Let us have a moment of silence for the numerous beers and bottles of Gin that selflessly sacrificed themselves so I could finish this guide.

The equations for calculating water pressures and flow are only guaranteed for vanilla buildings and water infrastructure. Mod buildings shouldn't be an issue, but I cannot guarantee your calculations will be accurate with mod switches and pumps in play, so use them at your own risk.

I don't own Workers and Resources Soviet Republic, which is the property of whoever owns it. I also claim no ownership over any part of the water management features.

I did make this guide though, so I'd appreciate being credited if anyone wants to use it in their work, if they want to translate it into non-English languages (I certainly won't be; sorry, but not really), or whatever they want to do with it.

Since this guide is rather large, you might want to use the search function on steam or a web browser to find what you are looking for.

For whatever reason, some concepts have the same name in the game, so I define the following terms to make it easier to search for specific concepts in this guide:

• Water - Fresh water used by citizens and certain factories.
  
  
• Sewage - Water that has been used by citizens or industry and pollutes when dumped.
  (Named "Waste water" in the game.)
  
  
• Pure Water - A component of water and sewage.
  (Confusingly named "water" in the game.)
  
  
• Pollutants - Another component of water and sewage.
  (Confusingly named "waste water" in the game.)

Since steam's table of contents (as seen on the right of this guide) gets cut off depending on where you are in the guide, I made this section for easily jumping to all of this guide's sections from here.

If you click on a section and it doesn't jump to that section, try reloading the guide by pressing f5 or by clicking on the refresh button at the top left of the screen.

If you click on a link and want to go back to the Table of Contents, you can just click on the back arrow at the top left corner of the screen under the Steam logo.

~ Introduction To Water Management~

Citizen Water Needs
Citizen Water Usage Rates
Industrial Water Usage
Estimating Factory Water Usage

Water and Sewage Characteristics
Treatment Plants
Sourcing Water
Sewage Creation and Disposal
Biomes DLC - Desert Water

Water Pressure/Flow Basics
Sewage Flow Mechanics
Sewage - Inverted Siphons
Tips and Warnings
Planning Water & Sewage Networks
Monitoring for Issues
Identifying Pipe Sizes and Disconnects

Water Tanks of Buildings
Water Pipes
Water Substations
Miscellaneous Water Components
Sewage Collection Components

Water & Sewage Truck Uses
Basic Mechanics and Limitations
Line / Schedule Mechanics
Technical Office Mechanics
When to Use Lines or Technical Offices
Alternative Water Transit Options

Water Gauges and Meters
Tank Indications in Menus
Water & Sewage Overlays
Other Overlays

Tool for Measurement
List of Vehicles and Buildings
Water Records

Mechanics - Pressure
Mechanics - Water Flow
Mechanics - Pipes
Mechanics - Elevation and Storage Heights
Mechanics - Water Tanks
Mechanics - Pumps
Mechanics - Water Switches
Flow Model - Tank to Tank
Flow Model - Pumped Flow
Flow Model - Water Switches

Equations - Water Quality & Treatment
Equations - Water Pressure & Flow
Equations - Water Flow Models
Equations - Sewage
Water Calculators
My Other Guides
Remaining Questions to Answer
Comments

Ways to translate this guide are discussed here.

Translated by Google; sorry for butchering your language.

English
If you right click on the sides of this page, you can obtain a URL that you can copy and paste into your web browser. Most web browsers have built in translators or apps that can translate pages into your native language for you. Chrome for example can translate pages simply by right-clicking the page and selecting "Translate to [your language]" from the pop up menu.

Русский - Russian
Если щелкнуть правой кнопкой мыши по бокам этой страницы, вы сможете получить URL-адрес, который можно скопировать и вставить в свой веб-браузер. В большинство веб-браузеров встроены переводчики или приложения, которые могут переводить страницы на ваш родной язык. Например, Chrome может переводить страницы, просто щелкнув страницу правой кнопкой мыши и выбрав «Перевести на [ваш язык]» во всплывающем меню.

Polski - Polish
Jeśli klikniesz prawym przyciskiem myszy po bokach tej strony, możesz uzyskać adres URL, który możesz skopiować i wkleić do swojej przeglądarki internetowej. Większość przeglądarek internetowych ma wbudowane tłumacze lub aplikacje, które mogą za Ciebie przetłumaczyć strony na Twój język ojczysty. Na przykład Chrome może tłumaczyć strony, klikając stronę prawym przyciskiem myszy i wybierając „Przetłumacz na [twój język]” z wyskakującego menu.

Čeština - Czech
Pokud kliknete pravým tlačítkem na okraje této stránky, můžete získat adresu URL, kterou můžete zkopírovat a vložit do svého webového prohlížeče. Většina webových prohlížečů má vestavěné překladače nebo aplikace, které dokážou přeložit stránky do vašeho rodného jazyka za vás. Chrome může například překládat stránky jednoduše kliknutím pravým tlačítkem na stránku a výběrem „Přeložit do [váš jazyk]“ z vyskakovací nabídky.

Deutsch - German
Wenn Sie mit der rechten Maustaste auf die Seiten dieser Seite klicken, erhalten Sie eine URL, die Sie kopieren und in Ihren Webbrowser einfügen können. Die meisten Webbrowser verfügen über integrierte Übersetzer oder Apps, die Seiten für Sie in Ihre Muttersprache übersetzen können. Chrome kann beispielsweise Seiten übersetzen, indem Sie einfach mit der rechten Maustaste auf die Seite klicken und im Popup-Menü „In [Ihre Sprache] übersetzen“ auswählen.

Change all mentions of "waste water" to "sewage," and rename the components of water/sewage from "water" and "waste water" to "pure water" and "pollutants."

Fix the water flask tooltip bug for "sewage quantity" (only visible with cheats enabled); it should read: water tank level or something similar.

Get rid of the "max flow at max pressure" indication or fix it; it is misleading at best.

It would be far better to always and automatically merge connected pipe segments into one pipe segment if they are all constructed (the join tool is a good start though). You already don't allow pipes of different sizes to be connected (which is good), and mousing over gauges only highlights the nearest pipe segment, which makes tracing out pipes in clustered networks or tracing a pipe out to areas far away more difficult. With one pipe segment, the entire pipe will always be highlighted, making it much easier to discern what pipe is connected to what.

Change the Resource Overlays for "Water" and "Sewage" so that the pure water and pollutant components of water are not displayed in water and sewage vehicles.

This section serves as a primer for the water and sewage systems in the game. Certain exceptions have been made to keep this introduction simple, but they will be discussed later in the guide.

Simulating water and sewage in your game will have the following issues to consider:

• Citizens will require high purity water to be happy, healthy, and productive.
  
• Some industries now require water as an ingredient and will output sewage. Building large enough water and sewage systems can be quite taxing for large industries or large complexes of industries.
  
• Treating water and sewage will require chemicals, which can become quite expensive.
  
• Designing efficient water distribution networks can be difficult because water flow mechanics are rather complex. Overbuilding water networks is somewhat safer, but more expensive.
  
• Sewage has to be dumped into water (unless you use mods), which will make handling the sewage of towns and certain industries far from water expensive or difficult.
  
• Sewage creates pollution where it is dumped, which will prevent the use of the land around its discharge point for residential use, tourism, or sourcing fresh water. Like the pollution from heating plants, sewage from large cities can eat up a lot of residential land if dumped locally, but you can treat it to reduce pollution or zone your city carefully to avoid placing residences in pollution.

Not really. Water management increases the difficulty of the game; it does not provide you with an easy income or any real benefits.

The closest thing to a benefit would be that selecting a water well and mousing over an area will give you a great (and free) point indicator of "low level" pollution, whereas the actual pollution monitor only gives you an idea (dark green dots do not necessarily mean no pollution is present).

The water distribution system in this game is a pressure based system, which means that water is pushed through pipes in any direction from points of high pressure to points of low pressure. Pressure and thus flow can be raised by pumps or by placing sources higher than the water's destinations, but pressure is not exerted past buildings, so you will have to provide pumps or include a drop in height between each building to maintain flow.

Citizens need potable water for a few reasons:

• Workers need drinking water or their output will be halved.
  
• Residents need water or they will become unhappy and lose loyalty.
  
• Citizen health is also affected by water quality, and they will refuse to drink it below a certain point.

There are basically three types of buildings when it comes to water management:

• Water sourcing buildings (wells, surface pipes, customs, treatment plants)
  
• Distribution buildings (pipes, pumps, switches, un/loading stations, substations, storages)
  
• Consumer buildings (any building citizens work or live in, certain industries)

Water sourcing buildings are where water management begins. Water is created at sources and treated at treatment plants to whatever required quality before being sent to consumers. To reduce the amount of treatment required to raise water quality, water sources should be placed in pollution free areas. Treatment plants can be used to raise quality if needed, but should generally be avoided if possible to reduce the usage of chemicals.

Consumer buildings are the places water is consumed in and thus the end of the water system. Most buildings where water is consumed will have a water tank for the building for its citizens to draw from. Industries that need water for production may have a separate tank for industrial water, but not always.

Distribution buildings are simply the infrastructure that moves water around from sources to consumers. Pipes connect the buildings to enable water flow between them, water towers and reservoirs store water, pumps add pressure to the pipes they connect to, switches allow paths of water to branch out to different consumers, and substations connect most buildings to the water system. Some industrial buildings also have a pipe connection to take in lower quality water meant for industrial purposes rather than citizen consumption.

Trucks can also be used to move water from sources to consumers, but they will struggle to move large quantities of water. For starting towns they are ideal because they can handle the small quantities required, need little time to setup, and will cost less than installing a water system. Later on you will want to switch to a pressurized water system to save money on fuel and to reduce traffic, but ensure you finish your sewer system before enabling your water system.

The basic goal of a sewage system is to remove sewage from factories to keep them functioning and from residences to keep citizens from dying from pollution, and to dump the sewage somewhere else. Dumping sewage always results in pollution, which will prevent the use of nearby land for residential use, tourism, and sourcing fresh water, but this can be reduced by treating sewage before discharging it.

The sewage system in this game is a gravity based system, which is to say that sewage will only flow downhill. This requirement for all sewage to flow downhill means that you need to build your sewage system with buildings at progressively lower elevations or use pumps to achieve a high enough slope for sewage to flow. Unlike water, flow is independent of any variable save the sewage pipe's flow limit; so long as the pipe is sloped enough, sewage will flow up to the pipe's flow limit.

Compared to water, sewage infrastructure is much more simple. Most buildings will dump their sewage into sewer tanks which are joined into a sewer main with "sewage switches." This sewer main flows into a discharge point where the sewage is dumped into a body of water, polluting the area in the process. If desired, the sewage main can be routed through a treatment plant first to reduce the pollution of the sewage sent to the discharge point, but treatment plants can become a bottleneck for your sewage system.

Like with water, trucks can be used to remove sewage from buildings, and can continue to serve as a backup when the sewer system backs up for whatever reason, but trucks will struggle to handle the sewage created by a pressurized water system.

If you want to upgrade your save to water (or any other feature with locked buildings) but don't want to deal with rushed constructions, scramble water trucks to deliver water, nor resort to using auto-buy, you can instead use Landscaping Mode to select and place whatever water and sewage buildings you want without having to enable the water management feature.

You can also just enable water management, plan whatever, and then disable water management, and planned water/sewage infrastructure will remain and can be built with the feature disabled; however, you will have to reload your save every time, which with the number of mods some of you have, may take 5 or more minutes each time whereas landscape mode does not require reloading (usually; see below).

This is technically a map editing mode, but placing any buildings in it will use the resources in your republic (including cash) to build. We are just using it to gain access to buildings locked by disabled features.

To start, you will need to select whatever construction method you want to use (manual or auto-buy with rubles/dollars), as you will not be able to select this once you enable landscaping mode, and then enable cheats by pressing C, H, and E simultaneously until you get a message.

Then open the settings menu and click on the button labeled "General debug/cheat functions" and check the box next to "Landscape editor mode." The GUI should change a bit, but you can ignore all of that and just select whatever water/sewage buildings you need from the bottom selection bar and place them as needed.


.
Once you have finished placing all the buildings you want, you can leave landscaping mode by simply unchecking the box next to "Landscape editor mode."

When you feel your republic is ready, enable water management and play as normal.


Sometimes when you switch to landscaping mode, the game will automatically enable the day/night cycle and usually then switches to nighttime. The only way to fix this is to change the day/night cycle setting and then change it back to whatever you had it at, which will require two reloads. If you already have the day/night cycle enabled, then this bug doesn't matter.

In this game, water is used for two overall purposes:
• As "Drinking Water" - Potable water for citizens to drink, bath, or do whatever with.
• As "Industrial Water" - Used in an industrial process, like making concrete or alumina.

Both will be discussed in the following sections.

The reasons why you should provide citizens with water are discussed here.

Citizens need water for a few reasons:
• No water at home lowers health a lot; like 10% to 20%. (Wash your hands everyone.)
• No water at home significantly lowers happiness and loyalty of residents.
• Poor quality water reduces happiness and health.

Water at home is required or citizen happiness and loyalty will eventually drop below 50%, even on easy citizen reaction settings, but inactive native populations will not require water until they are activated.

All of these effects take time to manifest, so you'll have some time to fix malfunctioning water setups before your citizen's stats fall that much, but unfortunately there are no alerts for a lack of drinking water or for overflowing sewage, so if you do not manually monitor your water and sewage systems, your first indication will likely be an alert for low health, low happiness, or low loyalty.

Delivering low quality drinking water (< 97%) will start to impact citizen health, with qualities below 95% starting to affect health significantly. Do not deliver less than 97% unless you want to reduce your population size, and ideally you would supply 99% quality water to maximize citizen health.

Lowered health is bad because more citizens will need to visit the hospital, especially if you also expose them to pollution or if you have an epidemic. Citizens with lower health also live shorter lives, are less productive, and have fewer children.

Not having drinking water at a workplace halves its workers' productivity:
• Factories without water have their maximum production percentage and output halved.
• Service buildings' visitor capacities are halved.
• Power plant and heating plant capacities and outputs are halved.

The only exceptions to this are construction sites, farm fields, and gravel quarries, which do not require drinking water at all, and the radio and TV stations, whose ratings seem to be unaffected (there may be another consequence I am unaware of though).

Even foreign workers will need drinking water or their output will be halved.

Factors related to citizen water usage are discussed here.

This depends on three factors:
• How often are they in a building?
• What citizen type are they at the time?
• Is the building's water tank pressurized or not?

Each factor is discussed below.

If citizens are not inside a building, then they will not be using water nor creating sewage, which means that the average water usage rate will depend on the average number of citizens present in the building.

This makes estimating residential and hotel water usage difficult because accurately predicting how many people are present at these places is hard. Since the length of a day for citizens and tourists can vary quite a bit, so does the time they spend in their home/hotel, and so does the number present in the apartment/hotel at any time. Even if you isolate a full apartment building to force all of its residents to remain home, they may not all be using water as some will be trying to find work or a need before they give up.

For estimating the water usage of residences and hotels, I would recommend that you assume that at least a third of the "Maximum daily water consumption" listed for an apartment building or hotel will be used at any time, but also that you install a system that can sustain at least two thirds of their rated maximum water usage for a short while (in case usage spikes for a short period, the water will be refilled).

Such a system may look like this:
• A water tower has a water supply that can supply half of the maximum water usage.
• The pipes and switches from this water tower can sustain 2/3 of the maximum water usage.
• The water tower has enough capacity to cover spikes of higher usage for at least a few days.

This way, hotels and apartments are covered for spikes in water demand, and the water tower can refill when usage rates normalize. Normally you won't see these spikes unless a bigger problem occurs, like a failure of public transportation forcing a lot of people to remain home or in their hotel. Water usage spikes above 66% of the maximum usage rate will be also covered by the building's own internal water tank for a while too. If a building really needs extra water, then you can also have water trucks on standby in a technical services office.

For workers in any building, I would recommend planning for slightly above 100% of the water usage rate or whatever percentage you plan to use it at, as you pretty much want the same number of workers in a building at all times, which will result in a more or less constant usage of water. Any dips in staffing will give adequate time to replenish the building's drinking water tank, but you might want a little more capacity just in case.


While in specific buildings, citizens will also vary their water usage depending on their current "citizen type." While spending time in a building, citizens will consume water and generate sewage at the following rates depending on their citizen type:

• Citizens use 0.045 m³/day each while in their homes and not looking for work/school/needs.
  
• Workers consume 0.02 m³/day each when at a workplace.
  
• Tourists seem to use about 0.367 m³/day each at their hotel.
  
  
• Citizens and tourists who visit service buildings do not seem to consume water at all.
  
• Babies do not seem to consume water at all.
  
• Students do not consume water at schools nor universities.
  
  
• Children and 21+ adults living with parents seem to consume 0.045 m³/day each at home.
  
• Students living in a dorm use 0.045 m³/day each when at their dorm.
  
• Orphans use 0.045 m³/day each when in their orphanage.
  
• Prisoners use 0.045 m³/day each when in their prison.

It is possible that children consume water at rate proportional to an adult's water usage rate depending on their age, such as they do with food and meat, but this is difficult to confirm (i.e. I am lazy) with the unsteady water usage rates of a building and averaged ages of children in said building.

Keep in mind that citizens are not constantly using water while at their home, if they still plan on going out for work or to satisfy needs, they may not be using water.


The final factor on citizen water usage is whether the building's drinking water supply is pressurized or not. If the drinking water is pressurized, then citizens will consume 10 or 20 times as much water as if it were unpressurized, depending on their citizen type.

For unpressurized water, citizen usage rates will reduced:
Whether a building's water supply is "pressurized" or not is a binary check. They either have no pressure and citizens reduce usage rates, or they have pressure and use the full usage rate, even if the pressure is almost zero.

Buildings will not have pressurized drinking water unless served by at least one substation that is pressurized, and substations are not considered pressurized if they are connected by a pipe to:
• Nothing.
• A pump that is turned off by the player or due to a lack of power.
• A building that is completely out of water and is not receiving nor generating any water.
• A building that cannot exert enough pressure for flow to occur, even if it has water.

A substation connected by a pipe to a water tower without its valves open can still be counted as pressurized, as water towers always exert pressure so long as they have water within them, even if water cannot flow at all.


Industrial usage of water does not change with water pressurization, except as a result of increased worker productivity from supplying the building with drinking water. For example, chemical factories will always use the exact same amount of water to make a ton of chemicals; they can just make more tons a day with ample drinking water supplied to their workers.


So with the big disclaimer of it depends, you should expect about 100 citizens to use 1 m³ per day. Because citizens create an amount of sewage equal to their water usage, you can also assume that about 100 citizens will create 1 m³ of sewage per day.

You should keep an eye on your water and sewage systems and include a buffer in your designs though, as these rates can vary with citizen activity (like anything causing them to stay indoors more often or longer). This also does not include industrial water usage and sewage generation, so plan for those separately.


Sewage output for a republic where all water is used for citizens.

Since it takes about 100 citizens to use 1 m³ of water per day, each treatment plant can support a different amount of population:
• Water Treatment Plant (small) ~12,000 citizens
• Water Treatment Plant (big) ~30,000 citizens
• Sewage Treatment Plant (small) ~16,500 citizens
• Sewage Treatment Plant (big) ~44,000 citizens
• Sewage outlet ~50,700 citizens (assuming three large pipes are connected with max flow)

This is not accounting for any water for or sewage from industry though, and you should leave a buffer to account for slightly different citizen usage rates (these can vary a bit).

Compared to citizens, industries are much more simple. The amount of water they use and the quality of water they demand are rather constant and easy to find out, so there are really only a few things to know about industrial water usage:
• How water behaves as an industrial good.
• How Industries handle water by its quality.
• That livestock will consume water when stored.

Some factories will consume water to make another product, such as food, but water has some unique characteristics compared to other cargo:

• Water has a quality rating, and factories can only use water of a high enough quality or they will stop working.
  
