City 16 is one of the many former Combine-controlled cities.
The Combine ran the city (like their other numbered cities) from the Seven Hour War until their downfall after the Uprising against them. The Resistance Government took control of the city and installed a new leadership. Who became running administrator of the city is unknown.
After the destruction of City 17 nine years after the Combine's downfall, the company the Evo Corporation moved their operations to City 16. They received controversy over their (not yet proven) ties to the dissolved cult/organisation the Clandestine Company, although it didn't hinder them from expanding their company. The Evo Corporation's new CEO G-Woman held a press conference dismissing people's claims about their corruption.