Terraforming Robots Proposed to Combat Urban Flooding

Parts of San Rafael, a city just north of San Francisco, are sinking about half an inch per year, which has resulted in neighborhoods like the Canal District sinking three feet. This situation places them at greater risk of flooding from rising sea levels, with cities globally facing similar threats.

Terranova, a startup, is proposing a novel approach to combat this issue by developing terraforming robots that inject a wood waste slurry into the ground to raise the land and mitigate flooding risks.

Laurence Allen, co-founder and CEO of Terranova, highlighted that traditional solutions like seawalls could cost upwards of $400 billion in the U.S., with individual city solutions ranging from $500 million to $900 million, which are often unaffordable for cities like San Rafael.

The startup estimates it can lift 240 acres of land by four feet for approximately $92 million, a fraction of the cost of seawalls. The injection process involves using tracked robotic units that autonomously drill wells and deliver the slurry to depths between 40 and 60 feet.

This method is designed to take advantage of inexpensive waste wood mixed with undisclosed materials to create the slurry. The company has developed software that utilizes geographic data and core samples to model subsurface conditions and inform the injection patterns through a genetic algorithm.

City planners and contractors can visualize the projects using a tool reminiscent of the game SimCity, allowing them to design and execute land-lifting plans efficiently. Safety measures include having human operators on-site during the robotic operations.

The process takes about two hours for the slurry to consolidate once injected. Although there are concerns about the potential for the wood slurry to exacerbate earthquake risks, Allen argues that the risks associated with seawalls and dikes are also significant.

Terranova, which recently raised $7 million in seed funding, aims to expand beyond urban flooding solutions to include projects for remediating wetlands facing similar threats from subsidence and sea-level rise.

The urgency of rising waters has led the company to prioritize urban projects like those in San Rafael, reflecting a personal commitment from Allen, who is a native of the city and passionate about its preservation.