  You can find out the quantity and quality a factory needs per "day" by opening its menu or mousing over it in the construction window, and looking under "Consumption at maximum production:"
  
  
  .
  Factories will consume water for industrial purposes in proportion to the amount of product the factory creates. For example, every 20 tons of food made by a vanilla food factory will require 8.5 tons of water, regardless of the food factory's production %.
  
  Like any other input good to a factory, if you cannot supply enough water for a process, the building's average production % will suffer.
  
  
• Water is also unique in that, unlike goods moved over conveyors, pipelines, or factory roads, water cannot be pulled nor pushed through pipes by factories for production. You will have to have a water system pushing water into (or a convoy of trucks constantly filling) the factories' internal tanks to maintain production.
  
  This also means that if you want to use trucks to supply water or remove sewage, you will have to keep one of the industry's vehicles spots open for the truck to use.
  
  
• With one exception, water does not disappear once an industry uses it; instead, it becomes sewage water, which also must be removed from the factory to keep it working.
  
  Currently the concrete plant is the only industry that does not create sewage from an industrial process using water, but it will still produce sewage from its workers (if they get drinking water).

With one exception (gravel quarries), all factories and mines will require drinking water for their workers, which means all factories and mines (except gravel quarries) will have its own water tank to store drinking water. This drinking water tank can only be replenished from a water substation or by a water truck.*

Of the factories that require water for production, they may or may not have a separate water tank and a pipe connection for industrial water, depending on the quality they specify for the industrial water they use:

• If they need water of a quality similar to drinking water, they will only use the drinking water tank for production and for workers and they won't have a pipe connection.
  → Example factories: Food factory (97%), Distillery (95%), and Livestock farm (93%).
  
  
• If they need water of a lower quality for production, then the factory will have another tank for lower quality water, but while these factories will still draw drinking water from a substation (or a water truck*), they will only replenish their industrial water through a pipe connection somewhere on the edge of the factory or by a water truck.*
  → Example factories: Alumina plant (75%), Chemical plant (67%), and Fabric factory (85%).

If the factory has separate tanks for industrial water and for drinking water, then it will also have a separate tank for the factory's industrial effluent, which will not drain to a "Sewage tank" substation but through a direct connection to a sewer system. A waste water truck can also take it away.*

For some reason, dumping drinking or industrial water will fill the industrial sewage tank, not the drinking water tank's corresponding sewage tank.

*See the Truck Mechanics section for info on trucks; they have some restrictions on the types of tanks they can service.


The main reason factories with low quality water requirements have separate connections for water and sewage is so you don't have to waste high quality drinking water meant for workers on processes that do not require high water quality. Keep in mind though, that you will need extra pipes or water treatment plants to supply another quality of water.


Once "created," livestock will need to consume water or they will start "dying off" (the tonnage of livestock stored there will decrease over time) but only while in livestock farms or halls; while in transit or in a slaughterhouse, livestock do not consume water.

One ton of livestock will require about 0.05 m³/day of water of at least 93% quality to keep them alive (i.e. prevent their tonnage from going down). Providing water of lesser quality will slow the loss rate, but not eliminate it.

As a sop for the player, livestock will generate bio-waste if you have waste management enabled, which will provide a good source of fertilizer for farming. Still, it is much cheaper to just buy over 10,000 tons of bio-waste than it is to build a livestock hall and supply it with livestock and water.

While we're discussing the loss of livestock, you should also know that meat will decay away if stored in a building that lacks power, though the decay rate isn't nearly as fast as the loss of livestock is without water.

This is pretty easy to do, but it requires a little math.

Factories use both drinking water and industrial water, but the rates for these are listed in two places:

• The "Max daily water consumption" listed in the building selection bar pop-ups shows how much drinking water is consumed per day at full staffing.
  
• The "Consumption at maximum production" lists how much water is used for industrial purposes per day at 100% production.
  
  .
  If the factory doesn't use water for its production, then the factory will only draw water up to the "Max daily water consumption" listed in its pop-up, but if the factory has both, then you will have to add in the amount of water used for its industrial process. For example, the fabric factory uses 2 m³/day of drinking water and 11 m³/day of water for industrial processes; in total, it uses 13 m³ of water a day.
  
  Since worker productivity can exceed 100%, you can run factories at 100% production percentage without maxing out its staff. With this in mind, you could provide less water flow to the factory, but this is probably not worth it; a little extra flow is needed to refill the factory's tank should water service be suspended for whatever reason, and the savings won't be that great anyway.

How water quality works, where to get water, where to dump sewage, how to improve water quality, and how to reduce sewage pollution is discussed here.

I think everyone has encountered water in their life and hopefully knows what sewage is without firsthand experience, so I'll limit this definition of water and sewage to the important bits.

In this game, water and sewage are defined by two characteristics:
• "Freshness" - Has the water been used? If yes, it's sewage; if not, it's "water."
• Quality level - Basically a measure of how pure or dirty water or sewage is.

The only real difference between water and sewage is whether it has been used or not. Sewage is water that has been used by a factory or a citizen and is no longer "fresh" enough to be used again and thus it has to be disposed of somehow, while new "fresh" water has to be obtained to replace it.

All the other characteristics are identical:

• Water in = Sewage out: Whenever water is consumed and converted into sewage, it will be the exact same amount, even if you would expect some water loss from industrial processes or from evaporation.*
  
  
• Quality = Pollution %: This is explained more below, but both are calculated in similar ways with the same variables. Quality requirements and pollution % are also assigned in the same way.
  
  
• Water and sewage load and unload at the same rates and have the same "bulkiness."

*The only current exceptions are the concrete plant, which doesn't produce industrial sewage, and fountains, which generate no sewage at all.


Essentially, water quality is the measure of how pure a sample of water is and sewage pollution % is how dirty a sample of sewage is.

In more detail, the water and sewage (a.k.a. waste water) in this game are actually mixtures of two substances, which are also confusingly labeled "water" and "waste water." To avoid confusion, I will simply refer to these as "pure water" and "pollutants."

You can see the composition of any water or sewage sample in a building by enabling cheats (press c, h, and e simultaneously until you get a message) and then pressing and holding "Ctrl - b," which will switch the display to show the amount of each component present:

.
These components, "pure water" and "pollutants," are the basis for a water sample's quality and a sewage sample's pollution %.

Quality is simply the percentage of the "pure water" present in a sample of water:

Quality = W ÷ V × 100%, where:
• W = volume of "pure water" in the sample.
  
• V = volume of the entire water sample.

Pollution % is like the "quality" of sewage, but instead of measuring the amount of "pure water," it measures the amount of "pollutants" present in a sample of sewage:

Pollution % = P ÷ V × 100%, where:
• P = volume of "pollutants" in the sample.
  
• V = volume of the entire sewage sample.

If we plug in the numbers for the food factory's water and sewage above, we get the reported quality and pollution % of its water and sewage:

• Quality = W ÷ V × 100%.
  = 11.78 m³ ÷ 11.90 m³ × 100%
  = 98.99% (98% is reported)
  
  
• Pollution % = P ÷ V × 100%.
  = 3.86 m³ ÷ 7.76 m³ × 100%
  = 49.74% (49% is reported)

Knowing how to calculate the amount of pollutants in water is useful for planning out water treatment and the pollution from discharging sewage, and can be done by rearranging the equations above:

• Volume of pollutants in water:
  P = (100% - Quality) × V ÷ 100%, where:
  • P = volume of "pollutants" in the sample.
  • V = volume of the entire sewage sample.
  
  We use (100% - Quality) because we want to measure pollutants, not pure water.
  
  
• Volume of pollutants in sewage:
  P = Pollution % × V ÷ 100%, where:
  • P = volume of "pollutants" in the sample.
  • V = volume of the entire sewage sample.

Both water and sewage can be treated at their respective treatment plant to raise water quality or lower sewage pollution %. This section will discuss how they work.

Both the water and sewage plant have a "desired water quality" setting which determines the minimum quality of the water they will release. For sewage, just remember that pollution % = 100% - quality when you are adjusting this setting.

Water treatment plants will also create drinking water for their workers regardless of what their quality setting is at.

Treatment plants have three limits to the amount of water they can process:
• "Maximum flow of processed water."
• "Maximum amount of toxic liquids to be eliminated."
• Worker productivity and staffing.

The first limit is pretty obvious; "Maximum flow of processed water" is how much water can flow through the treatment plant. Regardless of the quality of the water (or pollution % of the sewage) you are running through it, this is the most volume per day that can go through the treatment plant.

The second limit "Maximum amount of toxic liquids to be eliminated," is somewhat misleading; instead of eliminating "toxic liquids" (pollutants), treatment plants will actually convert it into pure water, so there is no loss in volume with treatment. This limit also determines how much water it can process in relation to how much the quality needs to be increased by.

The third limit is how high the production % the treatment plant can get to, which is dependent on how well you can maintain staffing at the treatment plant and the average productivity of the workers working there. Even if you can keep 100% staffing at all times, your treatment plant will only be able to work at 70% if its workers have an average productivity of only 70%. Usually it is safe to plan for 80% average staffing and whatever productivity you feel you can support.


Because treatment plants can only remove so many pollutants a day, the difference between the treatment plant's "desired water quality" and the quality of the incoming water/sewage will determine how much water/sewage the plant can process.

For example, increasing the quality of 100 m³ of water at 80% to 99% would require removing 19 m³ of pollutants. For a small water treatment plant, this would take about a day and a half to do because it can only process 13 m³ of pollutants per day. This would also limit its water outflow to about 68 m³/day instead of its maximum flow rate of 120 m³ of processed water per day.

The equations below can be used to estimate the maximum flow or maximum rise in quality a treatment plant can support for a given desired quality and input quality:

• Maximum quality rise while maintaining maximum flow of processed water/sewage:
  ▲Q = P ÷ F, where:
  • ▲Q = maximum rise in quality or pollution %.
  • P = maximum volume of pollutants the plant can remove per day.
  • F = maximum volume of water/sewage the plant can process a day.
  
  
• Maximum volume of water the plant can process a day for a given rise in quality:
  F = P ÷ (▲Q), or F = f, whichever is lower; where:
  • F = the expected flow of processed water/sewage from the treatment plant.
  • f = the maximum flow rate limit of the plant; flow cannot exceed this limit.
  • P = the volume of pollutants the treatment plant can remove a day.
  • ▲Q = the change in water/sewage quality.

Remember that the quality of sewage is equal to 100% - pollution %:
• Setting an 85% quality goal at the treatment plant is setting the desired pollution % to 15%.
• ▲Q = incoming pollution % minus outgoing pollution % = outgoing quality - incoming quality.


Here are some examples to calculating how much volume a treatment plant can process for various input water quality or sewage pollution %.

A big water treatment plant can process 300 m³ of water a day, but only remove 30 m³ of pollutants a day:

• The maximum rise in quality while processing 300 m³ of water a day is 10%:
  ▲Q = 30 m³/day ÷ 300 m³/day = 10%.
  
  
• If the input water has a quality of only 73% and the target quality is 99%, then the treatment plant would have to reduce its output flow to remove all of the contaminants:
  F = 30 m³/day ÷ (99% - 73%) = 115.38 m³ of processed water a day, or about 38.5% of the plant's maximum flow of processed water.
  
  
• If the input water has a quality of 95% and the target quality is 99%, then the treatment plan could output its full capacity of processed water:
  F = 30 m³/day ÷ (99% - 95%) = 750 m³ of processed water a day, which is reduced to its maximum flow limit of 300 m³/day.

A big sewage treatment plant can process up to 440 m³ of sewage a day, but only remove 220 m³ of pollutants per day:

• The maximum change in pollution % while processing 440 m³ of sewage a day is 50%:
  ▲Q = 220 m³/day ÷ 440 m³/day × 100% = 50%
  Since the minimum pollution % a treatment plant can output sewage at is 15%, you can input sewage with a pollution % up to 65% without any loss in the maximum processing rate.
  
  
• For sewage with a pollution % of 78% and a target outlet pollution % of 15%, the treatment plant could only process 349.2 m³/day of sewage, which is about 90.8 m³/day less than its maximum flow limit.
  F = 220 m³/day ÷ (78% - 15%) = 349.2 m³/day
  
  
• If sewage with a pollution % of 30% came in and the target outlet pollution % is 15%, the treatment plant would be limited to its maximum flow limit for processed water, even though the plant is nowhere near its pollutant removal limit:
  F = 220 m³/day ÷ (30% - 15%) = 1,466.67 m³/day, which is reduced to the treatment plant's maximum limit of 440 m³/day.

Chemicals are used at a rate based on the amount of pollutants removed rather than the amount of water or sewage flowing through the treatment plant.

Chemical usage can be estimated with these equations:

• R = C × P ÷ W, where:
  • R = The rate that chemicals are used at, in tons per day.
  • C = The treatment plant's rate of chemicals consumption at maximum production.
  • P = The volume of pollutants removed per day, in m³/day.
  • W = The maximum volume of pollutants the treatment plant can remove each day.

This equation can be expanded to the factors shown in the treatment plant's menu:

• R = C × V × (▲Q) ÷ W, where:
  • R = The rate that chemicals are used at, in tons per day.
  • C = The treatment plant's rated consumption of chemicals at maximum capacity.
  • V = The volume of water flowing through the treatment plant, in m³/day.
  • ▲Q = The rise in water quality (remember to convert ▲Q to a decimal: 1% = 0.01).
  • W = the Maximum amount of pollutants the treatment plant can remove each day.

Larger treatment plants are generally more efficient, but they cost a lot more to build:

In most cases, I would recommend building the smallest plant you can get away with.

• The larger water plant uses ~18.53% less chemicals per m³, but the savings won't cover the increased construction costs for at least a year or so. This extra money could be used to increase the republic's income or industry for better growth while having a bit more expenses.
  
• Except for roleplay, the only reason to treat sewage is to preserve unpolluted land, which the small sewage plant is better at doing.

Like all the resources in the game, you basically have three options to get water:
• Produce it yourself.
• Purchase it at a customs house.
• Purchase it via Auto-buy.

Unlike all the other resources in the game, you also need to worry about quality, which will differ among these methods of procurement, and distribution is also a bit more involved with auto-bought water.

As far as the game cares, there are three types of water sources:

• Wells - Buildings that draw water from the ground.
  • Produces high quality (95%) water in undeveloped, pristine areas.
    
  • Nearby buildings and pollution reduce a well's water quality to as little as ~78%.
    (All buildings within ~200m will degrade a well's quality, even farm fields, other wells, and itself).
    
  • Good for sourcing drinking water or water for industries with a high quality requirement.
    
  • Wells have the $TYPE_MINE_WATER tag.
    
  • The small well is also fire proof.
  
  
• Surface inlets - Buildings that draw water from a body of water.
  • Produce decent quality (77%) water in pristine areas, but will lose a little quality with pollution (to a minimum of ~73%).
    
  • Quite cheap for the amount of water it produces, but needs a pump.
    
  • Despite being rated for 150 m³/day, ~128 m³/day is more likely due to pipe/pump limits.
    
  • Good for providing water to industries that don't need high quality water.
    
  • Surface inlets have the $TYPE_MINE_WATER_SURFACE tag.
  
  
• Factories (mods).
  • The game supports the production of water (and sewage) like any other good in a factory, but since there are no base game buildings that work this way, it can only be seen in some mods.

Radiation reduces water quality quite severely, to a minimum of 40% for both water source types. This can completely disable a nuclear power plant from operating if it caught fire earlier and its water source is nearby, as it needs at least 60% quality water to function.

There are two wells in the base game (the Early Start DLC adds more); a small well which is fireproof and does not need workers but only produces a small amount of water, and a large well which produces a lot more water but needs a small amount of workers and is not fire proof. The small well can be built in a remote area and be forgotten since it doesn't need workers or fire protection, but the large well can extract more water in an area without lowering quality, meaning you need to devote less space to producing high quality water.

There is only one surface inlet in the game, and it is pretty cheap compared to the small well (like 1/15th as costly) with more than twice the output of water, but it is not fire proof so fire protection must be provided.

Somehow a steel pipe on a concrete block is highly flammable.

Selecting a well or surface pipe usually comes down to the quality requirements of whatever you plan on supplying water to:

• Drinking water and industries with high quality water will need treated water, so to minimize the chemicals needed, a well in a remote, undeveloped, and unpolluted area is usually the best option. Even if the extra piping is expensive, the money saved on chemicals will usually be well worth it.
  
  
• Industries with moderate water quality requirements (above 77%) can also use untreated water from wells to save on chemicals, but they may have to be built far away to avoid an excessive effect of pollution on the well's water quality, which will still require a lot of piping.
  
  
• Industries with lower water quality requirements (below 78%) can use untreated water from a well right next to them or they can use water from a much cheaper surface inlet to save money; especially if the required quality is below 73%, as the surface inlet can be built right next to a polluting industry with minimal amounts of piping.

With water trucks, you can purchase water at a customs house and deliver it to whatever buildings you want. Exactly how is explained in the Truck Mechanics section, but basically this involves a technical office or a line for water trucks.

All water bought at customs houses will have a water quality of 99%, which can be used in all industries and for drinking water without issue. This will also slightly decrease the fee paid for water, as the price displayed at the customs house is for pure water; since you get 99% quality, the water is only 99% of the price for pure water.

Customs house advantages:

• No construction is required - This is great for starting a new town or industrial area quickly, as all you need to do to provide water is place a free technical office, designate the customs house as its water source, and put a water truck in it. No need to build pipes, water wells, nor treatment plants.
  
• Save starting money - It is far cheaper to buy a water truck and import water for a couple years than it is to build a complete water system, especially for spread out buildings.
  
• Customs houses can also serve as an emergency backup for water, but trucks will likely struggle to supply enough water to meet a pressurized water demand, and there is no way to depressurize a substation short of deleting the pipe connected to them.

Customs house disadvantages:

• Water trucks will add to customs house traffic, especially if you have pressurized substations, a lot of population, or you try to supply industries at full production.
  
• Trucks will have a rather limited throughput, so sustaining industries that use a lot of high quality water can require a quite a few water trucks, especially over several km. The cost of these trucks will not be insignificant either.

If you don't play with realistic mode enabled, then you have the option of auto-buying 100% quality water directly into industries and water storage buildings. No water treatment is required and every industry can use it, but you cannot depend wholly on auto-buy for water for a couple reasons:
• Drinking water cannot be bought directly at buildings, so you will have to distribute it somehow.
• The delivery fee can get quite expensive as you get far from the border.

Because you cannot auto-buy drinking water at individual buildings, you will have to auto-buy water at a water storage building and from there, distribute it with pipes to substations or use water trucks to bring it to buildings.

Personally, I don't see the point in auto-buying water except in emergencies, as since you need a water distribution system anyway and since auto-buying has a hefty delivery fee the further from the border you are, you might as well just build a water well and a treatment plant instead.

This section discusses the origin of sewage and how to dispose of it.

All water turns into sewage when used, except for fountains and for making concrete (it just disappears). There is also no loss of volume in the conversion of water to sewage, so except for fountains and concrete plants, the amount of water entering a building is the same as the amount of sewage leaving it.

Sewage cannot be imported through vanilla means (and probably not with mods either).
Apparently sewage can be imported now on some versions, which may include the current version.


The pollution % of sewage is determined by whether it was used by citizens or by an industry. Sewage from citizens is always created with a pollution % of 52%, while sewage created by an industry will have whatever pollution % the building is set to in its config file.

For example, the water used by the food factory will become sewage with a pollution % of 24% while water used by the alumina plant will become sewage with a pollution % of 71%. You can find a list of all sewage emitting industries' pollution % settings in the Equations - Sewage section.


Keep in mind that the sewage of workers and industries will typically be collected together, which will skew the combined sewage pollution % to that of citizens' sewage pollution %. The sewage from a food factory and its workers will be between 24% and 52% while the sewage from an alumina plant and its workers will be between 52% and 71%.

The pollution % of mixed sewage can be predicted with the following equation:

• M = Σ (Vn × P%n) ÷ Σ Vn, where:
  • M = Mixed sewage pollution %
  • Σ (Vn × P%n) = The sum of each volume of sewage (Vn) times its own pollution % (P%n).
  • Σ Vn = The sum of all sewage volumes.

