Rainfall, Waterfall, Rockfall

After a big rainstorm…

Kristina: I heard that 250 mm fell in 24 hours making it the worst storm in 250 years.
Alain: Hmm. Coincidence that the rainfall of 250 mm equalled the time since an equivalent big storm of 250 years. 
Kristina: Yeah. Odd that. Especially since there were no measurements being taken that long ago. Anyway, the rain was heavy. Walls fell in the street.
Alain: You mean your 10 meter retaining wall?
Kristina: Nope, a meter-high wall up the street. Still, a hundred houses in town are flagged as unliveable.
Alain: And five hundred houses still to be inspected.
_________

Voice-over
Rogue rainfalls may contribute to hill property prices falling, but flooded properties on the flat may depress prices even further. Freak weather events can slow a rising real estate market.