- Plan B: Terraform water begins forming as the global average temperature approaches approximately -20°C.
- Elevation matters because low-ground ancient seas can become water before higher terrain.
- Map planning should prioritize cities and resource routes above likely flood zones.
- Water management relies on walls, dams, and pumps rather than attempting to empty entire oceans.
- Flooded cities may relocate population instead of immediately ending the settlement.
Plan B: Terraform Water Triggers
Plan B: Terraform water is tied to planetary warming rather than a simple unlocked level event. As greenhouse gases raise the global average temperature, water begins to evaporate from low-lying ancient sea areas. The first visible formations can appear close to -20°C, with community observations placing the transition around -19.8°C to -20°C.
The temperature shown on the main interface is a global average. Local temperatures can differ because the planet has regional conditions and seasonal variation between hemispheres. This explains why liquid water may appear while some locations still display freezing local readings.
Video Highlights:
- Water-related changes during the Worlds of Fire and Water expansion.
- Planetary transformation as climate conditions develop.
- A visual overview of the game’s changing terrain and water systems.
Do not treat the first visible stream as the only water event. Additional streams, rivers, and larger bodies of water can appear as the planet becomes warmer.
| Climate Stage | Approximate Global Average | What to Expect | Planning Response |
|---|---|---|---|
| Cold early phase | Below -20°C | Ancient lowlands remain mostly dry | Survey elevation and reserve city sites |
| Water transition | Around -20°C | Groundwater begins appearing in low areas | Review blue areas and protect low routes |
| Active warming | Above the transition | Streams and water surfaces expand or emerge | Keep infrastructure away from drainage paths |
| Warm later phase | Significantly warmer | More rivers, flow paths, and flooding risks | Use barriers, pumps, and elevated layouts |
The exact visual timing can vary slightly depending on the planet and how quickly its temperature changes. A city that is safe during the initial settlement phase may become exposed later if newly formed water follows the terrain toward it.
The safest approach is to treat the temperature threshold as an early warning. Before continuing aggressive warming, inspect the elevation around every city, industrial area, and resource connection. This gives you time to relocate construction or prepare defensive water infrastructure.
Elevation, Cities, and Map Selection
Elevation is the most important factor when choosing where to establish cities. Low terrain is more vulnerable because water begins in ancient sea areas and then follows the contours of the planet. Cities located on elevated ground generally have more time to respond when water systems expand.
City locations commonly appear above lower flood-prone terrain, but generation can still produce settlements or important sites in dangerous areas. Do not judge a location only by its current appearance. Inspect elevation values and the water view before committing major construction.
Move the cursor across candidate city areas and key resources to inspect elevation information. A location that looks dry may still sit inside a future drainage basin.
High Ground
- Best long-term safety
- More distance from ancient seas
- Better protection from expanding streams
- Preferred location for major cities
Low Ground
- Faster exposure to new water
- Greater flood preparation required
- Risky for permanent infrastructure
- Useful only with a clear mitigation plan
River Corridor
- Strong connection to flowing water
- Can become a major obstacle later
- Requires careful road and building placement
- Protect with walls or pumps when practical
| Site Factor | Lower-Risk Choice | Higher-Risk Choice |
|---|---|---|
| City elevation | Above surrounding lowlands | Near ancient sea terrain |
| Resource route | Elevated continuous path | Route crossing a basin |
| City center | Outside visible blue areas | Inside or beside blue areas |
| Nearby river | Controlled channel | River through the settlement |
| Expansion space | Broad high plateau | Narrow low valley |
A strong starting map often has most important land and resources above the first expected water line. However, elevation alone does not solve every problem. Water can travel downhill, new streams can appear, and a river may develop through an area that was previously dry.
Fluoride access is another strategic consideration when evaluating a world. A useful map should provide at least one practical route toward fluoride deposits near or within the icecaps while still offering elevated sites for cities and production. Resource access and flood safety should be evaluated together rather than separately.
| Priority | Check Before Starting | Why It Matters |
|---|---|---|
| 1 | City elevation | Determines early exposure to rising water |
| 2 | Resource elevation | Prevents critical routes from being cut off |
| 3 | Water-view colors | Shows whether a site is already in a risky area |
| 4 | Mountain and plateau access | Creates safer expansion options |
| 5 | Fluoride pathway | Supports later progression and planning |
Prefer a world where cities and key resources sit well above the first lowland water areas, even if the map requires a longer early route.
How Water Moves Across the Planet
Once water becomes available, it follows a simulated cycle. Water evaporates from existing surfaces, clouds move across the planet, rain falls—especially around mountainous terrain—and water flows toward the lowest neighboring areas. This means water management is not only about the location where water first appears.
The terrain determines the direction and speed of movement. A city near a river may remain usable for a long time, while another settlement on a low plain can become surrounded as multiple drainage paths converge. Water should therefore be treated as a moving planetary system rather than a static resource tile.
Mountain ranges, slopes, basins, and low neighbors help predict where rain and runoff will travel. Plan roads and city expansion around those natural flow directions.
Check the Water View
Inspect whether a city, route, or construction zone is already inside a blue area. Use the view as an early warning instead of waiting for visible flooding.
Trace the Lowest Route
Follow nearby slopes and low neighbors to estimate where water will collect. Pay special attention to rivers that pass through city centers or production zones.
Protect the Important Side
Place walls or dams where they can redirect or contain the flow threatening your city, road, or resource route. Avoid placing defenses without considering the destination of redirected water.
Use Pumps Selectively
Pumps can help remove water from vulnerable areas, but they require deliberate placement and may take time to change the surrounding terrain.