For example, at full production a livestock farm expels 12m³/day of industrial sewage with an pollution percentage of 47% and 2.30m³/day of worker sewage with a pollution % of 52%.

Plugging these numbers into the formula yields: (12 × 47% + 2.30 × 52%) ÷ (12 + 2.30) = ~47.8%, which will show up as around 48% at the sewage switch/tank.


Sewage can be disposed of by either dumping it into a body of water or exporting it at a customs house.

Dumping sewage into a body of water is the only vanilla option for a republic to dispose of sewage without paying a third party, which means all sewage systems have to end at a body of water. This can be difficult to do for areas that are far from a body of water because you either have to lay kilometres of sewage pipe or you have to lower the land below 0 meters (sea level) to create a small lake, which can end up looking like a huge crater for elevations of 20 or more meters.

There are mod buildings that dispose of sewage without being close to a body of water, but this will remove the challenge of building large cities and certain industrial complexes (like chemicals) far from bodies of water and at high elevations, and since the point of the water management system is to add requirements like these to shake up the game, I will not recommend these mods.

You can dump sewage carried by trucks too, but they will have to unload their sewage at a sewage unloading and loading station (or a treatment plant) that is connected to the discharge point; they cannot unload sewage directly at the sewage discharge.


Exporting your sewage is another option, and one that I recommend early on since all that is needed is a single cheap sewage truck for your citizens; no infrastructure need be built, which saves a lot of money and time setting up a starter town that can be spent on increasing the republic's income for faster growth. You can also add sewage substations to concentrate sewage to make it easier for sewage trucks to take full loads.

The price for exporting sewage can be misleading though. The actual cost to export sewage at a customs house will depend on the pollution % of the sewage, with a higher pollution % having a higher cost to pay. The price at the customs house seems to assume the pollution % for citizens' sewage at 52%, so if you want to estimate what the cost will be to export sewage from an industry, you need to do some math:

Cost = P ÷ 0.52 × V × P%, where:
• Cost = the approximate fee required to export sewage.
• P = Price of waste water listed at the customs house.
• V = Volume of sewage you want to export.
• P% = the pollution % of the sewage you want to export.


In most cases it is (sadly) just fine to just dump sewage untreated to save chemicals and forgo building an expensive treatment plant. The pollution model is very simple in this game, with only the "point source" pollution model covering all aspects of pollution except radiation, so instead of raw sewage spreading throughout and polluting entire bodies of water, you will instead just see a "cloud" of pollution around the discharge point much like with industries.

Pollution affects three things in the game, including from sewage:
• Citizen homes - Citizens who live in a polluted home will lose health, especially with high levels.
• Water sources - Sometimes it is okay to build these in polluted areas, but not often.
• Attractions - Citizens won't care, but pollution will lower the tourist rating of most attractions.

• Citizen exposure to pollution should always be avoided, especially on harder citizen reactions setting, so you should try to dump raw sewage far away from the homes of citizens if you do not treat it first.
  
  
• It can sometimes be okay to source low quality water for industries in polluted areas, but in general water should be sourced from pollution free areas to minimize the chemicals needed to increase the quality level.
  
  
• Tourism scores suffer with sewage dumped nearby hotels, attractions, and shops, so you should try to avoid dumping sewage near any of those, or you will find your tourism rating falling with fewer tourists wanting to enter your republic.

So usually you will simply want to dump your sewage at least a km away, but if you find yourself tight on building space for residences, water sources, and tourism, you might want to treat your sewage then. Normally dumping just 70 m³/day of sewage with a 52% pollution percentage will expose all the land within 700m to severe pollution, but if it is treated, then it becomes barely noticeable.

You might also just treat all sewage for bragging rights.

With the addition of the Biomes DLC, there was a new water mechanic introduced for desert maps.

Desert maps basically have a water table that affects the output of wells and surface inlets much like a resource deposit's "quality" does for its extraction, which the game refers to as "Water amount in area" with an accompanying percentage. This percentage scales the output of wells in the area, which greatly restricts the availability of high quality water on desert maps.

For example, building a well in an area with only 50% "water amount in area" will effectively halve the well's output. Surface inlets are not affected and can be placed on any body of water with full output.

Currently the water table does not seem to change, so you don't need to worry about depleting the water table with too many wells, but farmland and trees also depend on the water table for growth, so you will have to balance out their usage of the water table.

The Early Start DLC adds a couple water management buildings. This section documents their stats and compares them to similar buildings.

The Early Start water well is basically a large base game well, with the following major differences:
• Produces only 180 m³/day of water compared to 215 m³/day.
• Needs less steel for the amount of water it makes. The overall cost of the materials is the same.

There is no Early Start well that doesn't need workers, so you will need to use workers to source high quality water or spend a lot more chemicals and treatment plants to get the quality up. Later on, you can use the Early Start well to save money on steel imports if you can make the other materials yourself. Once you make your own steel, there isn't much reason to build the base game large well unless it isn't available.

Two (three technically) early variants were included for pumps, with the most notable difference being the lower pressure boosts they can create compared to their modern variants:

*Per side, with only one inlet or outlet pipe connected/running.

The Early Start water treatment plant is like the small base game variant but with a few differences:
• Processes up to 240 m³/day of water instead of 120 m³/day (same water per worker ratio though).
• Takes up a lot more space (more than any other water treatment plant.)
• Costs about as much as the base game large water treatment plant.


There currently isn't an early start sewage treatment plant, though that usually isn't a problem.

This section discusses how to design a functioning water and sewage network. Later sections describe how water and sewage components function and how trucks can be used.

The exact mechanics of water pressure and flow can get rather complicated, so I have split up the guide into two parts: one for basic thumb rules a player can follow, which should enable them to build a sufficient, if somewhat overbuilt system, and another part for ways to calculate the expected flow of a design so players can build a very cost efficient system. This part is the simple version.

The water distribution system in the game is a pressure based system; this means that water will flow from one building to the next so long as there is enough pressure across the pipe, which also determines the flow rate through the pipe.

Basic Water Distribution Rules:

• Pressure is gained from pumps and drops in height and is lost when going to higher heights.
  
  
• Pressure is not exerted through buildings, so to maintain flow between buildings, there needs to be either a drop in height or one of the buildings must be a pump. The only exception to this is water switches, whose input pressure will be altered and passed to its outputs.
  
  
• Some buildings store water at heights above or below the ground, which can result in internal drops or gains in height. For example:
  • Water towers store water high above the ground, so they need more pressure to get water into them, but this same pressure is exerted on its outlets.
    
  • Water reservoirs store water below the ground so it takes less pressure to get water into them, but more pressure is needed to pull water out of it.
  
  
• The water stored in buildings will also exert a pressure on its inlet and outlet pipes, with more pressure exerted as the water tank fills. Inlet pipes will lose pressure as the tank fills, while outlet pipes gain pressure.
  
  Generally this behavior can be ignored unless you want to build up a reserve, in which case you can just add more pressure to the inlet pipe with a pump or by raising the source. Exact pressure numbers can be found in the Equations - Water Pressure & Flow section under the Tank Water Pressure and Height heading.
  
  
• Pipe sizes scale the pressure and thus flow gained or lost to a change of height, but do not affect the pressure boost from pumps.

The overall flow of water through a string of buildings will be limited to the pipe with the lowest pressure or building with the lowest flow limit (like treatment plants) through it.

Some basic water distribution numbers and guidelines for planning a basic water system. More in depth mechanics and equations are discussed in a later section for much closer approximations.

These thumb rules are a set of simplified guidelines that were boiled down from the equations and behaviors of the actual system, so you might get more flow than expected, but you should not get less:

• Every Bar of pressure can create up to 24 m³/day of water flow (sometimes more), but this may not be reachable if upstream or downstream bottlenecks exist. Either way, if you divide the flow you want to have by 24, you will get the minimum pressure needed to sustain that flow.
  
  
• Pipes have maximum pressure limits, which will limit the maximum flow of water through them.
  
  
• Every 1 meter change in elevation will add or subtract so much pressure and flow with the following pipe sizes:
  • Small - 0.0126 Bar & 0.3024 m³/day.
  • Medium - 0.0273 Bar & 0.6552 m³/day.
  • Large - 0.0615 Bar & 1.476 m³/day.
  
  
• Each water storage will have an internal change in height that will add or subtract so much pressure (▲P) from its inlets and outlets:
  
  
  Building*

  Inlet ▲P**
  (Sm, Med, Lrg)

  Outlet ▲P**
  (Sm, Med, Lrg)

  Small Water Tower

  -0.378 Bar, -0.819 Bar, -1.845 Bar

  +0.378 Bar, +0.819 Bar, +1.845 Bar

  Big Water Tower

  -0.63 Bar, -1.365 Bar, -3.075 Bar

  +0.63 Bar, +1.365 Bar, +3.075 Bar

  Underground Reservoir

  +0.1764 Bar, +0.3822 Bar, +0.861 Bar

  -0.1764 Bar, -0.3822 Bar, -0.861 Bar

  Small Well

  N/a

  -0.189 Bar, -0.4095 Bar, -0.9225 Bar

  Large Well

  N/a

  -0.1764 Bar, -0.3822 Bar, -0.861 Bar
  *Other buildings have a similar effect, but for this level of planning, it is ignorable.
  **This does not include the pressure from the water in the tank.
  
  
• Pumps create a pressure boost that is applied twice, once to its inlet pipes and once to its outlet pipes. Each pipe on a side will get an equal share of the pressure boost unless that pipe cannot get or doesn't need to move water.
  
  For example, a pump that adds 6 Bar to its inlets and another 6 Bar to its outlets, three inlet pipes would each get 2 Bar added, while two outlet pipes each get 3 Bar added.
  
  
• Water switches obey their own rules and are difficult to estimate the flow for, but generally you can count on them to output an equal or higher pressure than their inlet pressure so long as the inlet and outlet pipes are the same size and the switch connects to buildings at the same or lower elevation.

Start at a building and progress to the next connected building while adding or subtracting the various pressures per the thumb rules to get a rough idea of the pressure and thus flow between the buildings.

Generally you should add them in this order:
• Source Building height effect (if listed above) for connected outlet pipe's size.
• Elevation difference times the pipe's pressure change per meter.
• Destination Building height effect (if listed above) for connected inlet pipe's size.

For example, the pressure for the following pipe connections...

Small Well → (Medium Pipe, + 7m) → Small Pump (Early Start) → (Medium Pipe, +0m) → Big Water Tower.

... would be added up like so:

• Well to pump:
  • Small Well → -0.4095 Bar (internal storage effect on a medium outlet pipe)
    
  • Medium pipe w/ 7m rise → 7m × 0.0273 Bar = -0.1911 Bar (lost due to going uphill)
    
  • Small Pump (Early Start) → +2 Bar from boost (no splitting for one pipe).
  Total Pipe Pressure* = -0.4095 Bar -0.1911 Bar + 2 Bar = 1.3994 Bar
  Total Pipe Flow* = 1.3994 Bar × 24 = 33.59 m³/day
  
  
• Pump to water tower:
  • Small Pump (Early Start) → +2 Bar from boost (no splitting for one pipe).
    
  • Medium Pipe w/ 0m rise/fall → 0 Bar (no elevation change)
    
  • Big Water Tower → -1.365 Bar (internal storage effect on a medium inlet pipe)
  Total Pipe Pressure* = +2 Bar + 0 Bar - 1.365 Bar = 0.635 Bar
  Total Pipe Flow* = 0.635 Bar × 24 = 15.24 m³/day

*You will actually get more pressure and flow than this, but you will not get less.
Making more exact measurements requires a lot more knowledge about the water mechanics.

Also, since the "pump to tower" pipe has more flow/pressure than the "well to pump" pipe does, the flow along the whole system will be limited to the "pump to tower" pipe's flow rate of 15.24 m³/day.

Designing sewage networks is much less complicated than designing water networks, but sewage still has some aspects to consider.

Contrary to popular belief, sewage doesn't require a downhill slope to flow through a pipe; the actual requirement is that the pipe must connect an outlet to an inlet at a lower height or sewage will not flow through it. Like with water, the exact path the pipe takes does not matter; only the endpoints affect flow behavior.

As for placing sewage pipes, the game wants you to place them with a slope and will usually forbid you from dragging pipes from an outlet to a higher point with the error message: "Requires proper slope." This makes it hard to build sewage pipes across depressions or below other underground infrastructure, but there are ways around this (discussed in the next section).

On flat land you will need to use sewage pumps to provide a lower point for building outlets to connect to, but sewage buildings can be built along the slope of a hill to avoid the need for pumps. Stretches of flat land can also be covered by a single pipe segment so long as the pipe is started from a point above where it connects to, though this can sometimes be difficult to place.


Assuming the pipe goes from a higher point to a low enough point, there are only three known limits to sewage flow in the game:
• Pipe flow limits - Pipes can only support so much flow through them a day.
• Treatment plant throughput limits - Only so much sewage can be processed a day.
• Sewage loading/unloading station - Each outlet pipe can support much less flow than usual.

The exact height drop required for a pipe seems to depend on the amount of flow you want through it, but only a 5 meter drop seems sufficient for maximum flow through the largest sewage pipe. Low flow pipes (< 25% of the pipe rating) can make due with almost no drop. You can estimate the drop by comparing the elevations and the inlet/outlet depths of the buildings in question; the inlet/outlet depths can be found in the end of this guide in the Equations - Sewage section, and you can find elevation heights with the Tool for Measurement found in the terrain tools tab on the bottom menu (measure from the center of the building's footprint).

Curiously, sewage tanks will also start backing up and stabilize at some amount of sewage if their outlet pipe's drop isn't quite far enough, and they will even fill up and overflow if the drop is much too short. This implies that the sewage levels of tanks are factored into the drop height calculation of the pipe between them, though like with water, this effect seems to be rather minor.


Unlike water switches, sewage switches don't have any tricks or exploits to overcome the sewage pipe flow limits (that I know of anyway). Just be careful to avoid overloading pipes and don't route sewage mains through a sewage loading/unloading station to avoid reducing the pipe's flow limit (use a switch to connect it into the sewer main pipe instead).

Sewage treatment plant limits are discussed in the Treatment Plants section. To summarize, they can be limited by their workforce, the total amount of flow, or the change in the waste water's pollution percentage.


Pretty much. Sewage flow mechanics are way more simple than the water system mechanics are; so as long as the pipe connects to a low enough place (no more than 5m), sewage will flow up to the flow limit of the pipes and treatment plants.

See the Water Sourcing and Disposal section for the actual challenges associated with sewage, and check out the Planning Water & Sewage Networks section for guidance on planning a sewage network.

One problem with sewage pipes is that it can be difficult, if not impossible, to lay sewage pipes across a body of water or a depression in the ground. This is problematic if you want to connect a small island or the other side of a wide river, bay, or channel to your main sewage network, as the only other options are to build a bridge and have trucks handle the sewage or just build a separate sewage network. This also makes it difficult to thread sewage pipes between the ground and other underground infrastructure like tunnels, power cables, and pipes.

Fortunately, the sewage pipe placement rules can be bent to allow a sewage pipe to slope down below a body of water, a depression, or other underground infrastructure and then flow uphill, much like how a sewage inverted siphon works in real life. For example, in Poland there is a canal named the Adolf Hi- *Cough* the Gleiwitz Canal![en.wikipedia.org] Sorry comrades, I had something in my throat.

Anyway, under this canal runs a sewage line with an inverted siphon (shown in brown), which is what this section will explain how to build:
Picture from comrades Jacek Hulimka and M. Kałuża[www.semanticscholar.org]

Inverted siphons can also be used to follow the terrain closer to the surface because they can go up and down hills without using pumps and instead of being laid deep within the hills. This can be used to reduce digging times and build the pipe sooner, as depth determines the number of workdays required for the pipe's "ground works," but this will require some more prefabs because the path of the pipe is less direct. You will have to weigh the circumstances to determine whether this option is best.


Here a chemical plant dumps sewage on the other side of the bay.

The first step to building inverted siphons is knowing how to bend the sewage pipe placement rules.

The game will usually only allow you to place sewage pipes if the pipe has a downhill or somewhat level slope, but there are two ways to get around this:

• The game does not check the endpoints of any pipe you connect to, so you can simply place two pipes going downhill towards each other and then connect them to each other at the bottom with a third pipe (you may need to drag the connecting pipe from the other pipe if going from the first one doesn't let you).
  
  
• If the endpoints of the pipe segment you want to place will be at similar elevations, then the game will allow you to drag long pipes across water and it will have the pipe follow the terrain under the water.

For the second method, be careful not to place the last endpoint too high above the starting endpoint, or the pipe will end up floating just below the water.
I don't think this impedes ship travel, but I have not tested it.


One requirement that cannot be bent is that sewage will not flow from a building's outlet if the inlet it connects to is above it. The tool for measurement is helpful for checking there is a drop in height from inlet to outlet, but be careful to include the depth the pipes connect at (inlet and outlet heights for buildings are listed in the Equations - Sewage section).

You have two options to make one:

1. Drag two pipes out to the lowest point under the body of water and then connect them at the middle (you will have to lower the end of the pipe to place it underwater; the game wants to put the endpoint at sea level by default).
   
   
2. Drag a pipe across the body of water with its endpoints at about the same elevation.

The second option is faster and it is usually faster to construct because it tends to follow the lay of the land better (less digging for the "ground works" is required), but its main downside is that it is mostly restricted to straight or very gently curving pipes.

Whichever option you choose, the general procedure for placing the inverted siphon looks like this:

1. Open the tool for measurement and place the buildings you want to connect across the body of water (or the valley) such that the building with outgoing sewage has its outlet above the inlet of the building receiving the sewage (if you don't do this, sewage will not flow).
   
2. Determine the endpoints for placing pipes and set a line between them with the tool for measurement (this will help keep all of the pipes inline, especially if you opted for the first method).
   
3. Place the pipes for the inverted siphon by either method:
   • Drag pipes from each building to an area between them while using the tool for measurement line to keep the pipes inline, then connect these pipes with a third pipe to make one pipe.
     
   • Drag a pipe from the low building to a point of similar elevation close to the higher building, then connect this pipe to the high building with another pipe (drag the second pipe from the higher building).
4. Confirm construction, or split up pipe segments first if desired.

You might also want to make a save, enable auto-build, and test to see if the pipe works. If it does, you can just reload the save.

Some things to keep in mind while designing your water and sewage systems.

Pipe segments can only have one excavator working on them at a time, but if you have separate segments for the same length of the pipe, then you can have multiple excavators working on what is effectively the same pipe (you can join them together once they are done). To get multiple segments, place and confirm one segment, and then place and confirm the other one. Don't worry about access; so long as all of the segments are connected to a building, construction offices will be able to access all of them (assuming the normal CO requirements are met).

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Laying pipes close to the surface to reduces digging time, which allows pipes to be built faster, but this may require more steel or prefabs if the pipe's path follows the curve of a hill instead of just cutting straight through it.

To avoid having to recalculate the maximum pressure and flow each time you want to add on to a water or sewage system, you should record the designed pressure and flow of the main sections you build, such as the supply to a town's water tower.

You can maintain a notebook for your system, but I would recommend just renaming the parts of your water and sewage system with the expected pressure and the remaining capacity. For example, a town's water tower could be renamed with a code like: WT-4.5-65% (a water tower with 4.5 Bar of water supply, of which 65% has been reserved for the various buildings it supplies).

If you do choose to record these numbers, remember to update them once you finish designing the new additions to a system.


Citizens will consume far more water and thus create far more sewage when you upgrade their water supply from truck supplied substations. Sewage trucks are unlikely to be able to handle this much higher volume (10 times as much for workers, and 20 times as much for everyone else), so you should always upgrade or fix their sewage system first before the completion of the water system upgrades/repairs or else sewage will likely overflow, pollute your cities, and eventually kill your citizens.

Since water substations only check if they are connected by a pipe to another water building, like a water switch, you can just leave these pipes unbuilt until the sewage system upgrades/repairs are completed.


