How to make and use a Rain Collector in Project Zomboid
Introduction to Rain Collectors
When the water shuts off in Project Zomboid, survivors must secure their own supply of safe water. Rain collector barrels become a crucial solution in the late game, providing a renewable source of water once the piped water system fails. This guide covers everything you need to know about making and using rain collectors in Build 41 (stable) and Build 42 (unstable). For information on restoring power to your base, check out our power and water restoration guide.
By the end of this guide, you'll have a comprehensive understanding of how to collect and manage water for your base in Project Zomboid's latest builds, with practical strategies drawn from official sources, patch notes, and experienced players.
Crafting a Rain Collector – Build 41 vs Build 42
Materials & Tools Required
Found in warehouses, construction sites, or learn how to get planks
Found in crates, hardware stores
Found in kitchens, bathrooms, zombies
Must be equipped in primary hand
Build 42 Addition: An alternative recipe using a tarp instead of garbage bags also exists (listed as "Rain Collector Crate (Tarp)" in carpentry info).
Skill Requirements & Barrel Types
| Rain Collector Type | Build 41 Requirement | Build 42 Requirement | Water Capacity |
|---|---|---|---|
| Small Rain Collector / Crate | Carpentry 4 | Carpentry 3 | ~160 units / 8 bottles |
| Large Rain Collector / Barrel | Carpentry 7 | Carpentry 7 | ~400 units / 20 bottles |
| Metal Barrel (pre-existing) | N/A (loot only) | N/A (loot only) | ~800 units |
Figure: An in-game sprite of a small rain collector crate (Carpentry level 3–4 requirement).
How to Find the Recipe
Build 41: Right-click while holding a hammer → Carpentry → Rain Collector Barrel
Build 42: Open the Build Menu (B key) → Carpentry → Building → Outdoors → Rain Collector Crate/Barrel
Common Issue in Build 42
Many players have trouble finding the rain collector recipe in B42 because it moved from the crafting menu to the building menu. You don't need any special magazine to learn it – it's available by default with the required carpentry level.
Finding Pre-Made Barrels
You cannot find craftable rain barrels as loot – you must build them. However, there are a few pre-existing water barrels in the game world:
- Louisville military camp
- Some farms and rural properties
- Riverside tackle shop (community discovery)
These metal barrels can hold up to 800 units of water and can be picked up like furniture with sufficient strength and empty hands.
Using Rain Collectors: Placement, Filling, and Capacity
Outdoor Placement Requirements
- Must be placed outdoors under open sky to gather rain
- Can be placed on the ground or on an open roof
- Will not fill if under a roof overhang or indoors
- For plumbing: typically placed on rooftops above sinks (see Plumbing section)
Figure: Rain collector barrel placed outdoors, exposed to rainfall
How Fast Do Barrels Fill?
Build 41: Rain collectors accumulate water whenever it rains, with the amount depending on rain intensity and duration. Two or three good rainstorms could fill a small barrel to the brim (160 units).
Build 42: Barrels seem to fill much more slowly during light rains. Heavier rain in B42 does eventually fill barrels, but it appears the devs tweaked the collection rates or how rain is simulated.
Note: Early B42 versions had a bug where barrels wouldn't fill unless the player was nearby in the loaded zone. This has been fixed in patch 42.3+.
Troughs and Other Water Catchers
In early B42 builds, craftable feeding troughs (for livestock) were excellent rain catchers. They would fill almost instantly in the rain, far outperforming barrels. This was changed in patch 42.4.0, which capped trough water capacity to only 50 mL.
Capacity and Storage
As noted in the table above:
- Small rain collector holds ~160 units (8 water bottles)
- Large rain collector holds ~400 units (20 water bottles)
- In Build 42's new system, liquids are measured in milliliters/liters
Accessing Stored Water
Build 41: Right-click barrel and select "Drink" or "Take water"
Build 42: Interacting with fluid objects brings up a unified liquid UI panel via "Device Options" or "Show Info"
You can also right-click with an empty bottle in hand and select "Fill bottle" from the barrel.
Important
Remember that collected rainwater is always tainted (unsafe to drink) by default. See the Purification section for how to make it safe.
Moving Barrels
Rain collector barrels can be picked back up like furniture. If you use the Pick Up tool, an empty barrel can be carried in your inventory (it's heavy!).
Build 42 Feature: Thanks to fluid mixing, you can theoretically take an empty barrel to a river, fill it partially with river water, haul it back, and let rain top it up. Moving a barrel full of water will keep that water inside but will be extremely heavy.
Water Quality: Tainted Rain and Purification Methods
Understanding Tainted Water
By default, rainwater in Project Zomboid is "tainted." This also applies to water from rivers, lakes, and un-sanitized wells. Tainted water can cause sickness if consumed untreated.
Tainted Water
Clean Water
Purifying Water – Boiling
The primary way to purify tainted water in PZ is by boiling it. For detailed instructions on water purification methods, see our comprehensive water boiling guide.