Recheck After Warming
Revisit the map after major temperature increases. New streams and water bodies can appear even when the original layout was safe.
| Water System | Main Behavior | Practical Countermeasure |
|---|---|---|
| Evaporation | Increases as temperatures rise | Delay unnecessary warming while preparing |
| Clouds | Move across the planet | Expect changing rainfall zones |
| Mountain rain | Rainfall is especially important near mountains | Avoid blocking critical mountain routes |
| Surface flow | Moves toward lower neighboring terrain | Build around slopes and drainage basins |
| New streams | Can appear during later warming | Keep expansion space outside likely channels |
Walls and pumps are defensive tools, not a simple method for removing every ocean. Their value comes from protecting key infrastructure and influencing local flow. A pump placed in a large body of water may take a long time to create a noticeable opening, so it is usually more practical to defend a city or narrow route than to drain an ocean.
Flood Defense for Cities and Infrastructure
Flooding does not necessarily destroy a settlement immediately. Population can be moved when a city becomes flooded, giving you an opportunity to preserve progress. Even so, relocation can disrupt transport, production, and expansion, so prevention remains preferable when the map allows it.
The best defense is layered. Start with a high-elevation city site, keep important buildings away from obvious channels, and reserve walls or pumps for locations where water threatens a specific objective. A defensive structure should have a clear purpose, such as protecting a city center, maintaining a resource connection, or preventing a river from crossing an industrial district.
Trying to control every stream or empty every ocean can waste time and infrastructure. Protect population centers and essential routes first.
| Threat | Warning Sign | Recommended Response |
|---|---|---|
| Lowland flooding | City or route sits in a blue area | Relocate expansion to higher terrain |
| River through a city | Flow crosses the settlement center | Prepare a wall, dam, or alternate site |
| New stream | Water appears after warming | Pause expansion and reassess drainage |
| Cut resource route | Water blocks a key connection | Protect a second route or pump locally |
| Population displacement | City becomes flooded | Stabilize the area and rebuild on safer ground |
Maintain alternate routes to critical resources when possible. One protected route is useful; two separated routes provide a better response to unexpected streams.
A practical defense order is:
- Protect the city center and population-producing areas.
- Keep critical resource routes above nearby drainage paths.
- Preserve access to construction and production zones.
- Use walls or dams to redirect dangerous flow.
- Use pumps where localized removal supports a specific objective.
- Reassess every defensive placement after the climate advances.
Water can behave slowly enough to create a false sense of security. A settlement may appear stable while water gradually fills low ground nearby. Check the map at normal speed after major temperature changes, then pause construction if the flow direction threatens a critical location.
Water Planning Checklist and Troubleshooting
Water planning works best as a repeated cycle: survey, build, warm, inspect, and adapt. Avoid assuming that the initial map state represents the final planet. The water system changes as the global climate changes, and each new stream can alter the value of nearby terrain.
Before and After Warming:
- Inspect elevation around every city and major resource
- Check the water view for blue areas near settlements
- Mark likely drainage paths through low neighboring terrain
- Keep walls, dams, and pumps available for priority threats
- Recheck routes after new streams or flooding appear
| Problem | Likely Cause | First Action |
|---|---|---|
| Water appears unexpectedly | Global average reaches the transition point | Check the temperature and low-ground areas |
| City becomes surrounded | Water follows lower terrain into the settlement | Protect population and assess relocation |
| New river crosses a town | Later warming creates additional flow | Pause expansion and use local defenses |
| Pump seems ineffective | Large water body refills or changes slowly | Focus the pump on a narrow, important area |
| Route becomes unusable | Water blocks the lowest connection | Build an elevated alternative or redirect flow |
A flooded city is a serious setback, but population movement can preserve the settlement’s progress. Focus on stabilization instead of abandoning the planet immediately.
When a map becomes difficult, separate unavoidable water from preventable mistakes. An ocean or broad lowland may be impossible to control economically, while a short stream crossing a road may be manageable with a wall, dam, or pump. This distinction helps direct limited infrastructure toward the highest-value problem.
Use the following recovery sequence:
- Identify whether the city center, population, or only an outer district is affected.
- Protect the nearest safe route to essential resources.
- Stop placing permanent buildings in the active flow path.
- Redirect or pump water only where it improves the city’s position.
- Move future expansion to elevated ground.
The goal is not to eliminate water from the planet. Water is part of the terraforming simulation, and the strongest settlements adapt their layouts to its movement. High ground, flexible routing, and selective defenses provide more reliable results than trying to force every body of water into a fixed shape.
Plan B: Terraform Water FAQ
Q: At what temperature does water appear in Plan B: Terraform?
Water commonly begins appearing when the global average temperature approaches approximately -20°C. Observations place the transition close to -19.8°C to -20°C, although the visible timing can vary with the planet and local conditions.
Q: Why can liquid water appear while a local area is below freezing?
The main temperature display represents a global average, not the temperature at every point on the planet. Regional conditions, elevation, and seasonal differences can produce colder local readings while water forms elsewhere.
Q: Can walls, dams, and pumps stop all flooding?
They are intended for targeted water management rather than removing entire oceans. Use them to protect cities, redirect dangerous flow, and maintain important routes. Large bodies of water may take considerable time to change.
Q: What should I do if my city is flooded?
Check whether the city center and population are affected, protect essential routes, and move future construction to higher terrain. Flooding can relocate population rather than immediately ending the settlement, so recovery may still be possible.
For the developer discussion covering evaporation, rainfall, water flow, walls, pumps, and flooded population, see the Plan B: Terraform water discussion on Steam.