Many water and sewage buildings require electricity to function, so you may want to design your water and sewage systems to function without power for at least a little while so citizens will still get water and their sewage will not back up too far:

• For drinking water, you can pump water up to a water tower and distribute water from it to substations with nothing but water switches and pipes. Since the water tower creates its own pressure due to height and since water switches don't lose pressure no matter how many branches there are, water will continue to flow without the power on until the water tower is empty.
  
  
• For sewage, the weak links are sewage pumps and sewage treatment plants, which sewage will not flow past without power provided. You can either design a sewage network without pumps or treatment plants (pipes and discharges don't need power), or you should ensure they have a reliable power supply (multiple power supplies are best, but you can at least build a nearby windmill).

Many water and sewage components are flammable, so you should be careful when building them in remote areas to remember to provide them with fire fighting coverage, or you may find your entire water or sewage system disabled due to a destroyed pump or switch. Many electrical distribution buildings are not fireproof either, and since a lot of water and sewage buildings need power to function, you should ensure their electric substations get fire coverage too.

The process for planning adequate, if simple, water and sewage networks is discussed here.

1. Figure out the required flow and quality.
2. Find an adequate source for water.
3. Plan out the local water substations.
4. Plan out the distribution piping.
5. Plan out the sewage network.

Before an adequate system can be designed, the amount of water it needs to handle must be known, so first add up all of the water for each level of quality you plan to provide, or just assign a budget. Citizens will always need high quality water ( ≥ 97%) while most industries do not, so if you want to save chemicals, you should separately track the total flow rates for each quality of water you plan to supply and design separate systems for them.

Industries list the maximum amount of water they use at 100% production in their menu and tool tips, while citizen usage depends on a few factors. Consult the Citizen Water Usage Rates section to determine the expected amount of water citizens will use per building each day. You might also want to leave a margin of flow for expansion later on.

Once you determine the total flows you need for industries and citizens (or you decide on a budget to use), keep track of them to make planning expansions easier. You can also add these flow rates together to determine the size of the sewage network you will need to design too.

If you only need a small amount of water, you might want to just use water and sewage trucks instead to save money.


Once you figure out how much water you need, you will have to decide how and where to produce that water. Drinking water should usually be sourced from wells to limit chemical expenditure on treatment, but industrial water can be sourced from a variety of sources depending on the required quality (possibly right next to them). Consult the Sourcing Water section for more info on what sources can be used for various water qualities.


Next you should place the water substations to cover the entire area, but keep two things in mind:
• Be wary of how much demand you place on a single water substation.
• Buildings prefer to draw water from substations that were placed (not built) first.

While it is possible for a single water substation to supply an entire area with over 100 m³/day of water, this will require the largest pipe size and near maximum pressure, which may require its own large pump to keep up with demand. An alternative is to build more water substations with lower pressure and smaller pipes, but this leads into the next issue...

Since buildings will prefer to draw most of their water from substations that were placed (not built) first, there is a danger where buildings with access to just the first substations are choked out. For this reason, you should place the first few substations in the center of a town or city district so that buildings with access to fewer water substations won't have as much competition for the later water substations (remember that the water substation's range is a box aligned to the f1 grid, with the substation 352m from the corners and 249m from the sides).

A third option is to just build extra water switches so that additional substations can be built and connected as needed, but keep in mind not to exceed the water supply of the source.


Next you need to connect the source to all of these substations, but there are two considerations:
• Building extra pipes and running a lot of pumps is expensive.
• You probably want a local storage for water.

Usually running a single large pipe to the area is the cheapest and fastest option for a given amount of water, while having a bunch of water switches and small pipes is the easiest for connecting all of the water substations. If you know how the water switches work, it is possible to exceed the flow limit of the pipe instead of building a second or third pipe.

To avoid power outages or upstream disruptions from suspending service (like a pump or switch catching fire or a lack of workers/chemicals for treatment plants), you might want to include a local storage building to continue supplying water while you sort out the supply issues. If the storage also has a drop in height (like a water tower or an underground reservoir on a high enough hill do) and you connect it to the substations with nothing but water switches and pipes, then water service will not be interrupted if the power goes out (until it runs out of water).

Water switches are great for local distribution because they can output similar pressures to their inlet pressure without using any power, which means one pump or one drop in height can supply pressure to all of the substations connected to it by switches and pipes.


There are three things to worry about:
• Having a greater capacity than the water usage rates.
• Substation competition.
• Finding a suitable discharge point.

If you kept the water estimates/budget for the water distribution network, then planning a sewage network capable is just a matter of adding the flow capacities of the pipes to a discharge point until you have more capacity than water usage and then adding enough sewage switches to tie in substations. If you didn't, then you should opt for as large a pipe as you think will be needed and include plenty of sewage switches to connect as many substations as you need.

Since sewage substations that are placed first will get the bulk of the sewage generated, other buildings may not have a place to put sewage if they only have access to this substation. For this reason, the first substations in an area should be placed in the center so that buildings towards the outside of the area do not have their only substation overloaded.

The discharge point can be put any where there is water, but shorter distances are typically best to minimize the time and expense of its connecting pipes. Since tourism, water sources, and residences don't do well with pollution, you might have to go further away or treat the sewage.

Currently, there doesn't seem to be any alerts in the game for water shortages or backed up sewage. At best you might get an alert for low citizen health that might be due to a lack of water or due to something else like overflowing sewage, so you should check your residences every now and then to ensure they have water and their sewage is being emptied.

The easiest way to do this seems to be pausing the game, opening the "Resource status" tab, selecting water, going to the end of the list, and from there looking for the first "residential" type in the list from the back. If the first "residential" type entry has about a tenth of their water tank (about a tenth of their maximum daily water usage, as listed in the building menu popup) then you should be good. If you find one with less than 0.10 tons, you might want to look at it.

Do the same for sewage, but start from the front of the list and look at any building with more than 0.50 tons of sewage. Larger buildings can have more without issue, but generally more than 1 ton can be an issue.

Pollution monitoring stations can also be set to give an alarm if pollution exceeds a set level, so you could have them in your cities to detect overflows of sewage (or garbage) too. I recommend setting maximum pollution to 100% and average pollution to ~5% for the alarm.

The "Resource Status" tab is not foolproof though, so consider doing a quick sweep with the "Water flow" and "Sewage flow" overlays is a good idea to find any bottlenecks or under performing treatment plants. Remember that red is bad for flow but good for pressure, and that you need to let the game run for these overlays' colors to update.

Sometimes you may wonder what size a pipe is (it isn't displayed) or you might be looking for a pipe disconnect; this section discusses how to find both.

I can't believe I forgot this, but the game has a pipette/pick-me tool that selects for placement whatever you click on, including pipes. You can find this tool in the "terrain tools" section on the right side of the bottom menu bar.

To determine a pipe's size, you simply click with the cursor snapped to the pipe (you may need to mouse over the ground directly above the pipe to get it to snap), and then go to the water/sewage section of the bottom menu to see what pipe size was selected.

If the pipette tool isn't an option for whatever reason, then there's really only two ways to check:
• Look at the pressure.
• Try to connect various pipe sizes to the pipe.

Since pipes have pressure limits, you can typically just look at the gauge for the pipe and infer the size from the reading. Small pipes are limited to 1.09 Bar, so any pressure above that is a good indication that the pipe is at least a medium size; and if the pressure is above 2.36 Bar, then the pipe is a large pipe. If you see the gauge pegged at these numbers but you know more pressure is available than that, then that is also a good indication that the pipe is that size.

Switches may invalidate this test though, as they can exceed the pressure limit of a pipe in some circumstances. Flow is also a less reliable metric, as it relies on more factors than pressure does.


The other, more precise method is to disable the snap (f4) feature and select each size of pipe and mouse over the end of the pipe in question. Unlike electric wires, you can only connect pipes of the same size together, so if the pipe you have selected to place is the same size as the pipe in the ground, your mouse cursor should snap to the endpoint if it is close enough. If the sizes differ, then the mouse cursor shouldn't snap to the pipe's endpoint.

Unfortunately, since this method requires the pipe's endpoint to be unconnected to check, you will have to delete a portion of the pipe to create the endpoint (I recommend making a save first comrade).


Sometimes you may fumble your clicks and fail to connect two buildings together, but the pipe break will not be emphasized. Fortunately, there are some tools that can be used to make finding it easier.

There are two type of breaks to look for:
• Pipe to pipe, where pipes did not connect to each other.
• Pipe to building, where the pipe doesn't connect to the building.

Procedure:

1. For both breaks, you should start by enabling the snap (f4) feature and then selecting any water pipe (or if checking for a sewage pipe break, select a sewage pipe).
   
   
2. Pipe to building breaks are the easiest to check for; simply look at the buildings the pipes are supposed to connect to and look for the building's connection point icons. If a pipe is connected to one of them, then the icon for that connection point will not show up, so if you see an icon where you think the pipe should be connected, then the break is there.
   
   
3. Pipe to Pipe breaks are a little harder to look for; you need to check the ends of a pipe segment to see if it is actually connected to another pipe or not. With the snap feature enabled though, you can highlight entire pipe segments by selecting a pipe and mousing near it. With the entire pipe highlighted, check each end to see if it is connected or not.
   
   
4. If you want to confirm this is the break, try to connect the three pipe sizes to it. If the end point really is a break, your mouse cursor should snap to it with a the same size pipe selected, but if there is an open connection point at a building nearby, the mouse will prefer to snap to that though.

This section discusses mechanics of the water distribution components that do not relate to the flow or pressure going through them. If certain components seem rather lacking in their description, it is because they are explained in a lot more detail later on or are really just that basic.

For info on how to estimate the flow of water or the pressure in a water system, see the Water Distribution 101 section, or if you want more exact methods to estimate water flow and pressure, see the Advanced Water Distribution section.

Any building that handles water or sewage will have a storage for them, even switches and unloading & loading stations.

Most buildings with a water tank and a sewage tank have the option to drain their water into their sewage tank, but factories with separate tanks for industrial water and sewage and its workers' water and sewage will always drain water into its industrial tank instead of its citizen's sewage tank.

It seems that most buildings that interact with water will have a water tank and a sewage tank that can store one day's worth of water at maximum consumption, so the "max daily water consumption" rating of an apartment or factory is also the size of its drinking water tank and the size of its citizen's sewage tank. If their water supply is not "pressurized," then buildings can store 10 days of water/sewage for workers and 20 days of water for everyone else.

Typically a pressurized water substation will only fill a building's water tank to 10%, while trucks and unpressurized water substations will typically fill buildings to 100%. Trucks in a technical office will only go to fill water substations while they are less than 30% full.

Water and sewage infrastructure have predefined capacities like factories or transportation infrastructure typically do.

Some industries use water for production and create sewage as a byproduct; both of which may be stored in tanks separate from the worker's drinking water and sewage if the water needed for industry requires a much lower quality than the worker's drinking water. There are two main mechanics affected by this:

• Water/sewage trucks can usually only access one tank, and will ignore the other.
  (See the Truck Mechanics section for more info on this.)
  
• Industrial water and sewage have to be handled by piped connections, while drinking water and worker sewage will be handled by substations.

A few industries use high quality water for their industrial production but do not have separate tanks for drinking water & worker sewage and industrial water & sewage. These factories' industrial water and drinking water are all supplied water by substations and have their sewage collected by substation too.

Pipes are used to connect buildings so water can flow between them.

• Different pipe sizes cannot be connected to each other. This is nice for identifying the size of an unfinished pipe and for avoiding wasting a larger pipe's capacity.
  
  
• Pipe segments can only be built out to 5,603 meters away as the 'crow flies' or the 'air distance' measured by the "Tool for measurement." The actual pipe length may be longer than 5,603 meters due to sloping up or down along this horizontal 'air distance.'
  
  You can still build stretches of piping longer than 5,603 meters, but the pipe will have to be made up of multiple segments, with each being constructed separately.
  
  
• Pipes can normally only be built underground, but terraforming can expose them above the ground and rarely buggy placement will place them above the ground. Typically this will be the reason why you'll get the error "Can't build building due to infrastructure" when trying to build near pipes (or other underground infrastructure).
  
  Telling whether pipes are above ground can be difficult as they are only rendered with the underground (F3) view on and then you need to manipulate the camera so that they are rendered on top of the sky or a building, like so:
  
  

  
  
  If you enable cheats and hold B and the middle mouse button down, you can use the camera panning keys (WASD) to move the camera closer to the ground (or into it) for a better view.
  
  Pipes seem to have a higher change to ignore terrain and be built above it when clicking and dragging a pipe from one building directly to another; placing them in at least two segments seems to prevent this. If you do try to connect two distant points with one segment, you should check to ensure it is actually underground.

Water substations provide the link between most buildings and the water network.

Water substations hold 20 m³ that can be distributed to all buildings within range.
Buildings typically withdraw water from substations until their tanks are at least 10% full.
Connecting a water substation to any water infrastructure with a pipe will result in the substation being counted as "pressurized," where citizens will consume 10 or 20 times as much water. This happens even if there is no water in the substation.

The range a substation covers is a 498m × 498m box aligned to the f1 grid, with the substation at the center, 249m from the sides, and 352m from the corners:

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All substations in the game seem to be like this, but the range can vary.

There is a final pressure drop or gain from water substations to the buildings they supply that depends on the difference in height from the substation and building.

Since most vanilla buildings cannot draw more than ~10 m³/day from a water substation, this rarely matters except in extreme cases (usually a small pipe is required to get pressure this low):

Here a distillery needs about 15.5 m³ of water per day, but it can only get about 12.44 m³/day due to the pressure drop.

A building that is at a higher elevation than the substation it draws water from will have a different pressure and thus flow than said substation. This effect can be estimated by the equation:
Pb = Ps - (▲h × k × 0.1147), where:
• Pb = Pressure at the building.
• Ps = the inlet pressure of the substation.
• ▲h = the elevation of the building minus the elevation of the substation.
• k = the pipe constant (explained in later sections).

If you have the Ukraine DLC, the Dnipro flats can theoretically reach ~26.70 m³/day, but this is unlikely due to how citizen water consumption at home works.

If you use a mod (like very large, 800+ flat apartments) that can draw a lot of water from substations, you might have issues meeting the required flow if the building is high above the water substation and you are using a small pipe to supply the substation.

Various parts of the water distribution system are briefly discussed here. More notable aspects associated with these components are discussed in other sections.

The game has three buildings for storing water: a 70 m³ small water tower, a 300 m³ big water tower, and a 500 m³ ground reservoir. The main uses of these water storage buildings are to act as a buffer to smooth out spikes in demand or to act as a reserve of water in case of supply issues or power failures. They are also useful for combining multiple sources into one pipe.

Depending on whether the water is stored above or below the ground, pressure will be added or subtracted from the inlets and outlets. If stored above ground, extra pressure will be needed to get water into the storage but pressure will be applied to the outlet. If stored below ground, pipes connecting to the inlet will gain pressure, but extra pressure will be needed to withdraw water from the storage.

There is also an option in the menus of these water storages to "shut valves" to stop all water flowing out, which can be useful if you need to purge a network of lower quality water, but generally you won't need to use it.


Pumps are needed to get water out of wells, reservoirs, and treatment plants and up hills or into water towers. The game gives you two to work with:
• Modern Small pump - Can add 6 Bar of pressure to pipes.
• Modern Large pump - Can add 12 Bar to pipes (connecting more pipes reduces the boost).
The Early Start DLC also has weaker variants of these pumps.

Generally you should always build the large pump unless you know what you are doing, as the extra cost is not that much. You might get a lot more pressure/flow than needed, but there isn't really any reason to build the smaller one except to save a little money.

If you want to disable a pump for any reason, you can turn it off in its menu.

For more information on how pumps work, consult the Water and Sewage Networks 101 section or the Mechanics - Pumps section.


Water switches are a building that splits one pipe into three and are useful for distributing water from a single source to multiple destinations. Unlike most buildings, water switches look at their input pressure to determine their output pressure, so you can effectively create pressure once with a pump or a water tower and then use water switches to apply a similar pressure to each destination. Just be careful not to exceed the flow limit of the inlet pipe.

They have a few more quirks that can be read about in the Water and Sewage Networks 101 or the Mechanics - Water Switches sections.


These stations are basically cargo stations for water trucks, which can serve as closer sources of water for technical offices or lines. This is also one of the few ways for trucks to put water into a storage or into a water distribution system.

These stations can be useful in a couple ways:

• You can use a truck on a line to stockpile water for a technical office to use (connect an inlet and an outlet of a water station to a tower and designate the station as a source for the technical office).
  This can be a cheap way to keep water supplied in winter over a long distance.
  
  
• Since water trucks on a line cannot supply drinking water to industries with separate tanks for industrial water, you can connect a water station to a water substation to provide them with drinking water. This will only suffice for understaffed factories though, as the water substation will be counted as "pressurized" and so workers will consume water at a higher rate that trucks may not be able to handle.

See the Truck Mechanics section for more information on how trucks handle water.

Buildings will automatically dump their sewage into sewage substations until they fill up. Like water stations, the first ones placed will be utilized by all buildings in range first. If a substation fills up and cannot get rid of its sewage fast enough, then buildings will send any remaining sewage to other sewage substations within range. If there are no empty substations, buildings will just dump their excess sewage, which creates a lot of pollution.

Sewage substations can collect from all buildings in a box aligned to the f1 wireframe, with the sides 249m and the corners 353m from the sewage substation.

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Sewage loading/unloading stations will limit the amount of sewage that can flow through them to 15 m³/day per connected pipe. If you want to tie in a sewage loading/unloading station and not limit your sewage system to only 15 or 30 m³/day, then you should just connect it into the main sewage pipe with a sewage switch instead of routing the sewage line through it.

How and why to use trucks for handling water and sewage are discussed here.

Trucks are another option for automatically delivering water and removing sewage from buildings, but they are generally inferior to a pipe network except in two ways:
• Trucks are far cheaper to set up.
• A truck system can be set up almost instantly, while water systems are rather slow to build.

The main downsides are that:
• Trucks generate extra road traffic, possibly at the customs house.
• Trucks have ongoing costs like fuel and repairs; a pipe network does too, but much less so.
• Trucks will struggle to supply the water needed for industrial processes.

There are a few situations where trucks compare favorably to a pipe network:
• Cheaply providing service to remote workplaces (woodcutting posts, large wells, mines, etc.)
• For providing a water of differing quality instead of building a redundant pipe network.
• Saving time on getting towns and industries up and running.
• Saving money on expensive sewage pipes connecting areas far from bodies of water.

Trucks can also serve as a backup to water and sewage systems, or to cover a small shortage of water or overflow of sewage.

In 1960, it costs about ten thousand rubles per km for the steel and prefabs needed for a pair of small water and sewer pipes, while a pair of the cheapest water and sewage V3S trucks only cost about 7,200 rubles. If you have small workplaces even a few km from a water/sewage network, you can save a lot of money by using trucks instead of extending the pipe networks.

Another case for saving money is with industries requiring their own quality of water. To save chemicals, you could make two water systems for supplying high quality drinking water and low quality industrial water, or you could supply drinking water by truck and build only one water network for industrial water usage.

For example, a concrete plant needs 55% quality water for making concrete while its workers need high quality drinking water. You could build it its own surface pipe with a small pump and pipes to supply industrial water, and then provide drinking water and sewage removal with a truck from a free technical office. This would eliminate building it a separate pipe connection or water treatment plant for drinking water and thus save a bunch of money. You could also build this concrete plant pretty far from your existing water/sewage network, such as in a new area you plan to expand into.

The sooner you can bring a town or facility online, the sooner you can start using it. Since building an entire water network can take quite a while and occupy your construction equipment and workers for some time, you may want to simply forgo building it and instead just instantly buy a couple water and sewage trucks to handle everything.

Later on as the town expands or traffic gets a bit congested, you can always upgrade to a piped network. For a starter town, this will also save you the cost of workers and possibly also gravel and boards if you have set those industries up.

