Officials from Fort Lauderdale, Florida formally accepted a proposal from Elon Musk’s Boring Company on Tuesday to build an underground transit tunnel.
“This could be a truly innovative way to reduce traffic congestion,” Mayor Dean Trantalis said in a tweet.
I hope everyone there has a submarine to use in this new tunnel because it looks like it is going to be underwater before long. Elon’s tunnel projects haven’t exactly gone well in the past—just look at accounts from test rides of the Boring Company’s Los Angeles “hyperloop.” But building one in Fort Lauderdale comes with a whole other set of issues.
Like all of South Florida, Fort Lauderdale faces an extreme threat from sea level rise. The ocean there has risen by up to eight inches (20.3 centimeters) since 1950. Most Fort Lauderdale residents live less than five feet (1.5 meters) above sea level, including a majority in areas deemed Special Flood Hazard Areas by the Federal Emergency Management Agency. Things could get much worse, though. A conservative estimate forecasts up to two feet (0.6 meters) of sea level rise could hit Fort Lauderdale by mid-century, which would vastly increase the risk of flooding.
“Ft. Lauderdale is already dealing with regular flooding which is only expected to become more common and more severe given the effects of climate change,” Samantha Montano, an assistant professor in emergency management at Massachusetts Maritime Academy, said in a Twitter direct message.
What would a flood look like in the Boring Company underground transit system? Not great. Building underground in coastal locations has always been a risk. Non-Boring Company tunnels dug by cities like New York and Houston have flooded when storms have hit.
To make matters worse, Fort Lauderdale is built on reclaimed land made of limestone, sand, and marl—all highly permeable and porous materials. As the oceans encroach on the area due to storm surge or high tide floods, that geological base can easily get filled up. This may have contributed to the tragic collapse of a condo building in the town of Surfside last month, though we still don’t know for sure. (It certainly poses a risk to existing infrastructure long-term, let alone new subterranean infrastructure.) The geology is also why homes in South Florida are almost never built with basements; crews would encounter flooding if they dug too far down.
For infrastructure built underground, we already know how is faring due to sea level rise; the city’s sewer system requires $1.4 billion in repairs, and sea level rise is making matters worse by corroding pipes. A Miami Herald story published last year notes the city itself found 15 pump stations and 220 manholes could be inundated by 2050. How exactly does the Boring Company plan to get around these known issues? It hasn’t released a plan, so we don’t know.
Florida cities are taking steps to adapt their infrastructure to the climate crisis, building pumping systems to send water back into the bay and raising roads so that people can still drive when there are floods. But building the Boring Company tunnel would be a step in the opposite direction. If the mayor really wants to address congestion, building raised bike lanes or elevated public transit would offer more benefits than an underground tunnel full of Teslas driving at slow speeds.
“Part of proactive climate action is ensuring that every single new infrastructure project accounts for climate risk, and hazard risk more generally,” said Montano. “Building this kind of underground infrastructure in a community that is already facing persistent flooding seems like a poor use of resources.”