Valentine's day coming up: the water footprint of cut flowers

Each rose has a water footprint of ~10 liters (see Mekonnen et al., 2012). 215 million roses are sold in the US, every 14 Feb, that's 2.15 billion liters (for numbers:

Mekonnen, M.M., Hoekstra, A.Y. and Becht, R. (2012) Mitigating the water footprint of export cut flowers from the Lake Naivasha Basin, Kenya, Water Resources Management, 26: 3725-3742.