Starting with truck services is also a good way to save money in the early game, as even if you have to pay for water and sewage and the fuel to move them, it will still take a couple years to reach the cost that a piped water system will cost to install with foreign labor and materials.

There are also maps with areas that are both far away from bodies of water and somewhat high in elevation, such as the Slovakia map. Since sewage discharge points can only be placed on the shore of a body of water, your options for providing sewage service to these areas are to either use trucks or build a really expensive sewage pipe from the area to the body of water.

A sewage truck can handle lower volumes of sewage far more cheaply than the pipe, but you will need a big sewer pipe if you continue to develop the area or if you want certain industries that create a lot of sewage.

There are also mods that can dump sewage on land, so if you don't care for this challenge or don't have the skill to handle it, you can use those mods.

The following are basic limitations for water/sewage trucks that occur regardless of whether they are used in a line/schedule or technical office:

• Water and sewage trucks can only be used in technical offices and on lines; they cannot be used in distribution offices (you cannot even send them there).
  
  
• Sewage cannot be imported in exchange for payment; you can still set up a line to import it, but trucks will never load it. (The ability to import sewage was removed in update 0.8.8.14.)
  On some versions sewage can be imported; you'll just have to check.
  
  
• Water may still be exported; however, you won't get close to the listed price for water without increasing the quality to 99%. Even quarried stone is worth more than 93% quality water.
  
  
• Water and sewage trucks can unload without any power, but water trucks will do so very slowly.
  
  
• Water and sewage cannot be pulled or pushed across connections by trucks; they must be loaded or unloaded at the same building that the water or sewage storage is in (you still can have pumps pushing water into the storage though, but this may not work with technical offices for reasons listed below).

Water trucks can load water from any water facility with a road connection, including wells, treatment plants, and the water stations. They can also load water from a custom house.

Sewage trucks can unload sewage only at customs houses, sewage treatment plants, and sewage stations. They unfortunately cannot unload at discharge points.

Trucks on a line (a.k.a. a schedule) can also be used to handle water and sewage for certain buildings.

Setting up a line for water trucks is done exactly the same as for every other truck; simply select a water truck in a depot and assign stops to its line.


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Trucks on a Line come with a few restrictions to plan around:

• Trucks on a line can deliver water to, or remove sewage from, only the buildings with a road connection (they cannot use footpaths).
  • This requirement excludes water and sewage substations unfortunately.
    You will have to use a technical office to fill/empty these, or use an unloading/loading station connected to them (this will increase the usage rate of drinking water though).
  
  
• Trucks on a line will not unload drinking water into, or remove the workers' sewage from, any industry with separate tanks for drinking water and industrial sewage.
  • This means all industries that use low quality water for industry cannot get drinking water delivered by a line or have their workers' sewage removed by a line.
    
  • Other industries can have drinking water delivered and worker sewage removed by trucks on a line.
  
  
• Due to the 25 stop limit that Lines / Schedules have, a maximum of 24 buildings can be serviced per truck (one stop is needed to load water or unload sewage).
  
  
• Sometimes the water usage at a building will be enough to make a truck wait until it is completely unloaded rather than just topping off the tank and leaving. If you don't want this behavior, the only fix is to change the amount unloaded to a partial load via the "On this station unload: x%" mechanic.
  
  
• Unlike all other cargo road vehicles in the game, water/sewage trucks cannot have bus end stations in their lines/schedules.

Some ways to make water truck lines more useful:

• A mechanic of all road vehicles is that they will skip stops that are set to only unload when they do not have any cargo or riders. This can be used to make water trucks skip stops if they run out of water instead of wasting time and fuel going to them anyway.
  
  
• Trucks on a line cannot handle the water or sewage for workers in industries that use low quality water for industry, but they can unload into a water station or load from a sewage station and let either a small local pipe network distribute this water and collect the sewage or let a local technical office handle it.
  
  Basically you can have trucks on a line make the long distance hauls with full loads and have them wait at the stations for the local network or technical office to empty or fill them.
  
  
• To limit the waste of fuel, you can tell trucks to "wait until unloaded" at the stop with the highest water usage rate. Since all buildings have the same number of days in water storage (assuming they are all "unpressurized" or "pressurized"), the truck should leave to get more water or empty its sewage before the other buildings run out of water or fill up with sewage.

Water and sewage trucks can work in a technical office to automatically service the buildings in an area when they need their water refilled or their sewage tank emptied.


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Setting up a technical office to handle water and sewage is quite easy:
• Build a technical office and open its menu.
• Set its working range (1 km, 2 km, 3 km, 3.5 km, or some value between 100m and 3.5 km).
• Use the "Specify or replace a source building" to set the water source
• Use the "Specify or replace a source building" to set the sewage unloading building, if needed.
• Move a water and sewage truck into the technical office.

There are four vanilla technical offices in the game. You can select a technical office to build from the "Maintenance" section of either the "State Infrastructure" tab or the "Roads / Vehicles" tab within the construction menu.

Once you set up a technical office for water and sewage, trucks will automatically service the buildings in its area.

Water Service Calls:

• Buildings will "put out a call" for water service when their water tank falls below about 30% full.
  
• A water truck will then go to the assigned water source and fill its onboard tank completely (even if it already has enough water), and then go to refill the building's tank.
  
• Water trucks will unload water until the building's tank is full or the truck runs out of water.
  
• Once the building's tank is refilled above 30% full, it will stop putting out a call for water.

If another building has put out a call for water service before the truck returns to the technical office, this truck will be reassigned to it and immediately go there so long as the truck still has water in its tank; if the truck is empty, it will first go refill at the water source before going to the building.

Water trucks working for a technical office will always fill completely up with water, even if the building they are fetching it for cannot hold it all. This can save a trip to the water source if they get a new call before they return to the technical office, but once they return to the technical office, they will always go to the source first, regardless of their current amount of water.

Usually only one water truck will be assigned to a building at any one time, including during the return to the technical office. This is the main reason you should not try to supply industries with water for their production (drinking water for workers is another matter though).

Sewage Service Calls:

• Buildings will put out a call for sewage service when their sewage tank fills above ~70% full.
  
• A sewage truck will then go to the building and empty the building's sewage tank until it is empty or the truck is full.
  
• The truck will then go to the set sewage unloading building and unload all of its sewage.
  
• Once the building's tank is less than 70% full, it will stop putting out a call for sewage service.

If another building has put out a call for sewage service, this truck will be assigned to it and immediately go there to empty the building's sewage tank so long as it isn't full. If it is full, the truck will not be assigned until it empties its tank.

Technical offices must work under some limitations:

• Max Range of 3.5 km - The technical office can only service buildings up to 3.5 km away from the building as measured along the road from the technical office's entrance. You also have to enable this range in its menu; 1 km is the default range.
  
  If you mouse over the technical office's menu, it will highlight the roads it can reach in yellow and the buildings it can service in green (new buildings may need a moment to be recognized). Keep in mind that certain buildings like end stations and bus stations do not allow road traffic to pass through them without making a stop there, which will prevent technical offices from servicing buildings on the other side of these stations (as seen below).
  
  You can source water from, or take sewage to, an unlimited distance away from the technical office, but it is typically better not to make vehicles in a technical office travel more than 3 to 5 km to get water or to unload sewage. If you have to though, it is best to get trucks with a large capacity.
  
  
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  You can use a free technical office to quickly see if a building will be highlighted green and thus in range of a larger technical office, just remember to make the road to the entrance a little shorter to guarantee its reach doesn't change.
  
  
• Not Meant for Industry - Technical offices can only fill the drinking water tanks of factories and will completely ignore water tanks that are used exclusively for industrial processes; likewise, technical offices will only empty the sewage tanks that the factory's workers fill while ignoring the sewage tanks that industrial sewage fills.
  
  The exception to this rule is factories that do not separate the water and sewage of the industry and its workers (i.e. the food factory, distillery, and livestock farm). A technical office can directly handle the industrial water and sewage of these factories, but it is not recommended for a few reasons:
  • The technical office will often not send more than one water truck to refill the same water tank, and since water trucks are not dispatched until the water level is around 25% to 30%, and since these factories all use 10 or more cubic meters of water a day, most of these factories will likely run out of water long before the truck can get back from a water source not even 500m away.
    
  • The technical office also does not like to send out more than one truck at a time for the same building, so these factories will usually be limited to the throughput of one truck, which will not be enough even with the water source quite close (< 500m).
    
  • Sewage is handled a little better, but can still be quite unreliable, even with the sewage unloading source nearby.
  
  Basically you should never rely on a technical office to handle the industrial water or sewage needs of a factory; they just do not have enough throughput or reliability to do it, so use trucks on lines instead.
  
  Technical offices can handle the drinking water and the workers' sewage of industries though.
  
  
• No Backup Buildings - Technical offices can only load water from one building and can only unload sewage to one building, so you need to ensure these buildings are always working and accessible or the technical office will not be able to handle the water and sewage of an area.
  
  
• Cannot Serve Unloading and Loading Stations - Technical offices will not service these buildings, so do not plan on supplying a water network from, or emptying a sewage network at, these buildings with a technical office.
  
  You can still use these as "sources" for the technical office, where it can get water and dump sewage at.

Technical offices and lines are both options to handle water and sewage for buildings, but they are not equally suited for all situations.

Lines are best for saving money/resources on providing water/sewage service to small groups of remote buildings or for supplying industries with moderate amounts of industrial water.

Lines are not very good for providing a lot of buildings in an area with water or sewage service and cannot access buildings through footpaths. They also cannot handle the water and sewage for workers at industries with separate tanks for the water/sewage of workers and industrial processes, or at least not without extra water/sewage infrastructure.


Advantages:

• No building required → Cheap and fast to set up.
  
• Can provide all industries with water for industry.
  
• Not limited to the technical office's 3 km range → No range limitations.
  
• You can use line spacing for better delivery frequencies.
  
• Doesn't wait for buildings to need service → Always running → Higher throughput per truck without buildings being chronically low on water or full of sewage.

Disadvantages:

• Cannot use footpaths → Cannot refill or empty substations directly.
  
• Can only service buildings with a road connection → Some buildings are inaccessible.
  
• All buildings have to be on the line → Not suited for a lot of buildings.

Considerations:

• Trucks on a line can be told to wait until unloaded or loaded at a building to prevent the waste of fuel, but this may not always be feasible, either because parking spots at buildings are needed for other vehicles (including keeping spots open for fire trucks and police vehicles) or because buildings may run out of water or fill their sewage tank while the truck is waiting at another building.

Some disadvantages can be mitigated. For example:

• A cheap and small local sewage network can collect all the sewage in a small area and send it to a sewage un/loading station for trucks to collect at. Water for industrial processes can mostly be done in a similar way, but drinking water will have to be delivered to each individual building because unloading at a water unloading station would result in higher water usage (the substation would be "pressurized").
  
  
• Water trucks can skip later stops in their line if they do not have any remaining water, but only if those stops are set to only "unload" and nothing else (no load and unload or 'nothing'.) You might use a smaller truck to make the skips happen sooner too.
  
  
• Water and sewage trucks cannot use bus end-stations, but line spacing is still an available option for maintaining service frequency. "Wait until loaded" (sewage) and "wait until unloaded" (water) can be used for minimizing traffic and saving fuel too. Because each building has one day of storage for water and sewage, you should make trucks wait at buildings with the most regular usage; typically this will be workplaces with the most consistently full staffing, then hotels, and then residences.

Technical offices are best used to handle the water and sewage needs of a somewhat compact area, like a town or an industrial zone, especially since they can access water and sewage substations to cover multiple buildings per trip.

Technical offices are not suited for supplying water for industrial processes, if they are even allowed to try in the first place; they will struggle to keep up with even moderate usage rates. Technical offices are also not suited for long range deliveries of water due to their short range, as their water trucks will always go to pick up water at their source, even if they have a nearly full tank already, and buildings will only call for water when under 30% full.

Advantages:

• Only goes to the buildings that need service.
  
• Doesn't waste fuel going to buildings that don't need service.
  
• Responds to extra calls while out → Minimizes distance driven and fuel used per trip.
  
• Can access substations via footpaths → Can concentrate many service calls into one.
  
• Can access buildings via footpaths → Can service all buildings, including apartments without road connections.

Disadvantages:

• Needs a building → Has extra cost and time to set up.
  
• Demand may synchronize or spike → May need extra trucks to guarantee service.
  
• Limited to servicing buildings within 3.5 km, as measured along the road.
  
• Cannot handle industrial water/sewage unless the industry doesn't keep separate tanks for citizen and industrial water/sewage.
  
• Cannot be used to empty sewage from sewage stations.
  
• Cannot be used to pump water into water stations.

Since technical offices can use water stations as a source of water and sewage stations as a sink for sewage, you could have trucks on a line handle the long distance hauling to/from the stations and let the technical office handle the local distribution.

This section describes how water might be moved by vehicles other than trucks.

There are files for water and sewage wagons in the game (along with other vehicles) but they were disabled by tags in their script.ini files in the v0.8.8.9 update, as they had been added by mistake (according to the developers). Likely they didn't want you to be able to export water in bulk for a lot of easy money.

Enabling them is rather easy, but you will have to get a mod for a water loading train station, as there is no way to fill water wagons in trains in vanilla (technically there are vanilla stations in the game that are also disabled, but they cannot be so easily re-enabled).

There are no ships nor aircraft in vanilla that can handle water, but now that we can move used vehicles as a cargo, you can use certain ships and cargo helicopters to ferry water and sewage trucks to islands or remote areas without a road. The Ukraine DLC also adds a cargo plane that can carry vehicles, but it comes rather later in the game.


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This "ferry" concept is explained here; just substitute water or sewage in the place of fuel.

Technically you can "ferry" trucks with trains too, but since trains are on land, just sending water and sewage trucks via a road is usually a much easier option.

This section describes the various gauges, meters, tank volumes, etc. used to show various stats of water and sewage.

Each building that handles water is provided with a set of gauges and meters for displaying pressure and flow information for water.

Sewage doesn't get any gauges or meters because it would have the same flow as the water gauge/meter at the building it is made at. For sewage collection systems, you can enable the "Sewage flow" overlay to view the flow through sewage switches, pumps, and discharges.

There are two types of gauges/meters for water: Pressure and flow.


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You can minimize the gauges/meters section to get a simple decimal readout of each gauge too:

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Since pressure is required to move water and can be usually be used to easily find the maximum amount of flow that can be supported, knowing how to read its gauges and meters is quite useful.

Every building that handles water will have a separate gauge/meter for each of its inlets and outlets. Most of these buildings only have an inlet gauge/meter, but vanilla water buildings can have up to six pressure gauges/meters. These gauges are labeled as "Input #" or "Output #," which correspond to their respective inlets or outlets, but this will rarely be useful, as you'll probably have no idea what pipes these are referring to with just that.

Fortunately, you can mouse over a gauge and the game will highlight the connected pipe segment in green (as is seen in the above screenshot). Unfortunately, only the closest pipe segment gets highlighted, which can make it difficult to trace the pipe out to distant areas or within clusters of other pipes (as is also seen in the above screenshot).

As of v0.9.0.4, you can now use the "Connect two pieces" tool found in the terrain tools section to join pipe segments together.

Pressure gauges display the difference in pressure from the source's tank to the destination's tank, but only within the range of 0 Bar to 6 Bar. The inlet gauge of a destination building should read the same as the respective outlet gauge of its source building.

If you mouse over a gauge, the game will also show the actual pressure as a decimal (if above zero Bar). The pipe connecting two buildings can be made up of any number of pipe segments and the pressure reading of the gauge will be unaffected.

When mousing over the gauge of a piece of water infrastructure, you may also get the indication: "Max flow at max pressure per day:" This seems to be intended as an aid for the player to gauge whether a pipe has the required flow/pressure potential for the player's needs, but unfortunately this appears to be inaccurate and thus should always be ignored.


Pressure gauges have a couple interesting behaviors:

• Pressure gauges/meters will only display a pressure if the source building has water in it, regardless of whether its valves are shut or if the destination building has any water in it.
  
  Switches, as usual, are the exception and can transmit pressure to their destinations without having any water within themselves, but their readings will be about 0.08 Bar above what the actual pressure will be with flow.
  
  
• Output gauges may only appear if their respective outlet is connected to another building with a pipe, while input gauges for inlets are always shown.

Each building that handles water has one flow gauge/meter that shows the combined rate of all the water that either:
• Left the building to flow into another building,
• Was consumed by citizens or livestock, or
• Was flushed from the drinking water tank of a building.

Water consumed by industrial processes will not show up in the factory's flow gauge nor in the factory's "Water flow" overlay indication, but all the water flowing into the factory will show up in the gauges and overlay indications of the buildings that it flowed from, such as switches, water storage buildings, and pumps.

Flow gauges have a range of 0 to ~127 m­³/day, but the decimal readout below it has no upper limit. Negative flow is not possible (all water pipes are one-way), so negative numbers are not depicted.

The current water usage rate for industrial processes in a factory can be easily determined by multiplying the factory's "Current production percentage" by the amount of water listed under its "Consumption at maximum production:" heading. For example, a chemical plant operating at 50% production will consume 50% of its maximum consumption rate of 10 m³/day of water, for a current consumption rate of 5 m³/day of water.


Flow gauges also have a meter on them that records the total amount of water that has flowed through it since the save was loaded or from the last time it was reset (by clicking on it), again excluding the water that was used within the building for industrial processes.

If you want a more permanent record of the amount of water usage in an area, you will need a city-hall/accounting-office.

You can open a building's menu to see the current volume of water and sewage is in its tanks, as well as the associated quality or pollution percentage.

If you open the menu of a building, water and sewage tanks will be displayed in one of two ways:

1. One pair of water/sewage tanks will be always be shown as a water flask and a "manhole."
   • Tanks for the drinking water and sewage from citizens are always prioritized for this method.
     
   • If a building only has one water/sewage tank, then that tank will be displayed with a flask or manhole.
     
   • Sometimes the tank will also be displayed like any storage for a good is.
2. Any remaining tanks will be displayed like any other goods storage with the names:
   • "Water tank (import)" or "Water tank (export)."
     
   • "Sewage tank (import)" or "Sewage tank (export)."

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Water quality and sewage pollution percentage are also displayed, but you will have to mouse over the flask or manhole for their respective tank volume/quality to be shown.

Next to each tank listing or flask may be an icon of a water faucet. This is a "button" that if pressed, will drain water from the tank into a sewage tank.

If the building has a tank for industrial sewage, then all flushed water will drain to this tank, even the water from drinking water tanks. If no industrial sewage tank exists, then all water will drain to the citizen sewage tank.

The main use of this function is to get low quality water out of tanks that need higher quality water, but you shouldn't need to do this often.

When you open the menu of an industry you can also find the required quality and volume of water required, but you can see this information before building it by looking at its popup card in the construction tab.

Enabling cheats will result in extra information being displayed in a building's menu:
• Hidden water tanks will be shown (usually) as normal storages.
• You can mouse over the water flask for an exact reading of the amount of water in it.
• You can press Ctrl - B to show the components of the water and sewage tanks.

If you have cheats enabled, then mousing over the water flask will also display the percentage that the flask is filled to, but instead of saying "water filling:" it will be listed as "sewage filling."

Ctrl - B will show the components of water and sewage, but this is usually not that useful:

The game offers you quite a few overlays to keep track of your water and sewage systems, vehicles, and buildings; as well as the pressure and flow between them.

There is an option at the top of the overlay tab to keep the overlay on without the overlay tab open, and below that there is another option to select the range you want the overlay to cover, from 1 km to 3 km.

These overlays are useful for confirming at a glance that various buildings have access to water or sewage substations.

"Water"
→ Found under "Building network connections"

This overlay displays an icon over all water substations within range, and highlights buildings that need water in green if they are within range of a water substation. Buildings that are in range of multiple substations are highlighted in darker shades of green:

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"Sewage"
→ Found under "Building network connections"

This overlay displays an icon over all sewage substations within range, and highlights buildings that need sewage service in green if they are within range of a sewage substation. Buildings that are in range of more substations are highlighted in darker shades of green:

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These overlays show how much water or sewage is within the water/sewage infrastructure and vehicles. Confusingly, the pure water component of sewage is shown as water in vehicles, and the pollutants component of water is also shown in vehicles.

