How one founder plans to save cities from flooding with terraforming robots

San Rafael, located just north of San Francisco, is experiencing significant land subsidence, sinking approximately half an inch annually. While this might seem minimal, it has resulted in certain neighborhoods, such as the Canal District, dropping three feet, significantly increasing their vulnerability to flooding due to rising sea levels. The situation is not unique to San Rafael; many cities worldwide face similar threats, with an estimated 300 million people at risk of regular flooding by 2050. The financial burden of constructing seawalls to combat this issue could exceed $400 billion in the United States alone. In response to this pressing challenge, a startup named Terranova is proposing an innovative solution: instead of building seawalls, why not elevate the land? The company is developing robots that will inject a mixture of wood waste into the ground, gradually raising the terrain to counteract historical subsidence and mitigate flood risks. Laurence Allen, co-founder and CEO of Terranova, highlighted the dire situation in the Canal District, stating, "The canal district is really far under sea level." He noted that the city's attempts to find solutions with flood consultants have yielded exorbitant estimates for seawall construction, ranging from $500 million to $900 million—an unattainable figure for a city with a population of around 60,000, many of whom live in poverty. Terranova claims it can safeguard San Rafael and similar cities at a fraction of the cost. For instance, the startup has estimated that it could raise 240 acres of San Rafael by four feet for just $92 million. Recently, the company secured $7 million in seed funding, led by Congruent Ventures and Outlander, with additional investments from GoAhead Ventures, Gothams, and Ponderosa, bringing its valuation to $25.1 million. The method of lifting land through underground injections isn't entirely new; however, Terranova argues that its approach offers significant cost savings. The primary material used—waste wood—is both affordable and readily accessible. This wood is combined with undisclosed materials to create a slurry that is pumped from a 20-foot shipping container using a robotic injection device. These tracked robots autonomously navigate the site, drilling wells to deliver the wood slurry to depths of 40 to 60 feet. Allen asserts that as long as the slurry remains moist underground, the wood will not decompose, allowing the company to generate carbon credits to help offset expenses. The entire operation is orchestrated through proprietary software developed by Terranova. By leveraging public geographic data alongside core samples collected during water well construction in California, the company has devised a subsurface model that directs injection patterns via a genetic algorithm. City planners, contractors, and other stakeholders can interact with a SimCity-like tool to visualize and finalize project designs, which in turn guide the robotic units on where and how much slurry to inject. Human operators will be present on-site as a safety measure. Once the injection process is complete, it takes approximately two hours for the slurry to solidify. Terranova has been testing both its robotic systems and the accompanying software at a pilot site for over a year. Although some experts have raised concerns about the potential for the consolidated wood slurry to amplify earthquake shocks, Allen maintains that the frequently cited alternatives also carry risks. "We believe our solution will mitigate earthquake issues compared to traditional dikes and seawalls," he stated. Terranova plans to generate revenue by partnering with contractors on various projects. The company aims to keep costs low enough to make its land-lifting approach appealing for a range of applications, including the restoration of wetlands threatened by subsidence and sea level rise. Nevertheless, amid the urgent threat posed by rising waters, the company's primary focus remains on urban areas. "I’m from San Rafael, born and raised," Allen expressed. "I really want to save the city."