Step-by-Step Purification
- Pour tainted water into a Cooking Pot or Kettle
- Create a heat source (campfire, lit stove, charcoal barbecue)
- Light the fire first (important in B42)
- Place the pot of water on the heat source
- Wait until it boils and becomes clean
Build 42 Bug Fix
Early B42 unstable versions had a bug where players couldn't purify water the old way. The workaround was to light the fire first, then add the water container. This has been fixed in patch notes: "Fixed saucepans no longer boiling water".
Purification Tablets & Filters (Mods)
Vanilla PZ does not have chemical water purification (no iodine tablets or bleach-drops mechanics). Boiling is your main option. However, the community has created mods to expand this:
- "True Filter" mod adds chlorine tablets, iodine, and makeshift filters
- "Water Filter Straw" mod allows drinking directly from contaminated sources safely
- "Water Goes Bad" mod makes stored water go bad over time
Tainted vs. Clean Indicators
Build 41: Tainted water explicitly says "Tainted Water" in red text. After boiling, it reverts to just "Water".
Build 42: The UI is similar but there have been cases where it doesn't clearly label a water source as tainted (wells and pumps in early 42.4 were giving tainted water without warning). A quick way to check is to right-click on a water container: if the "Drink" option is greyed out or says "unsafe", it's tainted.
Plumbing Sinks and Water Fixtures to Rain Collectors
Plumbing Overview
One of the big benefits of rain collector barrels is that you can plumb them to your base's sinks, toilets, or tubs to restore running water. However, the plumbing mechanics have changed between B41 and B42. For more information on setting up your base infrastructure, check out our carpentry guide.
Figure: Plumbing a rain barrel above to a sink below
Plumbing in Build 41
- Place a rain barrel one level above the sink you want to supply
- The barrel must be on the tile above or within one tile adjacent (a 3x3 area above the sink)
- The room with the sink must be enclosed ("indoors")
- With a Pipe Wrench in your inventory, right-click the sink and choose "Plumb sink"
- If the barrel has water, the sink will function
B41 Quirk: Plumbing purified the water. Water drawn through a plumbed sink came out as clean, regardless of the barrel's contents.
Plumbing in Build 42
In the initial release of Build 42 unstable (Dec 2024), plumbing was not implemented at all for the new liquid system. By B42.3 updates, the devs restored basic plumbing functionality.
Major Difference: The sink no longer purifies the water. If the source is tainted water, the sink will deliver tainted water to you. This is intentional now.
Example: In B42, you might plumb a kitchen sink to your rooftop barrel. When you fill a bottle from that sink, the bottle's tooltip will say "Tainted Water" (unless your barrel had clean water stored).
Plumbing Multiple Fixtures
Build 41: Each sink would connect to one barrel above.
Build 42: The expanded system potentially allows multiple barrels to be linked and even multiple fixtures, though the vanilla game may not fully exploit this yet.
The Plumbing Expanded mod leverages the new system to allow up to 9 barrels feeding one sink and removes the one-level restriction.
Testing Your Plumbing
After plumbing, test the setup by pouring some water into the collector and seeing if it appears at the sink. If nothing comes out:
- Re-check alignment (barrel must be within 3x3 tiles above sink)
- Ensure you have a pipe wrench
- Verify the sink is inside a proper room
- Try picking up and re-placing the sink
Other Plumbable Fixtures
These fixtures can also be plumbed similarly:
- Washing Machines: Great for cleaning clothes when water is off
- Toilets: Can be plumbed for flushing
- Bathtubs/Showers: Can be filled when plumbed
Even tainted water can be used for washing clothes or bathing without issue.
Advanced Water Storage and Survival Strategies
Additional Water Sources
💧 Water Dispensers
Found in offices and stores. Each dispenser has ~250 units of clean water. You can take the bottle out and refill it later (becomes tainted).
⛲ Wells and Pumps
Farms and rural areas have water wells or pump stations. Provide unlimited clean water (in B41 and fixed B42). Cannot be moved or built in vanilla.
🏞️ Rivers and Lakes
Always available, but always tainted. Good for emergency washing or irrigation. You can fill many containers at once here.
🛁 Pre-Shutoff Fixtures
Right when water shuts off, toilets and bathtubs still hold a few units of water you can collect. Worth siphoning all nearby houses.
Storing Water
Aside from rain barrels, stockpile water in portable containers:
- Water Bottles: Standard portable containers (each holds ~0.25L in B42)
- Pots, kettles, jugs: Hold larger amounts for base storage
- Strategy: Keep several Cooking Pots filled with clean boiled water as reserves
Pro Tip
Fill any empty bottles or kettles whenever you have surplus clean water; you never know when a long drought or power outage might occur.
Rainfall Variability and Weather
Build 42 is expected to refine weather further. You may find long stretches with no rain, especially in summer or during a drought event. Pay attention to weather broadcasts if available.
Many players build multiple barrels over time to capture every drop when it does rain. If one barrel is 160 units and each person consumes ~5-10 units a day, you can estimate how many days your stored water will last.
