Cities: Skylines: How to Avoid Pollution

In the consistently popular game Cities: Skylines, a lot of buildings produce pollution. Pollution can stain the land and water brown, and it kills off the trees and grass in the area. It also reduces property values and can make people sick if they have to live in polluted areas or drink polluted water.

That's why one aspect of Cities: Skylines is managing pollution levels. It's impossible to completely avoid pollution without using DLC buildings or special mods, but the right policies and the right building choices can keep pollution to a minimum and keep citizens happy and healthy.

Switch to Non-Polluting Industries

Cities Skylines Forestry District — A forestry district in Cities: Skylines.

When players reach the Worthy Village milestone, they unlock the ability to create districts and assign them specialized industries. Two of these industries, farming and forestry, don't cause pollution (at least within the game). By switching all industrial areas to one of these two specialties, players can keep up with demand for industry zoning without sacrificing the environment. However, several farming and forest buildings in the Industries DLC do produce pollution.

Another option is to allow regular industrial buildings to upgrade. Upgraded industry buildings tend to produce less pollution than the level one versions.

Of course, the most important thing players can do with industrial zones is place them far away from residential zones. Even farming and forest zones produce noise pollution which can annoy and sicken citizens.

Place Sewage and Water Treatment Plants Downstream

Cities Skylines Water Treatment — Two water treatment plants in Cities: Skylines.

Most maps in Cities: Skylines have lakes and rivers players can pump for water. Those that don't can use water towers instead. If one of these water pumps draws from polluted ground or water, then citizens in every part of the city will start to get sick.

Still, waste water has to go somewhere, and the safest way to get rid of it is to dump it into a river with a water drain pipe. These pipes pollute the river based on how much sewage the city is producing, and while water treatment plants reduce this pollution they don't get rid of it completely (at least without mods or DLC buildings). That's why both types of sewage output should go downstream from the city's water pumping stations. Players can identify water direction by selecting a pumping station or drain pipe and zooming in close to a river. The water surface has arrows that point downstream, and their size indicates how fast the water is moving.

Focus on Green Energy

Cities Skylines Offshore Windmills — A collection of offshore windmills in Cities: Skylines.

Coal and oil power plants generate a lot of power, but they also generate a lot of pollution. Green energy sources like windmills and solar power plants are more expensive per megawatt, but they're much better for the environment and keep pollution to a minimum. As an added benefit, green energy doesn't need imported resources and so these power sources won't add to road congestion.

However, green energy sources still produce noise pollution, which is also bad for residential neighborhoods. This means players should still keep these power sources well away from housing areas. Of course, the fact that windmills can go anywhere on the map makes this very easy.

Keep Noise Pollution in Mind

Cities Skylines Highway Sound Barrier — A highway with a sound barrier in Cities: Skylines.

One last form of pollution players have to worry about is noise pollution. Noise pollution isn't nearly as dangerous as regular pollution, but it can still harm residential neighborhoods if players let it build up too much.

There are several ways to keep noise pollution in residential zones to a minimum.

Use road decorations and highway sound barriers to keep street noise down.
Stick with narrow roads in neighborhoods and never build residential zones along central routes.
Keep in mind that low-density commercial zones create a little noise pollution, high-density commercial and industrial zones create a lot of noise pollution, and office zones and residential zones create no noise pollution.

Noise pollution is even more inevitable than regular pollution, but players only need to keep it away from residential zones to keep their citizens happy.