On a hot day, the tap and the air conditioner work as a team: one pours water, the other gulps electricity. A city is like an organism, with water and power as two connected vessels. In the past, they were studied separately, but now scientists have gathered data from six US cities over ten years and built a model that predicts both resources at once.
It turns out the main signal is El Niño, the warm current in the Pacific Ocean. When it strengthens, cities get hotter and drier. People water, wash, and cool off more, so water and electricity are consumed together. The model showed that water is even more sensitive to weather than electricity.
Now utilities can monitor El Niño and prepare in advance for surges in demand. In this way, a city, like a single organism, learns to breathe in rhythm with the climate.
In Chicago and Cleveland, no seasonality was found in water consumption, unlike in the other cities. This may be because both cities are located on the shores of the Great Lakes, which smooths out climatic fluctuations.