Written by: Vladimir Mijatović
Cities: Skylines

In the previous article about Cities: Skylines, I mentioned terraforming tools and left water creating and manipulation for this article. Even if this tool has only 2 options, it is far more complicated than any other in map creating. It also requires you to be patient because even if you can speed up the game simulation, it takes time for water to settle. You will still have to know how terraforming tools work, so if you haven’t read the previous article, head on over here and make sure you do because I will be continuing on that. Also, after you have read it, bear in mind it’s “as short as possible” explanation but if you want to know more, head over to this extensive and well-written guide from no other than MrMiyagi – Making Maps with Mr Miyagi – Guide, Tips and Resources. If you are not familiar with his name, he is famous for a large number of quality maps in the Steam workshop for Cities: Skylines, so his guide is a perfect reference.

Seas, Lakes and Large Water Surfaces in Cities: Skylines

Water can sometimes be very fickle and it takes time to see the impact on your map. Depending on your terrain configuration and water sources, you can create big lakes, small rivers, and fantastic waterfalls. Considering what you can gain from this tool, it outweighs the learning curve and when I saw the fantastic waterfalls that some users have made, it made me want to learn more.

The first thing I will cover is large water surfaces like seas and lakes. This is not valid for ponds or any other water surfaces separated from outside water. It is also important to know that all water manipulation takes time, and even if you can speed up the game’s simulation (which is highly recommended), you need to be patient.

Cities: SkylinesTo begin with, I need to mention that the game’s default plain level is 60. This means that when you start a new map, you will be given flat land whose altitude will be 60m (try using level tool to check this value). If you dig below this level and connect the hole to the map border, water will start pouring in without the need of creating a water source. At this point, it’s a good idea to pause the game, define the water surface, unpause and fast forward – in that order. The reason for this is that it takes a long time for water to settle down, and every change you make will take time as simulation needs to unfold. Each time you take away from the water surface, a huge wave will appear on the ground where you took it and will travel some distance across the map. That’s why it’s a good idea to define the basin where water will be, fine-tune the coast and then go with traffic (the best advice is to leave traffic for last). Don’t worry about waves hitting your infrastructure. They will obstruct the traffic for a short time, but will eventually dry out. This can have a much bigger effect if you claimed a large part of the water surface in the city that you’re already building. Even though you can shape the land after you started a city, this is one of the reasons to do most of the work in map creation mode.

You can basically make oceans and seas using only terraforming tools and then later adjust the sea level at any time. To do that, select the “Move sea level” tool and hover over your sea. As you click and drag to adjust the sea level, you will notice a line that goes up and down across any hills you have made. This line marks how high water will reach so be careful when releasing that left click. If this line is too high, you raised the sea level too much and begun a new flood (Noah is probably the only one who wouldn’t mind). As you cannot build underwater, be reasonable with this setting. After this, speed up the game and let the water settle. If you are not satisfied with the sea level, select “Reset sea level” and you’re fine. If it’s not working, check the value for sea level and adjust accordingly – you can even type in the values. After your “accidental” flood, you may notice that the color of the ground changed. This is because it was underwater and it will turn back to its normal color soon.

Sea tool is a pretty easy one, but I wanted to explain some water mechanics that will have an application with water sources as well.

Local Water Placing in the game

Cities: SkylinesWater mechanics are the same whether you are placing a sea or a small pond. Placing a water source is pretty simple: click on the tool and place it on a map. However, many people don’t know that they can regulate the height of the water level with water source. Before you place a water source, pause the game! This will give you time to play with the settings. Place a water source and hover over it: you will see two types of arrows – one horizontal and the other vertical. With the horizontal arrows, you can move the water source around and with the vertical, you can regulate the height of the water the same as you did with the sea level. For both, left click and drag until you are satisfied with the result – right-click will delete it. This is very useful in creating closed water sources that are not connected to the sea level such as ponds, lakes, and rivers. And as I said, after you place a water source, speed up the simulation and wait until the water settles down. It will probably overflow a bit and flood the surrounding area, but it won’t make any significant damage other than a brief traffic obstruction. A word of advice: if you want to make a small water source, like a pond, it’s much better for it to have its own water source than connect it to a river or sea. Even if the lake or pond is connected to another water source, put a dedicated water source as it will be far easier to control the water levels and current.

