Water and sewage

The water and sewage info view. Water Pumping Stations are highlighted blue (at left edge), sewage treatment plants are highlighted in green, and the area of effect of the pipes is shown in light blue.

Citizens and city services need fresh water and a way to get rid of sewage to stay healthy and function properly.

The water network and the area covered by the piping (shaded in light blue) can be seen in the water info view. This info view will also colour-code buildings by whether they have adequate water supply or not, highlighting gaps in the city's network. It is possible to have multiple, unconnected water networks, each with their own pumps and outlets. However this is rarely an optimal strategy on the majority of maps.

If the water or sewage service is insufficient for demand, buildings furthest in the network from the supply will be the first to lose service. Buildings will only tolerate an inadequate water and/or sewage supply for a short time before becoming abandoned. Unlike most other service buildings, water and sewage buildings do not employ any citizens, with the exception of the inland sewage treatment plants.

Water network

Supply

There are two types of water supply buildings: water towers and water pumping stations. Build these facilities to provide fresh water to your city. Water pumping stations must be built next to a water source, such as a river. It is a a good idea to take note of the water's direction of travel. You want to place your pumping station upstream of any sewage drains so that it will not be contaminated by water pollution. Water towers may be built anywhere on land, but you must ensure there is no ground pollution near the water tower or your water supply will be contaminated and citizens will become sick. These water producers must be connected to your city by water pipes.

Distribution

Once a water supply building is erected, water pipes must be placed to transport water to your city and back to the sewage outlets. Water pipes must be continuous and connect directly to the supply and drainage buildings, but otherwise buildings only need to be within an 11-cell radius of functioning pipes in order to be supplied.

Water Pipes are constructable from the start of the game, and are built underground in linear stretches. They cost ₡20 per cell to build and ₡0.08/week to maintain. Networks of pipes need to be continuous in order to function. Water pipes do not get in the way of other underground constructions (i.e. road/metro/railway tunnels). User-placed pipelines deal with both freshwater and sewage, there is no need to plan separate networks. Water pipes can be severed by natural disasters such as earthquakes and meteors.

Sewage disposal

See also: Pollution#Water pollution

Not only do your citizens need water, but they also need a way to deal with sewage. Drain pipes and water treatment plants must be placed on a shoreline and be connected to the water supply network. Drain pipes simply dump raw sewage into the water and can quickly cause massive amounts of water pollution. Water treatment plants process the sewage before dumping the water and can eliminate most of the pollution. The "eco" versions from "Green Cities" operate in the same fashion, but with reduced pollution output. It is a good idea to place sewage plants downstream of the water supply buildings to prevent accidental contamination of the water supply.

Inland Water Treatment Plants do not require a body of water to empty into. They process the sewage and dump it underground, causing some ground pollution, so do not place them near Water Towers. These can be used in any city, but may be a necessity where there is little or no bodies of water available on a map.

Water storage

The Tank Reservoir building allows for excess water to be stored for later use. When placed, the tanks are empty and have to fill up with water. If the demand for water is higher than the production, the tanks’ water supply will automatically start to be released. Once the tanks are empty, no more water is released. The tanks will start to fill again once the production is higher than the demand. This is especially useful if a disaster destroys some water pumps and/or towers and causes the water production to drop below the demand.

Service Buildings

Building	Unlocked	Cost (₡)	Upkeep (₡/week)	Pollution	Noise Pollution	Water (m3/week)	Electricity (kW)	Size (cells)	DLC	Notes
Water Pumping Station	Start	2,500	240	0	25	0	240	3×5	-	Pumping capacity: 120,000 m3/week Doesn't require road access. Do not place in polluted water or water supply will be contaminated.
Water Tower	Start	3,500	240	0	25	0	240	2×2	-	Pumping capacity: 60,000 m3/week Doesn't require road access. Do not place on polluted ground or water supply will be contaminated.
Large Water Tower	Big City	9,000	720	0	25	0	320	3×3		Capacity: 160,000 m3/week Doesn't require road access. Do not place on polluted ground or water supply will be contaminated.
Tank Reservoir	Boom Town	25,000	720	0	0	0	480	5×12		Water tanks fill when there is excess production, and release water if production is low. Storage capacity: 600,000 m3 Operating Rate: 120,000 m3/week
Fresh Water Outlet	Tiny Town	2,500	320	0	10	0	240	1×3		Drain capacity: 24,000 m3/week Doesn't require road access.
Water Drain Pipe	Start	2,500	320	0	10	0	240	2×7	-	Drain capacity: 120,000 m3/week Doesn't require road access.
Eco Water Outlet	Start	4,000	480	0	10	0	480	2×7		Drain capacity: 60,000 m3/week Pollution output reduced. Doesn't require road access.
Water Treatment Plant	Big City	15,000	640	0	15	0	480	8×9	-	Drain capacity: 160,000 m3/week Pollution output reduced by 85% Doesn't require road access.
Eco Water Treatment Plant	Capital City	25,000	560	0	15	0	1,280	8×9		Drain capacity: 160,000 m3/week Pollution output reduced by 94%. Doesn't require road access.
Inland Water Treatment Plant	Start	2,500	320	100	10	0	240	5×7		Drain capacity: 120,000 m3/week Causes ground pollution. Does not require a body of water to empty into.
Eco Inland Water Treatment Plant	Start	4,000	480	45	10	0	480	5×7		Drain capacity: 60,000 m3/week Causes ground pollution. Does not require a body of water to empty into.
Advanced Inland Water Treatment Plant	Big City	15,000	640	20	15	0	480	10×9		Drain capacity: 160,000 m3/week Causes ground pollution. Does not require a body of water to empty into.
Eco Advanced Inland Water Treatment Plant	Capital City	25,000	560	7	15	0	1,280	10×9		Drain capacity: 160,000 m3/week Causes ground pollution. Does not require a body of water to empty into.
Pumping Service	Busy Town	100,000	1,600	0	40	0	1,440	8×14		Vacuum trucks suck up flood water, and empty at Pumping Service. Released through sewer system. Storage capacity: 1,000,000 m3 Vehicle Capacity: 10

School of Engineering

Building a School of Engineering Unique Faculty building within a Trade School Campus Area will result in reduced city water consumption and sewage.

Heating systems

Heating was introduced to Cities: Skylines with the release of the Snowfall DLC. The citizens of a city will use heating to counteract the effects of the cold weather. The default approach is to increase the use of Electricity during a cold snap, however if municipal heating is available then it will be used instead. The heating system is integrated within the water system and pipes can be upgraded and downgraded between the two.

Heating Pipes are constructable from the Boom Town milestone onwards, and are built underground in linear stretches. They cost ₡100 per cell to build and ₡0.20/week to maintain. Networks of pipes need to be continuous in order to function. As with water pipes, heating pipes do not get in the way of other underground constructions (tunnels, metros etc.).

Service Buildings

Building	Unlocked	Cost (₡)	Upkeep (₡/week)	Pollution	Noise Pollution	Water (m3/week)	Electricity (kW)	Size (cells)	DLC	Notes
Geothermal heating plant	Boom Town	55,000	480	0	75	160	160	9×15		Heating Output: 80 MW (0.6/tile, 6₡/MW)
Boiler station	Boom Town	60,000	640	35	75	80	320	6×4		Heating Output: 120 MW (5.3/tile, 5.3₡/MW)