In coastal regions all over the world, the issue of rising sea levels and coastal erosion is becoming more pressing each day. Due to their low altitude and the high numbers of people living there, river deltas are particularly vulnerable to these side effects of climate change.
The CALTROPe Project – the brainchild of the Hungarian design collective S39 Hybrid Design – uses mangrove saplings to help encourage the natural production of protective dams. Mangroves are a natural barrier for flood waters, acting as a sort of “buffer” for incoming waves. And they help stabilise coastlines too, by trapping sediment and stopping them from being washed away.
CALTROPe is the name they’ve given to a set of modular units – hollow, lace-like structures – that can be installed parallel to the shore in coastal areas. Mangrove saplings are then planted inside them.

This modular system acts as a sort of set of intricate plant pots, that can be stacked on top of each other to form a platform just under the surface of the water. The saplings can send their roots all the way down to the ground through the hollows of the structures.
The lace-like structures are able to catch the sediment that the river transports, which will then slowly build up to form a natural dam, effectively creating new coastline.
The structures are made from a mixture of concrete and organic substances, and are designed to degrade and disappear after 40 years, by which time the mangrove trees are hopefully strong enough to stand on their own. And the dam is left too of course, formed by the captured sediment, that protects the land beyond from rising water levels.
It’s a simple but effective project, and minimally-invasive too. According to theie official Facebook site, a pilot project is already in the pipeline.
This is a translation by Marisa Pettit of an original article which first appeared on RESET’s German-language site.