The firefighters are not without water because of a drought or missing reservoirs. Local water tanks - the things you see along the road or on hills, get filled up over time throughout the day to create pressure in local pipes and handle spikes in demand. When demand exceeds local tank design capacity, pressure drops or water stops flowing. The higher you go in elevation, the bigger the pressure problem. All of the tanks were full at the start of the fire and were refilled multiple times during the day.
explained by city chief utility engineer:
“Those tanks help with the pressure on the fire hydrants in the hills in the Palisades, and because we were pushing so much water in our trunk line, and so much water was being used. ... we were not able to fill the tanks fast enough,” she said. “So the consumption of water was faster than we can provide water in a trunk line.”