisting improvements, that could substantially reduce the value of their land or make its current use illegal.

Crucially for San Antonio landowners, these are the exact rights the tunnel threatens.

Musk’s company proposes to install its project 30 feet below the surface, with a proposed width somewhere between 30 and 50 feet. This would mean landowners would be legally prohibited from constructing or interfering with a roughly 700-square-foot area underneath their homes or businesses. That would be a tall task for many — especially the larger commercial properties that are likely to be affected by this project.

Projects like this also may pose many latent problems. For instance, it is common for insurance premiums to increase for properties that host public infrastructure programs on account of the additional risk they bring. And largescale construction projects like this can change drainage patterns in a given area, making it more prone to flooding.

Some may not be worried about these potential impacts on their land because they would never sell their subsurface rights. However, it is likely that the Regional Mobility Authority would use eminent domain to construct the project.

This means it could condemn the subsurface rights needed for construction, even if a landowner is unwilling to sell and regardless of the ways that the project might interfere with existing building improvements or a property’s future development. The only thing the property owner is owed in return is “just compensation” for the land rights taken.

But determining “just compensation” in a given scenario can be confusing and often requires large expenditures on expert appraisers and attorneys. It is the poorest among us who are unlikely to be able to afford the services needed to make sure this right is fully protected.

Considering these pitfalls, we may want to reconsider whether the benefits of the tunnel are worth the serious and permanent problems it may produce for local landowners.