"Water"
This overlay shows how much water is within water towers, water reservoirs, and water substations, which makes it a decent way to quickly check if the storage buildings in an area are running low on water.

Unfortunately, empty buildings do not display a zero (though almost empty buildings do), so completely empty water substations and water storages will not be shown.

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"Waste Water"
This overlay shows how much sewage is within sewage switches and sewage substations, which makes it a good way to quickly check if a sewage network is overflowing:
• Sewage substations should have less than 12 tons of sewage.
• Sewage switches and pumps should have less than 1.0 ton of sewage.
• Sewage discharges should be nearly empty.

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This overlay will display a generic vehicle icon over each vehicle of the selected type within a selected distance. There are only two water and sewage vehicles to select:
→ Water cistern
→ Sewage cistern

This overlay is mostly useful for watching all of the selected vehicles moving about an area or on a line, typically to ensure adequate spacing between them or that they aren't stuck at one spot.

"Water cistern"

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"Sewage cistern"

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These overlays can be used to display an icon over all the buildings of the selected type, within the selected distance. There are nine categories that water and sewage buildings can be under:
→ "Water well" (this includes the surface inlet pipe)
→ "Water facility" (general water infrastructure, like switches, water towers, and pumps)
→ "Water treatment"
→ "Water substation"

→ "Sewage discharge"
→ "Sewage facility" (switches and lift pumps)
→ "Sewage treatment"
→ "Sewage substation"

→ "Cargo station" (For finding water/sewage loading & unloading stations.)

You can use this to quickly show all the buildings in an area, but substations are shown better with the "Water" overlay found in the "City planning overlays" section of the overlays tab.


Example of "Water facility" selected:


Example of "Cargo station" selected:

Note this type is not exclusive to the water and sewage stations; other cargo stations will be included too, like aggregate loading facilities and other general cargo stations.

These overlays display the pressure and flow of water and sewage in their pipe networks.
Pipes will also be colored to show the relative amount of flow or pressure to the pipe's limits, but these colors will not be updated when switching to one of these overlays unless the game is not paused.

"Water flow"
This overlay shows two things:
• Amount of water leaving a building (with an exception).
• How close to a pipe limit the flow in a pipe is.

At factories, the "Water flow" overlay only displays the water that workers are using. Industrial water usage rates are not included at the factory flow display, but it will be shown as a part of the water leaving any water distribution buildings, like switches.

Water pipes will also change color depending on how close they are to the pipe's maximum flow limit, with green representing low flow and red representing nearly maximum flow.

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"Water pressure"
This overlay indicates the inlet pressure of buildings with only one water inlet, and will highlight water pipes in various colors to represent how close they are to reaching the pipe's maximum pressure limit. Green represents low pressure, while red represents maximum pressure is being reached.

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"Sewage flow"
This overlay indicates the current flow through the sewage network. Sewage buildings like switches, substations, treatment plants, and discharges will display the amount of sewage flowing out of them.

Sewage pipes will also be highlighted in colors that relate the flow through the pipes to the pipe's flow limits. Green pipes represent low flow compared to the pipe's limit, while red pipes means sewage flow is close to the pipe's maximum flow limit.

There are a couple other overlays that are good to know about, but aren't specifically about water or sewage.

"Health"
→ Found under the "Citizens living preferences" section in the Overlays tab.

Since there is no alert for not having water at home nor for overflowing sewage, a low health warning is probably going to be one of your first indications of a water/sewage problem. The health overlay can show you lower than average health values for buildings before they really become an issue.


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"Heat water tank"
→ Found under the "Building properties" section in the Overlays tab.

This overlay is only mentioned because it has the word "water" in it, which may confuse new players. To be clear, it has nothing to do with the Water Management feature in the game; rather, it is used with the heating mechanics associated with the building energy's and seasons' temperature mechanics.

Other places you can find information for water and sewage features.

Unfortunately, there are no alerts for missing drinking water or overflowing sewage, so you will have to be vigilant in monitoring water/sewage flow or just respond to alerts for low health.

The "Tool for measurement" is found in the landscaping tools tab on the bottom menu bar, with the icon of a measuring tape. Since it is so useful, I recommend placing it on the hotbar so you can summon it with just one button press.

The main function it has that matters with water is the Elevation change, which reads the difference in elevation between the first and last points placed on the map. This difference in elevation is used a lot to predict the water flow from one building to another, and this is the easiest way to get it.


The elevation at the mouse cursor is also displayed at the top right.

For the best accuracy in predicting flow between buildings, you should always measure from the center of the building, as the building's actual elevation seems to be at its center (terrain may slope away from the center, giving a lower elevation than expected).

The list of vehicles and buildings is basically an index for all of the vehicles and buildings in your republic, which is handy when you are trying to find where a specific vehicle or building is, or if you want to monitor the conditions of your vehicles.

The range setting allows you to restrict the listed vehicles and buildings to just the nearby ones or you can look at all the ones on the map, as well as any vehicles or buildings off the map.

For water and sewage management, you can use this to ensure your water/sewage trucks are fueled and aren't too worn out to function, or to see where they all are headed.


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The list of buildings can also be used to quickly open the menus of various water/sewage buildings in your republic or to quickly check that all treatment plants are staffed. You can also look at water and sewage buildings to see if they lack power (they will have a red power icon to the left of their name) or if they need repairs or machine replacements.

Unfortunately the amount of water and sewage produced in a republic is not recorded, but the consumption, exporting, and importing of water is. Sewage usage does not seem to be recorded except for exports and imports, but since almost all water becomes sewage, you can just look at the amount of water consumed and conclude that the same amount of sewage was produced.

Quality and pollution percentage are not tracked either, and there is also no distinction between drinking water or industrial water; instead, all water is recorded under a category according to the building it was consumed in:
• Water consumption for residences and service buildings is recorded under "Citizen facilities."
• Water consumption for industry is recorded under "Industry."
• Water and sewage generation and treatment does not seem to be recorded at all.


There are two archives where records for sewage exports and water usage can be found:
• The "Economy and trade" tab (found in the left menu)
• At a "City hall / Accounting office"

Both the Economy and trade tab and the City halls / Accounting offices organize the information in the same way:
• Import & Export (Trade) - Records of imports and exports are found here.
• Domestic production & consumption - Records of production and consumption are found here.

The flow gauge in each building has a counter that records how much water has left the building (i.e. flowed through, consumed in, or loaded into a truck at the building), but unfortunately these counters are reset to zero whenever the game file is loaded (and also when you click on them), making them useful only in the short term.

The Economy and trade tab keeps track of all the resources produced, consumed, exported, and imported by your republic, all of which is recorded every four or five days.


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City halls / Accounting offices keep track of the local amount of resources produced, consumed, exported, and imported in the "City/area" they are a part of. The time when each resource was made/used/whatever is not recorded; instead you just have lump sums for the production, consumption, importation, and exportation of each resource since the the "City/area" (not the city hall /accounting office) was placed. Keep in mind that these records are always tracked in each "City/area" on the map; an accounting office simply reveals the records.


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Deleting a "City/area" will permanently erase all of the data recorded, which can be used to reset an area's records. Placing a new "City/area" with the "Create city/area" tool found in the "Terrain tools" section of the bottom construction menu, and then deleting the old area is the easiest way to do it.

The records for resources are split up into two categories, which are:
• Import & Export (Trade)
• Domestic production & consumption

The Economy and trade tab and City halls / Accounting offices both have these categories represented as tabs. If a row in the lists of either category is highlighted when you mouse over it, you can click on it to get a break down of that row for each resource.

The Economy and trade tab will also display the resource's record as a graph over the selected time frame when mousing over that resource. City halls / Accounting offices do not have this feature as they do not record the time along with the usage/trade.

Abandon all hope ye who enter here
It isn't that bad.

This section deals with all the in depth mechanics needed to calculate the pressure and flow of water with precision and accuracy, which depends on quite a few factors. These factors will be discussed in detail in the next few sections, but first a few basic concepts need to be explained. Do not forget that water substations have their own rules for pressure and flow.

If you just need a refresher, you can find a summary of all of the constants and equations for calculating water pressure and flow at the end of the guide.

Sewage flow is much more simple than water flow, so there is no advanced section on sewage.

Pressure in this game is the driving force of water flow, as water will only flow from tanks at higher pressures to tanks at lower pressures. This pressure difference will depend on a few factors, namely the sources of pressure involved and any special factors like pumps or switches.

Pressure is exerted by a couple sources:
• Height differences (three types: elevation changes, storage heights, and tank water levels)
• Pumps boost pressure in a few ways.

Switches cannot create pressure on their own, but they can reduce the amount of pressure needed to force water uphill.

These pressures are not exerted equally however, but in two ways:

• Internal Pressures - Storage height, tank level, and pump boosts are exerted at the building's inlets and outlets.
  
• Across a pipe - Change in pressures due to elevation and height "discounts" are applied across the pipe along with the difference in the internal pressures of the pipe's source and destination.

Pressure has a few properties you should be aware of:
• The pressure exerted on a building's inlets is not exerted through the building to its outlets.*
• Pressure across a pipe determines the maximum flow through that pipe.
• Pipe size limits the maximum pressure difference across it.
• Pipe size also scales the effect of pressure sources.
• Pressure and flow are "ideal" (i.e. there are no pressure drops from flow or system resistance.)
• The pipe's path has no influence on the pressure across it; only its endpoints' heights matter.

*That first property is pretty important, as since pressure is not exerted through buildings, it is very easy to waste the pressure gained from a large drop in height or from a pump. This is why an early start small pump can often only have an outlet pressure around 2 Bar even if it has an inlet pressure above 5 Bar. This is also why pumps or a drop in height is needed between all buildings for flow to occur.

When thinking of how pressure and flow are calculated and what factors are involved, it is easiest to think in terms of three scenarios:
• Tank to tank - Water simply flowing from a higher tank to a lower tank as a result of gravity.
• Pumped Flow - Water moving to or from a pump.
• Switch Flow - Water flowing through a switch.

This is because the pressure exerted by a difference in height will vary depending on whether a pump or switch is one of the buildings involved. Switches in particular ignore a lot of rules and can exhibit odd behaviors, such as allowing water to flow to an uphill tank without a pump:

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These are also the way the calculators provided in the guide are set up, but there may be situations where you will have to do manual calculations to estimate the flow. You also need to keep in mind that these models only predict the maximum flow a given pipe will be able to support; the actual flow of water will be limited to either the amount of water demanded by the buildings connected to the outlet of the pipe, or to the amount of water that can be supplied by other pipes and buildings to the inlet of the pipe.

All of these flow models will be discussed in the later sections once basic mechanics are covered.

The game only displays the difference in pressure across a pipe and this pressure can be read at both the outlet gauge of the pipe's source and the inlet gauge of the pipe's destination.

It should be noted that this displayed pressure is the sum of all pressure sources and influences across a pipe; while a building's internal pressure sources are accounted for, there is no in game indication just for them.

The unit for pressure in this game is the "Bar," which is an actual unit like psi or mmHg. In real life 1 Bar is exerted by a ~10 meter column of static water, but this is not the case in game, which can give different pressures for a given height of water depending on various factors.

For more information on pressure indications, consult the
┌( ♂ )┐ Indications and Overlays ┌( ♂ )┐ section.

Once you have the pressure difference across a pipe, calculating the maximum flow across it is pretty trivial. This maximum flow may not always be reachable for a few reasons though.

In most cases 1 Bar of pressure equals 24 m³/day of flow, regardless of pipes, but when pumps are involved maximum flow will be slightly higher (+1.5%).

Flow constant (F) = 24 m³/day-Bar, or 24 m³/day per Bar

There are some limitations to flow that can prevent the pipe from reaching the maximum flow:
• With an empty tank, a building's outlet flow cannot exceed its inlet flow.*
• With a full tank, a building's inlet flow cannot exceed its outlet flow or water consumption rate.*
• Flow cannot exceed a pipe's flow limit (with exceptions, especially with water switches.)
• Water treatment plants may limit outlet flow due to their limited processing capacity.

*For buildings with multiple inlets and/or outlets, the first two limitations consider the sum of the inlet flows and compare them to the sum of the outlet flows.

Flow can be observed through a couple ways, namely the flow gauges and overlay, but they can be misleading for a few reasons. I recommend you read the
┌( ♂ )┐ Indications and Overlays ┌( ♂ )┐ Section if you haven't already.

Pipes influence pressure by scaling the pressure generated by sources and by limiting how high the difference in pressure can be across them.

Pipes have a few properties that affect the maximum pressure and flow to and from buildings. Because pipes are always involved, you should always keep their effects in mind:

• The pressure created by most sources scales with pipe size:
  • A 10m drop exerts 0.615 bar, 0.273 bar, and 0.126 bar with large, medium, and small pipes.
  • Switch pressure is scaled off of the smallest pipe in the path of the water running through it.
  • Pipe size affects how high pumps can push or pull water up, but not their pressure boosts.
  
  This property is represented with the pipe constant k, with the values for each pipe size recorded in the table below.
  
  
• Pipes will limit the maximum pressure and thus flow between two buildings. If a pressure source like a pump creates more pressure than the pipe allows, the pressure will be reduced to the pipe's limit (mostly anyway; like electrical wires, the limit can be slightly exceeded).
  
  Water switches simultaneously obey and disregard this rule due to the overlapping of the water paths within them.
  
  
• The path taken to connect two buildings has no effect on the pressure or flow through a pipe.
  • Pipe length doesn't affect pressure nor flow.
  • A convoluted, twisting path behaves the same as a direct path.
  
  Consider the picture below with various pipe paths (1 through 4) connecting the inlet and outlet (red dots) of buildings A and B:
  
  .
  These paths (pipes 1 through 4) from the inlet of A to the outlet of B (shown as red dots) are all the same as far as pressure and flow are concerned; construction costs and times however, will not be.
  
  The main consequence of this is that you can choose to build shorter pipes to conserve the amount of steel the pipes require for construction, or you can follow the lay of the land (up and down hills) to minimize the amount of digging and thus time the pipe will need to be constructed (which can quickly become quite immense). You can also go around other underground infrastructure, such as metro tunnels or electric cables without losing pressure and flow.

These properties are summarized in this table:

More accurate k constants are equal to pipe flow capacity ÷ 2067, but this is kind of overkill.
A pipe's maximum flow rate equals the maximum pressure times the flow constant (24 m³/day per Bar).

The difference in height (▲h) is commonly used when estimating the pressure across a pipe, but it is not as simple as the difference in elevation between two buildings; buildings also have a storage height that is factored into the difference in height between them:

• A building's storage height is how far the bottom of its tank is from the ground it is built on. For example, water towers store their water above the ground while wells and reservoirs store their water below the ground.
  
  
• A building's storage height is defined in its .ini file with the tag: $WATER_STORAGE_POSITION
  Some buildings do not have this tag, but experiments have shown that the default storage height is about –0.9 meters.
  
  
• The game will compare the sums of each building's storage height and elevation to determine the change in height between two buildings' tanks:
  
  .
  The water tower's tank is higher than the reservoir's tank, despite being built at a lower elevation.
  
  
• The equation for difference in height is:
  ▲h = es + hs – (ed + hd), where
  •▲h = difference in height (in meters)
  • e = elevation, with s and d referring to the source or destination.
  • h = storage height, with s and d referring to the source or destination.
  If you're not sure which tank is the source, just assign the tank you wish to pull water from as the source. Elevation can be found using the tool for measurement.
  
  
• A list of the vanilla assets' storage heights can be found in the Equations - Water Pressure & Flow section.
  To find the storage heights of mod buildings, you will have to find and open the building.ini (configuration settings) files and look for the $WATER_STORAGE_POSITION values.

All buildings related to water have water tanks, which primarily is for their use or for sustaining flow between two buildings.

As a water tank fills up, the height of the water inside will exert a pressure on the tank's inlets and outlets. This height is proportional to both the cube root of the tank's capacity and the percentage that a tank is filled to.

The width/radius of all water tanks appears to be constant with their height (i.e. all tanks are horizontal shapes extruded vertically, like cubes and cylinders, not spheres nor conic shapes), so the height of the water within rises linearly in proportion to water volume rises. As tank capacity rises, so do all of its dimensions (height and width/length or radius).


.

The height of the water can be estimated with this equation:
h = 1.355 × a × Vmax^(1/3), where:
• h = the height of the water.
• a = the percentage to which the tank is filled.
• Vmax = the capacity of the water tank.


As a tank fills up with water, the difference in pressure across its inlet pipe will decrease while the difference in pressure across its outlet pipe rises. The amount of pressure exerted on an inlet/outlet will depend on the height (volume) of water in the tank, the size of the connected pipe, and whether a pump or switch is involved.

Pumps and switches can get a discount of sorts when pushing/pulling water uphill that is height based (more on that in the next section). Usually it is easiest to just use the height of the tank's water when calculating pressure with pumps or switches than it is to predict the tank's pressure, but when calculating tank to tank pressure, it can be easier to just estimate a tank's water pressure.

The maximum change in pressure (▲P) a building's storage tank will exert on its inlets and outlets can be approximated with the equation: ▲P = 1.355 × k × (Vmax^1/3), where
• ▲P = Maximum pressure the tank can exert, in Bar.
• Vmax = storage capacity of the tank in m³.
• k = the pipe constant of the pipe connected to the inlet or outlet in question.

A pump or switch may result in less pressure being exerted by the tank.

More accurate and easier to use equations are show below for each pipe size:
*Note that these are cube roots of Vmax, not Vmax raised to the power of 3.

The current pressure exerted by a water storage has a linear relationship to the current volume of stored water.; P = ▲P × a, where a = the percentage that the tank is filled to.

Some experimentally found pressure changes are shown below:

Pumps are the second source of pressure in the game, but they do this in three ways:
• Pumps share a flat boost among its inlet pipes and another flat boost among its outlet pipes.
• This pressure boost is not affected by the size (k constant) of a pipe.
• Pumps give connected pipes a discount on the pressure lost to

Pumps add a flat pressure boost to both their inlet and outlet sides that depends on their $ENGINE_SPEED tag value. This boost is then shared to all of the connected "active" pipes that water is flowing in.

If the pump is off or idle, then the boost goes away.

Pressure Boost Equation
The pressure boost for a pump can be predicted with this equation:
B = E ÷ 10, where:
• B = the pressure boost of the pump, in Bar.
• E = the $ENGINE_SPEED tag value of the pump.

The pressure boosts for the vanilla pumps can be found in the Equations - Water Pressure & Flow section, but for mod pumps you will have to open the config file and look up the $ENGINE_SPEED tag value or experiment in the game to find its pressure boost.


This boost in pressure is applied twice, once to the inlet side and once to the outlet side of the pump, but each side will split the boost it gets among the "active" pipes connected to them:

• A pipe is considered "active" if a pipe's destination can take water and its source can send it.
  
• A pipe is considered "inactive" if:
  • Its source cannot send water (empty, valve closed, unconnected),
  • Its destination cannot take any water (full, unconnected), or
  • It lacks enough pressure to send water, even with the pump's pressure boost (Pnet < 0 Bar).

Each active pipe will get a share of the boost equal to B ÷ n, where n is the number of active pipes connected to that side. This boost per pipe can be found with an equation similar to the one above:
b = E ÷ (10 × n), where:
• b = the boost for the inlet/outlet pipe, in Bar.
• E = the pump's $ENGINE_SPEED tag value.
• n = number of "active" pipes connected to the respective inlet or outlet side of the pump.

If a pipe connects two pumps, it will get the pressure boosts of both pumps, but this typically not useful because the flow into or out of the pumps will be limited by other factors or by the pipe's own pressure limit.

For example, the Early Start large pump can create boosts of 6 Bar for its inlet and outlet sides:

• If the inlet has two pipes that can supply water, then each inlet pipe will receive a boost of 3 Bar (= 6 Bar ÷ 2).
  
