How one founder plans to save cities from floods using reclamation robots

Parts of San Rafael, a city north of San Francisco, are sinking about half an inch per year. That may not seem like a lot, but in total it means that some neighborhoods — like the Canal District adjacent to the bay — have sunk by three feet, making them more at risk of flooding due to sea level rise.

San Rafael is not alone. Cities around the world are threatened by rising sea levels, with 300 million people at risk of routine flooding by 2050. The cost of building seawalls to keep out the water could exceed $400 billion in the United States alone.

A new startup is proposing an alternative: upgrading the city instead.

Terranova is building robots that will inject wood waste into the ground, slowly raising the ground to eliminate historic subsidence, and hopefully prevent those parts of the city from flooding.

“The canal area is well below sea level,” Lawrence Allen, co-founder and CEO of Terranova, told TechCrunch. He added that the city is working with flood consultants to find a solution.

“The answer, every answer every time, was anywhere from $500 million to $900 million worth of seawalls, which if you’re from San Rafael, you know they can’t even afford that. There’s about 60,000 people and a large portion — which is surprising for a city in Marin — live in poverty.”

Terranova says it can protect San Rafael and other cities like it for a fraction of the cost. In the case of San Rafael, the startup committed $92 million to raise 240 acres by four feet.

The company recently raised $7 million in a seed round led by Congruent Ventures and Outlander with participation from GoAhead Ventures, Gothams, and Ponderosa, TechCrunch has learned exclusively. The oversubscribed round values ​​the company at $25.1 million.

Raising the ground by injecting stuff underground is nothing new. Terranova’s idea is that it has developed some new methods that make it cheaper.

The first is the material: wood waste is inexpensive and easy to obtain. The startup mixes it with other undisclosed materials to turn it into a slurry. The result is pumped from a 20-foot shipping container into the second cost-saving item: an automated injection device. The tracked robotic units move autonomously around the job site, drilling wells through which wood mortar is delivered to depths of approximately 40 to 60 feet.

As long as the mortar stays wet underground, the wood shouldn’t decompose and the company can sell carbon credits to offset costs, Allen said.

All this is managed by software developed by Terranova. The company uses general geographic information as well as data from wells drilled throughout California, which are mostly captured during water well construction. In doing so, it created a subsurface model that informs injection patterns, which are determined by a genetic algorithm.

On the back end, city planners, contractors and other stakeholders can use a SimCity-like tool to sculpt the virtual landscape.

When the plans are completed, they direct the auto-injectors, telling them where and how much to inject. Human operators remain on site as a safety precaution, Allen said. Once the robots are done injecting, it takes about two hours for the slurry to consolidate, he added.

Terranova has been testing robots and software at a pilot site for more than a year, he said.

Although some experts have questioned whether embedded wood mortar will worsen earthquake shocks, Allen said the frequently mentioned alternatives also carry risks. “We think it will help [with earthquakes] Opposite dams and sea walls.”

The company plans to make money by splitting project revenues with contractors. It hopes costs will be low enough that the process will be attractive to a range of land-raising projects outside cities, including treating wetlands that are disappearing due to either subsidence or sea level rise.

But given the urgent need for rising water levels, cities are Terranova’s first priority. “I’m from San Rafael, born and raised,” Allen said. “I really want to save the city.”