When Hurricane Sandy submerged a chunk of lower Manhattan, our office was on Broadway, on the ridge at the center of the area. A little over a year ago, we moved to the corner of Broad and Stone Streets, in a lower area where a lot of neighboring buildings flooded to some extent. Various large-scale projects are in different stages of planning or construction to mitigate the effect of future storms, from making it easier to seal off subway ventilators, to building a scenic berm around the southern tip of the island.
Meanwhile, building owners in the area are looking for less-than-hideously-expensive ways to protect their buildings from catastrophic flooding should another Sandylike storm hit. A number of the newer big buildings have arcades at street level, the result of too-narrow sidewalks (this part of town has a 17th century Dutch village street plan) and zoning bonuses given to developers who created public amenities. Those two facts combined lead to those curious boxes in the picture above. That’s 85 Broad Street, across from our office, and the brown metal boxes on the sides of the arcade columns hide brackets where temporary flood partitions can be mounted. A storm like Sandy gives plenty of warning, so it’s realistic to say that the building staff will remove the covers, put the partitions in place, and wait for the water to come.
This may seem a little strange, but it’s worth noting that the entire historic center of Prague is protected from river flooding using a similar temporary-barrier system. In that case, the only permanently affixed equipment are a series of sockets in the pavement paralleling the river front. When there’s upstream flooding, the covers over the sockets are removed, posts set in the sockets, and barriers erected between the posts.