• If the pump's outlet side has three pipes that demand water, then each outlet pipe will receive a boost of 2 Bar (= 6 Bar ÷ 3).
  
• If one of the inlet pipes no longer supplies water (like if the source tank's valve is closed), it will no longer count as "active" and the other inlet pipe will get all of the boost (= 6 Bar ÷ 1).

The small pump can create a boost of 2 Bar, but since it only has one inlet and one outlet connection, its boost is never split.


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A source being empty and a destination being full are not the only cases where pipes will become "inactive." Disconnected pipes, shut valves, and insufficient pressure across the pipe (Pnet < 0) will also cause pipes to be seen as inactive by the pump.

There is no need to prime a pump nor will pumps experience cavitation. If you are wondering what that means, don't worry about it; it isn't emulated in the game.


Finally, if an active pipe is not using all of the flow its pressure can produce (due to a bottleneck or a pipe limit), it will give some of its boost back to the other pipes on its side of the pump. This can result in the pressures of other pipes being higher than expected, but their flow rates will usually not increase too much.


Unlike most sources of pressure, the pressure boosts of pumps are not affected by the connected pipes' sizes (i.e. no k constant effect). K constants will still affect other pressure sources acting on a pipe's net pressure though, such as the pump's tank level and storage volume, and differences in elevation; only the pump's pressure boost is unaffected.

This has two big consequences:

• Water can be pumped up to much higher heights (up hills or water towers) with smaller pipes than with larger ones.
  
• Sometimes for a pump, equal or even higher water flows can be achieved with a smaller pipe size when pumping uphill.

This is not to say that large pipes should never be used with pumps (quite the opposite), but there are niche cases where smaller pipes are better suited.


In addition to pipes getting a pressure boost from a pump, pipes also lose less pressure when pumping water uphill:
• Pressure loss from pumping from a lower source (▲h > 0) is reduced.
• Pressure loss from pumping to a higher destination (▲h > 0) is reduced.

Pressure gained from pumping downhill is not lost though:
• Pressure gained from a drop from a higher source is unaffected.
• Pressure gained from a drop to a lower destination is unaffected.

This effect is shown on the graph below:

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This uphill discount sets the pressure lost from pumping uphill to roughly 0.1147 times the normal amount lost.

Essentially for every 10m drop in height, large pipes get the full pressure gain of 0.615 Bar, but for every 10m gain in height, large pipes only lose about 0.071 Bar when a pump is involved. If no pumps nor switches are involved, then a large pipe will lose 0.615 Bar for every 10m gain in height.


Pumps have a few unique flow behaviors:

• First, the flow from/to a pump is ~1.5% higher than its pressure reading would suggest.
  Pump Flow = F × P × 1.015, where:
  • F is the 'Flow Constant' of 24 m³/day
  • P is whatever the indicated or calculated pressure is.
  (Keep in mind that pump pressure is still limited to the pipe's maximum pressure.)
  
  
  
• Second, the tank level of a pump will try to equalize its inlet and outlet flows. Since the tank level exerts pressure on both the pump's inlets and outlets, it will hinder inlet flow and bolster outlet flow as it fills and vice versa as it empties.
  
  Unfortunately, this really only matters when the flows are somewhat close due to the small size of the pump's tank; once the tank is completely filled or emptied, the tank will stop trying to equalize the flow.
  
  The actual flow rate the pump can sustain will be limited to the lower flow rate of its inlet or outlet. Typically a pump's throughput will be close to its pressure boost, unless pumping uphill from either side (less than the pressure boost) or if both sides are pumping downhill (higher than the pressure boost).
  
  
  
• Finally, a pump will not draw from multiple water sources equally; instead, it will fully load one inlet pipe until it reaches its flow/pressure limit before the pump starts to draw from another inlet pipe.
  
  This is good for maximizing the pressure boost for inlet pipes, as only one or two pipes will be active, but this also biases one of the pump's source over its other sources, which may not be what you want, especially if you have other sources pulling from the same source.

There is a third water pump in the base game: The water un/loading station, whose maximum pressure boost is 0.5 to 1 Bar. With the uphill pumping discount, this is enough to push water up to a big water tower at the same elevation, but the flow rate will still be pathetic (like 5 to 10 m³/day at most) and can require several days to unload or fill most water trucks.

You can always attach another pump to these stations to un/load trucks faster.

Water switches seem to abide by their own set of rules. They can allow water to flow from areas of low pressure to flow to areas of higher pressure, they can wildly exceed pipe flow and pressure limits, and they can raise water pressure on

I am unsure if this was an accident or a sacrifice for player convenience, so while you can exploit them, keep in mind that they may be revised at some point.

Water switches seem to have one to three paths of water flowing through them, which each start at the source end of the switch's inlet pipe and end at the respective outlet pipe's end.


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Each path's water pressure and flow are calculated separately with the switch's inlet pressure and the difference in height from the switch to the respective destination building as inputs, but there are some interesting quirks:

• The flow for a water path is constant across both sides of the switch, and it depends on the switch's outlet pressure.
  
  
• Likewise, the pressure and flow through a water path scale off of the smallest pipe size in the water path. For example, if a water path through a switch has a medium sized outlet pipe and a large inlet pipe, the k constant for the medium pipe will determine the resulting pressure and flow of the water path. If the large inlet pipe were downgraded to a medium pipe, the water path's flow and pressure would not change, but it would if either pipe were downgraded to a small pipe.
  
  
• Inlet pressure of the switch will drop by about 0.08 Bar when water is flowing, which may be related to the volume of the switch's tank (whether water is in the tank or not seems to be irrelevant.)
  
  
• A water path's inlet pressure minus 0.08 Bar and then divided by its pipe's k constant is proportional to the water path's outlet pressure and flow.
  
  
• The flow through the inlet pipe of a switch is equal to the sum of the flows of all the water paths passing through it.

If you chain water switches together, then the water paths are simply extended up to the inlet of the first water switch's inlet pipe, and as a result, if you chain a bunch of switches together, the outlet pressure of the last switch in the chain will determine the flow of the water path through the chain.

Because the outlet pressures of switches are not limited, it is possible to create very high pressures at the last switch's outlets, which then have a ridiculously high flow rate all along the water path to the first switch's water source.


Note that all pipes connected to the chain of two switches have the same flow rate, which exceeds the largest pipe's maximum flow rate limit.

The biggest limitations to this behavior is that large drops are needed between switches to raise the pressure and that there seems to be diminishing pressure returns from these drops, but there is also keeping the source supplied with enough water per day. Pumps cannot be placed between the switches because this would break the chain.


I also have not investigated this enough for a formula because it has a huge potential for exploitation and I don't expect for it to stick around forever, so I do not guarantee any accuracy in predicting the flow of water for a chain of water switches with the equation below.

For less exploitative distribution of water, such as from a water tower to a few buildings, you can keep the switches going downhill or on level ground and you should only gain pressure.


Pay very close attention to the input factors' definitions.

Flow through a water switch is calculated per outlet path with this unintuitive equation:
The equation uses a lot of factors:
• Poutlet = the outlet pressure for the water path, in Bar.*
• Pinlet = the inlet pressure of the switch, in Bar.**
• k = the pipe constant of the smallest sized pipe in the water path (inlet or outlet pipe).
• Ss = switch storage height. For vanilla water switches, this is always -3 meters.
• Es = switch elevation, in meters. Find this with the tool for measurement.
• Sd = destination's storage height. Found in the Equations - Water Pressure & Flow section.
• Ed) = destination's elevation. Find this with the tool for measurement.
• a = the percentage that the destination's tank is filled to.
• V = the maximum volume the destination's tank can hold.

*For some reason, switch path flow and outlet pressure don't always match; sometimes there is more flow than the switch's actual read outlet pressure would suggest, but rarely more than 5 m³/day.

**The inlet pressure must be converted to the pressure a large pipe would exert. This can be done by dividing it by the inlet pipe's k constant and multiplying it by the large pipe's k constant. You can either calculate this inlet pressure with the tank to tank or pump flow models discussed later or you can use the switch's inlet reading (the inlet reading may change once flow occurs though).

Unlike with other cases, the outlet pressures of a water switch are not constrained to their pipe's pressure limits, but the individual flow of each water path is limited to their pipe's maximum flow limit.

The inlet flow (as seen at the gauge at the switch's source) will be equal to the sum of all the switch's water paths. There are also no pressure nor flow limits to this sum; some setups can exceed 400m³/day of flow or have pipe pressures over 5.30 Bar.


For chained water switches, I suspect that you can take the outlet pressure of one switch, convert it to the pressure a large pipe would have, and then plug that into the equation above as Pinlet, but I am not sure if that works (this guide has consumed enough of my life; you'll have to figure it out on your own).


Switches have a few exploits thanks to their mechanics:

• Switches can multiply the height a pressure source can push water up to, to the point that switches can make water flow uphill without a pump. This happens because switches discount the pressure needed to force water uphill.
  
  For best results, try to place the switch at least at the same elevation as the source building. Building the switch below the source building is better, but only until the inlet pipe's pressure reaches the pipe's pressure limit (there is no pressure limit when its source is also a switch).
  
  
• If you need to move water a long distance by pipe, you can save money by using smaller or fewer pipes by using switches to exceed the flow limit through them. All you need to do is use the long stretch of piping as the inlet pipe to a switch with three active pipes with high flow.
  
  For example, a single medium pipe can be made to carry over 150 m³/day instead of its usual ~56 m³/day, which would save a lot of steel needed to upgrade it to a large pipe with a flow limit of only ~137 m³/day.
  
  
• On flat land, you can raise the pressure of a source a little bit by chaining switches together with a pressure rise of 0.03 Bar (or 0.72 m³/day) per switch. So if you need slightly more flow to a building than the source can provide, you can simply add some switches to its supply line rather than a pump. Lowering the water switches' elevation helps a bit too (more depth is better).
  

Tank to tank flow is the most basic transfer of water between two buildings, as gravity is the only source of pressure, no "discounts" are in effect, and switches and pumps are not involved.

Basically, water flows from a source tank to a destination tank when its height is higher than the destination tank's height because of the pressure created by the difference in height. The exact amount of pressure depends on the size of the piping connected between them and the difference between the source and destination heights (elevation, storage height, water level).

Remember that there are limits to pressure and flow though; for example, the pressure from the difference in height cannot exceed the pipe's maximum pressure limit, nor can the pressure be negative and result in flow.

The following steps can be taken to estimate flow.

1. Determine the change in height from the source tank to the destination tank.
2. Determine the water height in both tanks or their change in pressure from empty to full.
3. Combine these factors to get a total change in height.
4. Multiply this total change in height by the pipe constant (k) to get the net pressure.
5. Check if net pressure exceeds the pipe's pressure limit or if it is less than zero.
6. Multiply the net pressure by the flow constant (F) to get the expected flow.

You could also find the net pressure by calculating the ▲h between the water tanks, multiplying it by the k constant, and then adding it to the calculated pressures exerted by the water levels of both tanks. Both methods are discussed below.


The change in height (▲h) provides the main source of pressure and depends on the difference between the source tank's elevation and storage height and the destination tank's elevation and storage height.


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Elevation for both tank's buildings (Es and Ed) can be found using the "Tool for measurement," while the tank's storage heights (Ss and Sd) have to be looked up. Once you have all four heights, you simply need to subtract the destination tank's heights from the source tank's heights:

▲h = Ss + Es - Sd - Ed

The water inside of tanks will also exert pressure, so their effect must be calculated too. This can be done either by finding the height of the water or the pressure it exerts.

Height is easy to find as you only need to know the volume of the storage tank, the percentage that the tank is filled to, and this equation:
h = a × 1.335 × V^(1/3), where:
• a is the percentage the tank is filled to.
• h is the height of the water level in the tank.
• V is the volume of water the tank can hold (usually found in the menu of the tank's building).

You can also calculate the pressure that the water will exert in a tank, which can be slightly more accurate than calculating heights via the general equation for tank heights (there is some variance). You will have to use the tank pressure equation that corresponds with the pipe's k constant, which can be found in the Equations - Water Pressure & Flow section:

If you want to know if the maximum flow will be higher than what downstream consumers use (i.e. ensure they have enough water for full production), then you should assume that the source tank never has water (a = 0%) and that the destination tank is always full (b = 100%), as this will result in the lowest maximum flow as far as the tank volumes are concerned.


Putting it all together, we get these equations for the net pressure across the pipe for tank to tank flow:

• Ptanks = k × ( Ss + Es - Sd - Ed + 1.335 × ( a × hs - b × hd ) )
  (Using height of water levels in tanks.)
  
  
• Ptanks = k × ( Ss + Es - Sd - Ed ) + a × Ps - b × Pd
  (Using pressures from the water in tanks.)

Since there are no other factors affecting pressure in tank to tank flow, Pnet = Ptanks.

Pnet is the net pressure across the pipe, but this cannot exceed Pmax of the pipe nor be less than zero. The rest of the variables are summarized below:

• Ss = Storage height of source
  
• Sd = Storage height of destination
  
• Es = Elevation of source
  
• Ed = Elevation of destination
  
• k = Pipe constant of the pipe connecting the two water buildings.
  
• Vs = Maximum tank volume of the source.
  
• Vd = Maximum tank volume of the destination.
  
• Ps and Pd = the pressures exerted by the water in the source and destination tanks.
  
• a & b = the percentage that the respective tanks are filled to.

If pressure is greater than the pipe's maximum pressure limit, then the pressure will be clamped to this limit. Pressures below zero Bar result in no flow.


To calculate the maximum flow rate, you simply need to multiply Pnet by the flow constant:
Max Flow = Pnet × 24 m³/day-Bar.

For example, a Pnet of 4 Bar should result in a maximum flow of around 96 m³/day:
4 Bar × 24 m³/day-Bar = 96 m³/day.

The actual water flow may be less for reasons discussed in the Mechanics - Water Flow section.

Don't forget that there is a final flow of water from the substation to buildings, which is affected by elevation.

When a pump is involved, the tank to tank flow model is no longer sufficient, as there are two new factors at play; the pump will add a set amount of pressure to the pipes it is connected to and the pressure needed to pump water uphill is a fraction of the pressure that height exerts.

The pump flow model is basically the tank to tank model with the pump's effects added in.

The following steps can be taken to estimate flow with a pump involved:

1. Determine the change in height from the source tank to the destination tank.
2. Determine the water height in both tanks or their change in pressure from empty to full.
3. Combine these factors to get a total change in height.
4. Multiply this total change in height by the pipe constant (k) to get the tank to tank net pressure.
5. If tank to tank net pressure is less than zero, then multiply it by the discount multiple.
6. Add the pump's pressure boost to get Pnet.
7. If Pnet exceeds the pipe's pressure limit, reduce it to the pipe's limit.
8. Multiply Pnet by the flow constant (F) to get the expected flow.


First the tank to tank pressure needs to be found:
• Ptanks = k × ( Ss + Es - Sd - Ed + 1.335 × ( a × hs - b × hd ) )
or
• Ptanks = k × ( Ss + Es - Sd - Ed ) + a × Ps - b × Pd

Then check if Pnet is less than zero Bar to see if the uphill pumping discount applies:
• If it is, then multiply k × ( Ss + Es - Sd - Ed ) by 0.1147, then add the tank component.
• If not, continue on.


Next the pump's pressure boost needs to be found. Keep in mind that each side of the pump (inlet & outlet) get the same raw boost from the pump, but these boosts are split out among all of their respective connected pipes when water flows through them.

Because the pump inlet's and outlet's pressure boosts are split among the pipes connected to the respective inlet and outlet side of the pump, it is usually safer to assume all pipes connected to the pump have water flowing through them and thus the boosts are split among them; so if your large pump has three pipes connected to each side, you should assume n = 3 for both sides so you can see if the minimum flow will always be enough for whatever you're planning to supply.

For vanilla pumps you can look up its pressure boost value in the Equations - Water Pressure & Flow section and divide it by the number of pipes connected to the pump, but the pressure boosts for mod pumps will need to be calculated with the equation explained in the Mechanics - Pumps section:
b = E ÷ (10 × n), where:
• b = the boost for the inlet/outlet pipe, in Bar.
• E = the $ENGINE_SPEED tag value.
• n = number of "active" pipes connected to the respective inlet or outlet side of the pump.


Now we can put it all together to get the net pressure across the pipe (Pnet) going to/from the pump. Because the pump's pressure boost is not affected by pipe size (and thus its k constant), we can just add it to the tank to tank pressure we calculated earlier:

Pnet = Ptanks + b, where:
• Pnet = The pressure across the pipe, in this case with a pump involved.
• Ptanks = The pressure across the pipe due to gravity and tank volumes.
• b = The pressure added by the pump and distributed among all its inlet or outlet pipes.

Then we do the normal pressure checks:
• If Pnet exceeds the pipe's pressure limit, then Pnet = the limit.
• If Pnet is still less than zero, then there will be no flow.

Finally we can see the maximum flow for the pipe, but remember that pumps get a little extra flow:
Pump Flow = F × P × 1.015, where:
• F is the 'Flow Constant' of 24 m³/day
• P is whatever the indicated or calculate pressure is for the pipe.

To get the average flow through the pump, you'll have to do this process again for each other pipe connected to the pump and then sum them together to get the net inflow and outflow of the pump. Generally a pump's actual flow rate will trend to the side (inlet or outlet) with the lowest pressure/flow, which typically is whichever side is pumping water uphill.

Don't forget that there is a final flow of water from the substation to buildings, which is affected by elevation.

Flow with water switches involved deviates significantly from the other models:
• The outlet pressure of a switch depends on its inlet pressure.
• The inlet flow is the sum of all outlet flows.
• Pressure and flow limits are sometimes ignored.
• Water paths overlap on the inlet pipe.

Thus we need an entirely different flow model to calculate water switch flow with, and the tank to tank and pump flow models will not suffice. Also due to the "path" system used for switches, each path will have to be calculated individually and summed to obtain the switch's inlet flow.

Water switches are not very intuitive (or at least, I could not find all the underlying mechanics), so we basically just have to plug numbers into an equation to get an estimate for each water path and then add up each path's flow to obtain the inlet pipe flow.

Remember that this is the equivalent pressure for the expected flow (the switch's actual outlet pressure readings will usually be lower) and there is some error in the equation (like up to 5 m³/day).

Essentially the steps are:
• Figure out the pressure at the switch's inlet with the tank to tank or pump flow models.
• For each path, figure out the relevant factors for the equation (pay close attention to definitions).
• For each path, plug these factors into the equation to obtain the equivalent pressure.
• Multiply each path's equivalent pressure to get the flow for each path.
• Sum the flow of each path to get the total flow of the switch's inlet pipe.


The pressure through a path of a water switch is calculated with the equation below:
The equation uses a lot of factors:
• Poutlet = the outlet pressure for the water path, in Bar.*
• Pinlet = the inlet pressure of the switch, in Bar.**
• k = the pipe constant of the smallest sized pipe in the water path (inlet or outlet pipe).
• Ss = switch storage height. For vanilla water switches, this is always -3 meters.
• Es = switch elevation, in meters. Find this with the tool for measurement.
• Sd = destination's storage height. Found in the Equations - Water Pressure & Flow section.
• Ed) = destination's elevation. Find this with the tool for measurement.
• a = the percentage that the destination's tank is filled to.
• V = the maximum volume the destination's tank can hold.

*For some reason, switch path flow and outlet pressure don't always match; sometimes there is more flow than the switch's actual read outlet pressure would suggest, but rarely more than 5 m³/day.

**The inlet pressure must be converted to the pressure a large pipe would exert. This can be done by dividing it by the inlet pipe's k constant and multiplying it by the large pipe's k constant. You can either calculate this inlet pressure with the tank to tank or pump flow models discussed earlier or you can use the switch's inlet reading (the inlet reading may change once flow occurs though).

**Note that Pinlet cannot exceed the pipe's pressure limit unless the water switch's inlet is connected to the output of another switch. The pressure from a pump or from a tank to a water switch is still limited to the pipe's maximum pressure, though the flow is not.


