Sherman Dam

Sherman Dam is the largest dam in the Western hemisphere. Its hydroelectric power plant has a capacity of one million, seven hundred fifty thousand kilowatts.

Said power plant has ceilings and platforms built perfectly for robots the size of cars. How convenient!

Canon History
Shortly after the Decepticon arrival on Earth, Megatron led his troops to Sherman Dam in an attempt to gather energy. He easily captured the facility from its human operators and sent Rumble to create more energy for the dam's generators by using his pile drivers to make a tidal wave. The other Decepticons then made energon cubes from the energy before the waves began to tear the dam apart. As the water from the "tidal wave" overtopped the dam, the Autobots scrambled about evacuating townspeople downstream and creating diversionary channels to reduce the flooding. Optimus Prime and the rest of the Autobots attempted to stop the Decepticons from escaping with their energy haul, but were defeated. The Decepticons fled, though the weakened dam never burst.