Cities Skylines: Critical services Cities: Skylines Guide
Last update: 04 May 2020
Electricity
Every building in the game will require electricity to work. If energy shortage doesn't last long, nothing bad will happen, but if it takes more than dozen days, citizens will move out and the manufacture will simply fall.
At first energy can be produced from wind and coal. Coal plant is cheaper than five wind turbines, which are needed for producing the same amount of electricity.
Later in the game you should invest in advanced wind turbines. They are placed on water and they produce 20 MW of energy, which makes them very economical. And they don't pollute air.
Other possibilities for very large cities are solar power and hydro power plants, which, fun fact, produces more energy if level difference before and after the dam is higher and can generate even 300-400 MW.
Water and sewage
Water in the game is provided by Water pumping stations and Water Towers. Their efficiency is pretty good, but you will need more than dozen of them for a large city.
They must be connected with rest of the city by pipes that provide water for 8 fields from the pipe.
Pipes drain sewage as well, the amount is equal to how much water they provide. Sewage should be removed, it can be done with drain pipes, that take the sewage directly to moving waters.
Later in the game you should replace drain pipes with water pumping stations that are 25% more efficient and remove 85% of pollution from sewage.
Garbage disposal
This service is mandatory the very moment it becomes available.
Landfills are very important part of city infrastructure, though they have one weakness - after some time they become full and are no longer able to collect any more garbage, and garbage itself won't decompose in there by their own.
Because of that, you should quickly reach new milestones to quickly unlock incinerator plants. They collect garbage and transform it into electricity, each maximum into 12 MW. Sadly, pollution around them is extremely high so you shouldn't build them near clean residential districts.
Garbage generates the greater unhappiness. Workshops might even go bankrupt because of them.