To obtain the flow, we simply multiply the pressure calculated above with the flow constant (F):
Fpath = Poutlet × 24 m³/day-Bar

Unlike with the other flow models, pressure and flow limits of pipes are ignored by a water switch's outputs, but flow still will not occur if Pnet < 0 Bar.


Repeat these equations for all water paths and then sum their outlet flows to get the inlet flow to the switch from its source. Keep in mind that you are likely to get a small error in each flow, so plan for an extra allowance just in case.

Don't forget that there is a final flow of water from the substation to buildings, which is affected by elevation.

Equations and constants for water that do not relate to calculating flow are listed here.

Quality = W ÷ V × 100%, where:
• W = volume of "pure water" in the sample.
• V = volume of the entire water sample.

Pollution % = P ÷ V × 100%, where:
• P = volume of "pollutants" in the sample.
• V = volume of the entire sewage sample.

Volume of pollutants in sewage:
P = Pollution % × V ÷ 100%, where:
• P = volume of "pollutants" in the sample.
• V = volume of the entire sewage sample.

Volume of pollutants in water:
P = (100% - Quality) × V ÷ 100%, where:
• P = volume of "pollutants" in the sample.
• V = volume of the entire sewage sample.

We use (100% - Quality) because we want to measure pollutants, not pure water.

For calculating how much volume a treatment plant can process for various input water quality or sewage pollution %:

• Maximum quality rise while maintaining maximum flow of processed water/sewage:
  ▲Q = P ÷ F, where:
  • ▲Q = maximum rise in quality or fall in pollution %.
  • P = maximum volume of pollutants the plant can remove per day.
  • F = maximum volume of water/sewage the plant can process a day.
  
  
• Maximum volume of water the plant can process a day for a given rise in quality:
  F = P ÷ (▲Q), or F = f; whichever is lower:
  • F = the expected flow of processed water/sewage from the treatment plant.
  • f = the maximum flow rate limit of the plant; flow cannot exceed this limit.
  • P = the volume of pollutants the treatment plant can remove a day.
  • ▲Q = the change in water/sewage quality.

Remember that the "quality" of sewage is equal to 100% - pollution %:
• Setting an 85% quality goal at a sewage treatment plant is setting the desired pollution % to 15%.
• ▲Q = incoming pollution % minus outgoing pollution % = outgoing quality - incoming quality.


Chemical usage can be estimated with these equations:

• R = C × P ÷ W, where:
  • R = The rate that chemicals are used at, in tons per day.
  • C = The treatment plant's rate of chemicals consumption at maximum production.
  • P = The volume of pollutants removed per day, in m³/day.
  • W = The maximum volume of pollutants the treatment plant can remove each day.

This equation can be expanded to the factors shown in the treatment plant's menu:

• R = C × V × (▲Q) ÷ W, where:
  • R = The rate that chemicals are used at, in tons per day.
  • C = The treatment plant's rated consumption of chemicals at maximum capacity.
  • V = The volume of water flowing through the treatment plant, in m³/day.
  • ▲Q = The rise in water quality (remember to convert ▲Q to a decimal: 1% = 0.01).
  • W = the Maximum amount of pollutants the treatment plant can remove each day.

F = 24 m³/day per Bar
• Remember that pumps and switches can get more than this.

*Flow rate limits can be slightly exceeded when connected to pumps, while pipes connected to switches can wildly exceed the pressure and flow rate limits.

More accurate k constants can be approximated to pipe flow capacity ÷ 2067, but this is kind of overkill.

Pipe capacity ≈ Flow constant × Maximum Pressure.

Pipe inlets' and outlets' heights do not affect anything but pipe depth, which is only important for figuring out the cost of a pipe (deeper = more digging time and boards needed); Do not use them for flow calculations.

Storage height affects how the game interprets the difference in height between two buildings.

If you don't see a tank volume listed here, you can find it listed in the building's popup in the building menu.


*When tested, -0.90m appears to be the default storage height for when the tag is not defined in the building's config file.

Flow = Pnet × F
• Flow is how much water moves through the pipe from the source.*
• F is the flow constant, which equals 24 m³/day per Bar
• Pnet is the Net Pressure across the pipe, this must be positive for flow to occur.
* The source's water meter displays the combined rate of water drawn from it by all connected pipes.

Pumps also get a 1.5% boost to flow, while switches may not have an accurate pressure displayed for their flow.

The height of water in a tank is equal to:
h = 1.355 × a × Vmax^(1/3), where:
• h = the height of the water.
• a = the percentage to which the tank is filled.
• Vmax = the capacity of the water tank.

The maximum change in pressure (▲P) a building's storage tank will exert on its inlets and outlets can be approximated with the equation: ▲P = 1.355 × k × (Vmax^1/3), where
• ▲P = Maximum pressure the tank can exert, in Bar.
• Vmax = storage capacity of the tank in m³.
• k = the pipe constant of the pipe connected to the inlet or outlet in question.

A pump or switch may result in less pressure being exerted by the tank.

More accurate and easier to use equations are show below for each pipe size:
*Note that these are cube roots of Vmax, not Vmax raised to the power of 3.

The current pressure exerted by a water storage has a linear relationship to the current volume of stored water.; P = ▲P × a, where a = the percentage that the tank is filled to.

Experimentally found pressure changes (▲P):

The pressure boost for a pump can be predicted with this equation:
B = E ÷ 10, where:
• B = the pressure boost of the pump, in Bar.
• E = the $ENGINE_SPEED tag value of the pump.

This boost in pressure is applied twice, once to the inlet side and once to the outlet side of the pump, but each side will split the boost it gets among the "active" pipes connected to them:

• A pipe is considered "active" if a pipe's destination can take water and its source can send it.
  
• A pipe is considered "inactive" if:
  • Its source cannot send water (empty, valve closed, nothing connected, etc.),
  • Its destination cannot take any water (full, not connected), or
  • It lacks enough pressure to send water, even with the pump's pressure boost (Pnet < 0 Bar).

Each active pipe will get a share of the boost equal to B ÷ n, where n is the number of active pipes connected to that side. This boost per pipe can be found with an equation similar to the one above:
b = E ÷ (10 × n), where:
• b = the boost for the inlet/outlet pipe, in Bar.
• E = the pump's $ENGINE_SPEED tag value.
• n = number of "active" pipes connected to the respective inlet or outlet side of the pump.

*Per side, with only one inlet or outlet pipe connected/running.

A building that is at a higher elevation than the substation it draws water from will have a different pressure and thus flow than said substation. This effect can be estimated by the equation:
Pb = Ps - (▲h × k × 0.1147), where:
• Pb = Pressure at the building.
• Ps = the inlet pressure of the substation.
• ▲h = the elevation of the building minus the elevation of the substation.
• k = the pipe constant.

Equations for each flow model are listed here.

If a pipe is not connected to a pump nor the outlet of a switch, then its pressure will be equal to:

• Ptanks = k × ( Ss + Es - Sd - Ed + 1.335 × ( a × hs - b × hd ) )
  (Using height of water levels in tanks.)
  
  
• Ptanks = k × ( Ss + Es - Sd - Ed ) + a × Ps - b × Pd
  (Using pressures from the water in tanks.)

Since there are no other factors affecting pressure in tank to tank flow, Pnet = Ptanks.

Pnet is the net pressure across the pipe, but this cannot exceed Pmax of the pipe nor be less than zero. The rest of the variables are summarized below:

• Ss = Storage height of source
  
• Sd = Storage height of destination
  
• Es = Elevation of source
  
• Ed = Elevation of destination
  
• k = Pipe constant of the pipe connecting the two water buildings.
  
• Vs = Maximum tank volume of the source.
  
• Vd = Maximum tank volume of the destination.
  
• Ps and Pd = the pressures exerted by the water in the source and destination tanks.
  
• a & b = the percentage that the respective tanks are filled to.

If pressure is greater than the pipe's maximum pressure limit, then the pressure will be clamped to this limit. Pressures below zero Bar result in no flow.

First the tank to tank pressure needs to be found:
• Ptanks = k × ( Ss + Es - Sd - Ed + 1.335 × ( a × hs - b × hd ) )
or
• Ptanks = k × ( Ss + Es - Sd - Ed ) + a × Ps - b × Pd

Then check if Pnet is less than zero Bar to see if the uphill pumping discount applies:
• If it is, then multiply k × ( Ss + Es - Sd - Ed ) by 0.1147, then add the tank component.
• If not, continue on.

Then find the pump boost for the pipe:
b = E ÷ (10 × n), where:
• b = the boost for the inlet/outlet pipe, in Bar.
• E = the $ENGINE_SPEED tag value.
• n = number of "active" pipes connected to the respective inlet or outlet side of the pump.

Add it all together:
Pnet = Ptanks + b, where:
• Pnet = The pressure across the pipe, in this case with a pump involved.
• Ptanks = The pressure across the pipe due to gravity and tank volumes.
• b = The pressure added by the pump and distributed among all its inlet or outlet pipes.

Then do the normal pressure checks:
• If Pnet exceeds the pipe's pressure limit, then Pnet = the limit.
• If Pnet is still less than zero, then there will be no flow.

Finally calculate the maximum flow for the pipe; remember that pumps get a little extra flow:
Pump Flow = F × P × 1.015, where:
• F is the 'Flow Constant' of 24 m³/day
• P is whatever the indicated or calculated pressure is for the pipe.

To get the average flow through the pump, you'll have to do this process again for each other pipe connected to the pump and then sum them together to get the net inflow and outflow of the pump. Generally a pump's actual flow rate will trend to the side (inlet or outlet) with the lowest pressure/flow, which typically is whichever side is pumping water uphill.

The pressure through a path of a water switch is calculated with the equation below:
The equation uses a lot of factors:
• Poutlet = the outlet pressure for the water path, in Bar.*
• Pinlet = the inlet pressure of the switch, in Bar.**
• k = the pipe constant of the smallest sized pipe in the water path (inlet or outlet pipe).
• Ss = switch storage height. For vanilla water switches, this is always -3 meters.
• Es = switch elevation, in meters. Find this with the tool for measurement.
• Sd = destination's storage height. Find this in the Equations - Water Pressure & Flow section.
• Ed) = destination's elevation. Find this with the tool for measurement.
• a = the percentage that the destination's tank is filled to.
• V = the maximum volume the destination's tank can hold.

*For some reason, switch path flow and outlet pressure don't always match; sometimes there is more flow than the switch's actual read outlet pressure would suggest, but rarely more than 5 m³/day.

**The inlet pressure must be converted to the pressure a large pipe would exert. This can be done by dividing it by the inlet pipe's k constant and multiplying it by the large pipe's k constant. You can either calculate this inlet pressure with the tank to tank or pump flow models discussed earlier or you can use the switch's inlet reading (the inlet reading may change once flow occurs though).

**Note that Pinlet cannot exceed the pipe's pressure limit unless the water switch's inlet is connected to the output of another switch. The pressure from a pump or from a tank to a water switch is still limited to the pipe's maximum pressure, though the flow is not.


To obtain the flow, we simply multiply the pressure calculated above with the flow constant (F):
Fpath = Poutlet × 24 m³/day-Bar

Unlike with the other flow models, pressure and flow limits of pipes are ignored by a water switch's outputs, but flow still will not occur if Pnet < 0 Bar.


Repeat these equations for all water paths and then sum their outlet flows to get the inlet flow to the switch from its source. Keep in mind that you are likely to get a small error in each flow, so plan for an extra allowance just in case.

Equations and constants for sewage are listed here.
For treatment plants, see the Equations - Water Quality & Treatment section.

Only information that is not displayed in the game's GUI is listed here.

Cost = P ÷ 0.52 × V × P%, where:
• Cost = the approximate fee required to export a volume of sewage.
• P = Price of waste water listed at the customs house.
• V = Volume of sewage you want to export.
• P% = the pollution % of the sewage you want to export.

A listing of the various buildings' sewage connection depths, as well as some additional info.

*The Chemical plant is only -3.0m.

If not listed, the building's sewage will have a effluent pollution of ~52.0% (due to citizens).

*This depends on the quality setting you set there.
Keep in mind that pollution % = 100% - quality.
**There is still waste water from workers.

You will have to look in a mod's config file to find its industrial effluent pollution percentage, which is defined after the tag: $PRODUCTION_SEWAGE_POLLUTION

Also keep in mind that these pollution % are only for the industrial waste water. If a building (except for sewage treatment plants) does not have an outlet pipe for industrial sewage or if you merge the industrial and worker waster water into a sewage switch, then the actual pollution % of the effluent discharged to a sewage tank will be a mix of industrial and worker effluent per the formula:

• M = Σ (Vn × P%n) ÷ Σ Vn, where:
  • M = Mixed sewage pollution %
  • Σ (Vn × P%n) = The sum of each volume of sewage (Vn) times its own pollution % (P%n).
  • Σ Vn = The sum of all sewage volumes.

Here is a list of minimum ranges to maintain between an outlet for various pollution percentages.

So far, it seems that releasing even modest amounts of untreated sewage pollutes quite an area around it.

This section has links and instructions for various calculators you can use to estimate pressure and flow for a variety of situations.

Once you open a link to a calculator, expand the expression list on the left so it takes up most of the screen; the graph portion is not used.

If you need to reset the graph for any reason, just click on the link again.


Despite my best efforts, and due to the effects of time acceleration and other fluctuations in the water system, the calculators for pumps and switches may be off by up to 5 m³/day or 0.21 Bar (typically the error will be less). I choose to set the calculators to err on the lower end of the results so that you should get at least the amount predicted, but if you get a lot more or less flow or pressure than expected, you should check your inputs again.

These calculators return the highest pressures and flow possible for a specific pipe segment, switch, or pump, but you may not see this maximum flow/pressure if flow or pressure is throttled in upstream or downstream pipe segments, switches, and pumps.

Modded water management buildings should follow the equations I found, but I do not guarantee any degree of accuracy when mods are involved, especially for mod switches. You will also have to look up the storage heights of any mods you use.

I would also recommend that you pad your planned flow requirements with a few m³/day of flow to ensure that flow will meet demand in case of errors. This extra flow also helps to refill destination tanks if service was suspended for some reason.


https://www.desmos.com/calculator/lkpbmuqbvv
This calculator can be used to estimate the pressure and flow between two buildings provided neither is a pump nor a switch, and it can be used to calculate input values for switches.

Estimated pressure and flow will be displayed in the rightmost columns and will automatically be clamped to the pipe's maximum pressure.


You will need to plug in numbers for the following expressions:

• Ss = Storage height of source
  
• Sd = Storage height of destination
  You can find the storage heights in the Equations - Water Pressure & Flow section.
  
  
• Es = Elevation of source
  
• Ed = Elevation of destination
  Elevations can be found using the "Tool for measurement."
  
  
• k = Pipe constant of the pipe connecting the two water buildings.
  You can simply enter l, m, or s for the corresponding pipe size.
  
  
• Vs = Maximum tank volume of the source.
  
• Vd = Maximum tank volume of the destination.
  If you want pressure or flow calculated with partially filled tanks, you can assign the percentage of the source's tank to "a" and the percentage of the destination's tank to "b;" both of which can be found at the bottom of the expressions list.

https://www.desmos.com/calculator/1pqxuhqcij
This calculator can be used to find the pressures and flows of a pump's inlet(s) and outlet(s), but is a little more complicated to use than the others (I can only automate so much).

The resulting estimates should be pretty close to what the game shows, but this assumes that there are no bottlenecks upstream or downstream of the pump. For example, if you can only supply the pump with 30 m³/day of water, the pump will only push 30 m³/day even if it theoretically could do more.


To obtain the correct estimates, follow these steps:

1. Plug in the numbers as listed below.
   
2. Adjust the sliders for the number of active inlet and outlet connections (n & N).
   
3. Adjust the % that the source and destination tanks are filled to (a & c).
   
4. Then adjust b as follows:
   - If inlet flow > outlet flow, raise b until it equals one or the inlet and outlet flows are equal.
   - If inlet flow < outlet flow, lower b until it equals zero or the inlet and outlet flows are equal.

Note that for pumps with multiple inlet and outlet connections, you will have to compare the sum of the inlet flows to the sum of the outlet flows.

There are two tables in the pump calculator; the top one calculates the pressure and flow for the inlet of the pump while the bottom one calculates the outlet pressure and flow.

Pump variables to enter in:

• kin = Pipe constant of the pump's inlet pipe.
  
• kout = Pipe constant of the pump's outlet pipe.
  
• Ep = $ENGINE_SPEED tag value of the pump.
  
• Vp = Tank volume of the pump.
  
• hp = Elevation of the pump.
  
• Sp = Storage height of the pump.

Source and destinations to enter in:

• Vs & Vd = Tank volumes of the (s)ource and the (d)estination buildings.
  
• hs & hd = Elevations of the (s)ource and the (d)estination buildings.
  
• Ss & Sd = Storage heights of the (s)ource and the (d)estination buildings.

There are also five sliders you need to adjust:

• a = the % that the source's tank is filled to.
  
• b = the % that the pump's tank is filled to.
  (Adjust this after everything else is entered per the instruction above.)
  
• c = the % that the destination's tank is filled to.
  
• n = the number of inlet pipes the pumps is actively drawing water through.
  
• N = the number of outlet pipes the pump is actively sending water through.

Note that each inlet and outlet pipe requires its own calculation.

For maximum pressure and flow calculations, set a to one, and c to zero.


https://www.desmos.com/calculator/k5vnylhejq
This calculator can be used to find the flows and pressures associated with a switch, but it is probably the least accurate (but still pretty accurate) of all the calculators due to the weirdness of switches. Error tends to increase as ▲h approaches zero, but it shouldn't exceed +5 m³/day or +0.21 Bar.

Estimated pressure and flow will be displayed in the rightmost columns and will automatically be clamped to the pipe's maximum pressure, but keep in mind that this is only for one path of water through the switch.

You will need to plug in numbers for the following expressions:

• Pinlet = The calculated pressure at the inlet of the switch with a large pipe connection.
  You can calculate this using the tank to tank equation or calculator.
  
  
• k = The Pipe constant of the smallest pipe in the path of water you want an estimate for.
  You can simply enter l, m, or s for the corresponding pipe size.
  
  
• Ssw = The storage height of the switch. This is always -3 meters for a vanilla switch.
  
• Sd = The storage height of the destination.
  You can look up storage heights in the Equations - Water Pressure & Flow section.
  
  
• Esw = The elevation of the switch.
  
• Ed = The elevation of the destination.
  Elevations can be found using the "Tool for measurement."
  
  
• Vd = Maximum tank volume of the destination.
  If you want pressure or flow calculated with a partially filled destination tank, you can set "a" to the percentage that the source's tank is filled to.

This calculator can be used to predict flow for chains of water switches, but the pressure will not be correct for the flow (neither in game or in the calculations). Sometimes the discrepancy is equal to 0.08 Bar times the number of switches in the chain, but not always. For planning purposes though, this seems to be conservative.

I have made some other guides that I like to think are pretty useful.


Electricity Guide:
- Explains all of the limitations and mechanics of power in the game.
- Explains why your power is messed up.
https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=2827443475

Guide on Personal Cars:
- Covers how to use personal cars and some general info on road mechanics.
https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=2840936507

Guide to Trains:
- Explains the mechanics of trains, signals, metros, and more in detail.
- Also covers some advanced uses of trains, such as using RDOs as rail yards.
https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=2965408165

Ship, Aircraft, and Container Stats:
- Lists of stats for various vehicles, including speed, capacity, fuel economy, takeoff distance, etc.
- Lists Infrastructure characteristics, farm yield factors, electronics production over time, etc.
https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=3146397536

Questions and tasks I may work on later, if I can muster the willpower/alcohol:

• What is the experimental default value for (no tag) sewage storage heights?
  (does this even matter?)
  
  
• Are both the maximum water processed and max pollutants reduced by low worker staffing/productivity or is only one affected?
  
  
• Make a table of pollution ranges per pollutant level and sewage flow rates.
  
  
• Find an equation or make a table for the actual value of various mixes of pure water and pollutants in water and sewage (they seem non-linear).