About how to Create that perfect River

This is where it gets complicated in Cities: Skylines. Another important thing to know is that water sources are not just spewing water, but they can also act as siphons. Take water sources as regulators for local water level, amount and current. This is very useful for controlling the flows of rivers. If you see a part of your river that is overflowing or has a dry river bed, this means you will have to put another water source to control the amount of water you have at that point. Many players have complained about this. To get one thing straight: water mechanics will act close to the one in real life, but expecting your river to behave like a real one by having only one water source is not how this game works. Even if your river bed has a perfect slope and height difference, having only one water source is not enough. I don’t want to get into water calculations too much, but to achieve a realistic water flow, you need to strategically place your water sources. The most useful technique in creating river beds is to make them stairlike: every now and then make a small step, a small difference in river bed height without it showing on the coast. At that point, add a water source that will not flow over the higher part. The benefit of this is that you won’t get empty river beds, and the river won’t flow in the opposite direction.Cities: Skylines
In the left picture, you can see a simple water flow where water moves from a higher altitude to a lower one. In the real world, one water source would be enough, but not in Cities: Skylines. There are 3 water sources:

1. is providing the water for the whole system and makes a nice waterfall. However, it’s not enough.

2. is regulating the lake levels and makes sure water from the top one is not overflowing.

3. is making sure the water level doesn’t overflow by syphoning incoming water and maintaining levels. However, between 2. and 3. there’s chaos.
Cities: SkylinesThis is where you need to add small sources of water to maintain water levels and control the current.

The picture on the right shows you that I had to create 5 water sources to have a natural flow of water.
Another helpful technique is to follow the topo lines as shown in the picture on the right. I already mentioned Topographic lines toggle mod so you should know about it by now. Topographic lines are the lines that mark differences in elevation on a map. When lines are close to each other, this means that the terrain is too steep. However, this can be used to our advantage when creating water flows: notice how topo lines look around your river beds. If topo lines are close together, this means that flow will be faster. Like in real life, vehicles can go faster down a steep slope (stopping is not covered in this article). If you want to create fast mountain rivers, you need to combine steep slopes and water sources to achieve that realistic feel. If you don’t know how to check the current, press “i” button in the upper left corner and select the “Water flow” option.

Large river beds in Cities: Skylines are not too difficult to make, just make sure you have a consistent current. This is important because of dams and sewage. Hydroelectric dams are the best source of electricity as they are the cleanest and can have the largest output of all. They need a lot of water and can flood large areas if not built properly. This is why constant water influx is important. With the sewage, imagine this scenario: you started your city and put water pumps upstream where the river is coming from and sewage downstream where water is leaving your city (this is the correct way to position your water facilities). After some time, you notice that people are getting sick and moving out of town. After checking, you found out that the river has changed stream and is flowing in a different direction than when you started (it happened to me in one of the vanilla maps). This is causing your poop water to be sucked in by your water pumps and distributed around the city.
You can leave it this way, but don’t expect that the people in your city (cims) will tolerate it, and no amount of medical care can fix that. This is why it’s important to plan ahead and make sure your river has a consistent flow. This rule is valid for any water surface that has a flow.

Waterfalls creation in Cities: Skylines

Cities: SkylinesWaterfalls are pretty easy to make once you have the water mechanics figured out: make the top and bottom lakes, put a water source in each to control the levels, and make an opening in the upper lake (or any water source including rivers) the size of your waterfall. Make sure that you have a vertical cliff between two lakes. It’s also recommended to put the upper water source approximately in the middle of the lake and the lower water source right where the waterfalls so that you have a good current.
In all this, I haven’t mentioned the “Water capacity” option. This affects the current and strength of water coming out of a water source. For lakes and ponds, this value doesn’t make any difference unless you want to create a current. In rivers and streams, it will have a larger role as you can control the current with it. Just make sure it doesn’t go in the opposite direction.

Final Verdict Tips for Cities: Skylines

By now I hope you know a lot more about water placement in Cities: Skylines and mechanics than before this article. There are a few tips that are applicable to any part of this text:

  • don’t plant trees in water as it’s pointless;
  • rocks can obstruct your water flow so be careful where you put them; same with pillars for highways and rail
  • don’t forget you also have sand to decorate your map, so you can make your tropical maps even more attractive
  • if you want to have ship paths on your rivers don’t make them too narrow. If you plan on having bridges where you have a shipping path, make sure you have enough clearance.
  • if you build with mods and custom assets and plan to publish your map in the Steam workshop, make sure you mention them under “Required items”. They will not show up in other people’s games if they don’t subscribe to them and will ask you where you got that custom bridge (if you used it).
    And, as always, you can add more assets to decorate your coast. One good example is River rocks.
    Once you get the hang of these tools, you’ll be creating rivers and lakes in no time. Play around with tools and stay creative.

Written by
Vladimir Mijatović

Distrita own experience
Contributor: MrMiyagi