A newly stumbled term, which we quite like, is flood hunting, or the act of traveling to sites of inundation. What compel flood hunters are probably the same as what compels other disaster tourists: curiosity, adventure, the thrill of the sublime, Nielsen ratings points. But we like to think that they partake in such a dangerous pastime for their own edification as well, i.e., to witness hydrological and geological processes previously only experienced second-hand and to gauge how the built environment reacts in the face of total systemic failure. So besides the rare desert floods and the Mississippi spilling over its banks, one could add to the agenda Los Angeles' concretized river filling up, acqua alta, the formation of quake lakes and the creeping high waters behind the Three Gorges Dams.
We also like to think that flood hunting could be a subgenre of tactical tourism, a critical activity that looks at spatio-cultural conditions largely invisible or ignored during dry periods but pronounced during flood events, e.g., New Orleans' socioeconomic inequity spatially demarcated by Hurricane Katrina and levee failures.
However, if flood hunting is too much of a cardiovascular thrill, a more relaxing option might be the gutter dérive, or the act of tracing urban stormwater runoff on the surface, the positive of sewer spelunking. It may sound like a boring way to spend a rainy day when you could be dry indoors tweeting or updating your Facebook profile, but if your city is topographically blessed or if it's Portland with its green streets or if it's a city in which Marti Mas Riera has been let loose or if it's a city of experimental gutter-scapes, oh, the fun you will have!
How about bulwarking, the act of rambling through monumental flood protection infrastructure? Should be popular recreation in our future climate changed coastlines.
The Great Climate Change Park