A new solution for flood-prone cities? Concrete made from shellfish waste.

This time of year, bushels of rhubarb, potatoes, and lettuce can be harvested in abundance at The People’s Pantry, a community garden that doubles as a fresh food pantry in Blackpool, England. There, residents living in adjacent affordable housing units tend to the fresh crops they grow and then eat. And lining the ground beneath each raised bed of soil is a smooth sheet of concrete, dotted with slivers of ivory shells. 

“They’re not so obvious at first … but as you walk on it, the shells become more apparent as you go...