Preventing Water Decay
In the base game, water doesn't spoil or evaporate. You can store it indefinitely. The only concern is keeping it uncontaminated:
- Do not mix clean water with tainted water
- In B42's mixing system, if you pour clean water into a barrel with tainted water, the result becomes tainted
- Assume any water in an exposed collector will end up tainted after rain
- Store clean water in sealed bottles or pots under a roof
Cooking and Water
Both B41 and B42 allow using tainted water in cooking recipes, but with caveats:
- Cooking with tainted water does not remove the taint unless the recipe specifically boils it
- Most cooking recipes that heat the water (soups, pasta, etc.) effectively boil it
- B42 allows cooking pasta or rice by adding water from a plumbed supply directly
Fire Safety While Boiling
When boiling water on a campfire, do it outside or in a well-ventilated area. Many a safehouse has burned down because a survivor lit a campfire indoors or forgot an oven.
Always have a fire extinguisher or water bucket handy in case of accidental fire.
Notable Mods and Community Add-ons for Water Collection
Plumbing Expanded (B42)
Author: kspdrgn
Greatly improves what you can do with plumbing. Allows multiple rain barrels to connect, removes height restrictions, and lets you build actual pipeline objects.
True Filter
Adds alternative water purification methods beyond boiling:
Water Filter Straw
Adds portable water filtration options:
Water Goes Bad
Increases difficulty by making stored water spoil over time.
Mod Compatibility with B42
When using water-related mods with Build 42, ensure they've been updated for the new fluid API. Outdated mods may not work properly with the new fluid system.
Mods can greatly enhance gameplay or restore expected behavior while B42 is in flux. Just be sure any mod you use is updated for Build 42's API (they should use the new getFluidAmount() calls).
Multiplayer Note
There's discussion about the new fluid mixing system enabling griefing in MP. For example, someone could add bleach or gasoline to a rain barrel. Server admins can use mods to mitigate this or just trust your fellow survivors. Always check your water before drinking in MP!
Patch History: Water & Rain Collector Changes
Rain collector barrels functioned simply. Plumbing existed, with the quirk that plumbed sinks gave clean water. No complex fluid mixing – water, gasoline, etc. were all separate systems.
Indie Stone's dev blogs ("Thursdoids") previewed big changes. The "Liquid Overhaul" was announced. Goals: all liquids in a unified system, allow mixing, and tie into the new crafting system.
- New crafting UI – which confused some about finding the rain barrel recipe
- No sink plumbing – that feature was absent on launch
- Rain collection bugs – barrels not filling when you weren't around
- Wells/pumps initially giving tainted water
42.1 - 42.3: Re-introduced plumbing for sinks using the new system. At first, plumbed sinks still acted like B41 (clean water bug), but by 42.3.1 a fix made them properly output tainted water unless the source is clean.
42.4.0: Feeding trough capacity nerfed to 50 mL to stop unintended use as giant collector, wells and pumps flagged to give clean water again
42.4.1: Some changes to modding hooks (forcing mods to use new fluid calls) were made, ensuring better compatibility for water-related mods.
42.5 and 42.6: Ongoing polish – fixing not being able to manually drink enough to quench thirst, fixing that saucepans can boil water again properly, and other small issues.
Build 42 is still in unstable as of this writing. We anticipate a full stable release of B42 with all these fixes integrated. After that, Build 43 is slated to include NPCs and perhaps more water system interactions.
This timeline shows that water collection went from a fairly static system in B41 to a dynamic, moddable system in B42 that required some growing pains to get right. The result is a more immersive survival experience around water – one where players must consider contamination, volume, and placement much more carefully.
Frequently Asked Questions
Final Thoughts
By understanding these changes and techniques, you can confidently secure water in Project Zomboid whether you're playing on the stable Build 41 or experimenting with the new features of Build 42. Plan ahead, stay flexible with new mechanics, and always keep a pot of water boiling – the zombie apocalypse is unforgiving, but at least you won't die of thirst!
Remember that Build 42 is still evolving, so some behaviors may change in future updates. Check the official forums and patch notes for the latest information on water mechanics.
The sink has to be inside if its outside plumbing option won't show up.
In order to be classified as inside, the sink must be surrounded by walls. This means that the sink must be enclosed by a wooden doorframe, wooden frame, or other similar structure.
The inside of a room can be determined by the sudden change in temperature. When you walk into a room, the temperature change can be saw immediately. The inside of a room is usually warmer than the outside, so the temperature change would be a decrease.
You will need to have the rainwater collector barrels at one floor above the sink.
The red tiles in the screenshot correspond to the location of the downstairs sink, and the outer circle of blue and green tiles corresponds to the location where the rainwater collector can be placed. The rainwater collector cannot be placed in the middle of the red tile.
Plumbing a Sink with the pipe wrench
After you successfully plumb the sink, You can test the sink by adding water to the rainwater collector. To do this, simply fill a container with water and pour it into the rainwater collector. If the sink drains properly, then the placement is successful. If not, you may need to adjust the placement of the collector or the sink itself.
Conclusion
A rain collector is a simple and effective way to collect water for use in Project Zomboid. By following the steps outlined in this article, players can easily make and use a rain collector to help them survive in the zombie apocalypse. With a reliable source of water, players can stay alive for as long as possible and have a chance to beat the game.