Ports and coastal cities already have to pour concrete. ECOncrete charges a premium to make that concrete useful to oysters, fish and engineers - then argues the habitat can pay for itself in permits, durability and avoided mitigation costs.

Terranova is pitching a counterintuitive answer to coastal flooding: instead of walling the water out, raise the ground up. Its $92 million quote to lift an entire low-lying district four feet above the floodplain undercuts the $500-900 million price tag of a conventional concrete seawall by roughly an order of magnitude. This story breaks down the math behind that claim, tests it against the only city that ever actually did it at scale — Galveston, Texas, which jacked up 2,146 buildings after the 1900 hurricane for the inflation-adjusted equivalent of about $94 million — and weighs the hidden costs, disruption, and engineering risk that a sticker price alone never shows.