Project Zomboid Rain Collectors: Thirst-Proof Survival Hacks
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Introduction to Rain Collectors in Project Zomboid
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), including crafting requirements, new mechanics introduced in the past 18 months, water purification methods, and effective storage or plumbing techniques to keep yourself alive. For comprehensive base building tips, see our zombie-proof walls guide.
Key topics we'll explore:
- Crafting rain collector barrels in B41 vs B42 (materials, skills, and recipe changes).
- Using rain barrels: how they fill with rain, capacity, and accessing the water.
- Purifying tainted water and changes to water safety in Build 42.
- Plumbing sinks to rain collectors (differences between B41's and B42's plumbing systems).
- New Build 42 features: fluid system overhaul, weather impacts, and additional water containers.
- Helpful community tips and mods that address rain collector issues or expand functionality.
Crafting a Rain Collector โ Build 41 vs Build 42
Materials & Tools
To craft a rain collector barrel in both Build 41 and Build 42, the core ingredients remain the same. These represent constructing a wooden barrel lined with waterproof material (the garbage bags). Gathering enough garbage bags is often the bottleneck; check kitchen trash cans, dumpsters, sheds, or search zombies carrying trash bags to collect them. For early game survival tips, see our first week survival guide.
In Build 42, an alternative recipe using a tarp instead of garbage bags also exists (listed as "Rain Collector Crate (Tarp)" in carpentry info), which can help if you're short on garbage bags.
Skill Requirements
| Rain Collector Type | Carpentry Level | Water Capacity |
|---|---|---|
| Small Rain Collector Barrel | Carpentry 4 | ~160 units (8 water bottles) |
| Large Rain Collector Barrel | Carpentry 7 | ~400 units (20 water bottles) |
In Build 41, the game offers two sizes of rain collectors, found in the right-click carpentry menu. The small variant is accessible earlier but holds less water.
Rain Collector Appearance
Rain Collector Crate Image
A wooden crate lined with garbage bags to collect rainwater
Some B42 references describe a "Rain Collector Crate" versus "barrel". The "crate" is essentially the small variant โ visually it looks like a wooden crate with a garbage bag liner โ while the "barrel" is the larger variant with metal hoops. Functionally they both collect rain; the difference is capacity and required Carpentry skill.
Finding Pre-Made Barrels
You cannot find craftable rain barrels as loot โ you must build them. However, there are a few pre-existing water barrels in the game world (for example, at the Louisville military camp or certain farms). These metal barrels can hold up to 800 units of water if you manage to relocate one.
Using Rain Collectors: Placement, Filling, and Capacity
Outdoor Placement
Rain collectors must be placed outdoors under open sky to gather rain. If you build one indoors or under a roof overhang, it won't fill. Typically, you'll place it on the ground or on an open roof.
Proper Barrel Placement
Rain collectors placed on a roof for optimal collection
In Build 41, players often put barrels on rooftops specifically above sinks for plumbing (more on that below). In Build 42, this is still possible, but early on there were bugs where barrels wouldn't fill unless the player was nearby in the loaded zone. This was reported in the unstable branch and likely fixed in a patch, but as a precaution, try to situate your base barrels in an area you visit frequently or be present during rainstorms to ensure they update.
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 does eventually fill barrels, but it appears the devs tweaked the collection rates or how rain is simulated. Don't panic if a drizzle doesn't top off your collector โ you may need a heavy storm or more time.
Troughs and Other Water Catchers
Capacity and Storage
As noted in the crafting section, a small rain collector holds ~160 units and a large holds ~400 units of water. In Build 42's new system, they've shifted to measuring in milliliters and liters for liquids, which is why you might see readouts like "25/400 units" or "25.0 L" when checking a barrel.
Build 42 Fluid System
The new fluid interface showing water volume in a barrel
The new fluid system allows mixing liquids, so technically a barrel could contain any fluid โ even gasoline or bleach โ up to capacity.
Accessing Stored Water
To check a barrel's water, right-click it and select "Drink" or "Take water" (in B41). In B42, interacting with fluid objects brings up a unified liquid UI panel if you use "Device Options" or "Show Info" on it. You can also right-click with an empty bottle in hand and select "Fill bottle" from the barrel.
Moving Barrels
Rain collector barrels (wooden) can be picked back up like furniture in Build 41/42. If you use the Pick Up tool, an empty barrel can be carried in your inventory (it's heavy!). This allows you to relocate your barrel โ even to carry it to a water source for manual filling.
CAUTION: Lugging a full barrel will encumber you severely (it can weigh 40 units or more). Always prioritize safety when moving heavy barrels (do it when the area is clear of zombies, and use cars or carts if possible in mods).
In B42, thanks to fluid mixing, you could theoretically take an empty barrel to a river, fill it partially with river water, haul it back, and let rain top it up. However, remember any natural water is tainted; moving a barrel full of water will keep that water inside.
Water Quality: Tainted Rain and Purification Methods
One critical aspect of rain collection is that the water you gather is not immediately safe to drink. 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 Warning
UI showing tainted water label in a bottle
Purifying Water โ Boiling
Pour tainted water into a Cooking Pot or Kettle
Place it on a heat source (campfire, lit stove, or charcoal barbecue)
Heat it until it becomes clean (the item name no longer says "tainted")
In B42, you might get more detailed feedback via the new cooking system โ for instance, water could be shown as heating up in a context menu. Another nuance is that liquids are measured in volume now. You need enough heat and time to raise the temperature of the full volume of water.
Purification Tablets & Filters (Mods)
Vanilla PZ does not yet 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 to purify water without boiling.
Water Filter Straw
Allows you to drink directly from contaminated sources safely.
Water Goes Bad
Makes stored water "go bad" over time if left standing too long, adding a challenge where you must periodically re-boil or treat water.
For most players, boiling your rainwater in batches after each big rain will be sufficient to stay healthy.
Tainted vs. Clean Indicators
Build 41
If you had a bottle of tainted water, it would explicitly say "Tainted Water" in red text. After boiling, it would revert to just "Water".
Build 42
There have been cases where the UI doesn't clearly label a water source as tainted. A quick way to check is to right-click on a water container: if the "Drink" option is greyed out or says "unsafe", that's a giveaway.
WARNING: Your character's health panel will show a sickness or unpleasant taste moodle if you accidentally drink tainted water. Any rain collector should always be assumed tainted.
Plumbing Sinks and Water Fixtures to Rain Collectors
One of the big benefits of rain collector barrels in Project Zomboid is that you can plumb them to your base's sinks, toilets, or tubs to restore running water. This effectively lets you use faucets again even after the city water shuts off, drawing from your stored rainwater.
Plumbing Diagram
Rain barrel placement above sink for proper plumbing
Plumbing in Build 41 vs Build 42
Plumbing Multiple Fixtures
Build 41's plumbing was somewhat limited โ each sink would connect to one barrel above. In Build 42's expanded system, multiple barrels can be linked and even multiple fixtures, though the vanilla game may not fully exploit this yet.
Plumbing Expanded Mod
This mod leverages the new fluid system to allow:
- Up to 9 barrels feeding one sink (useful for bigger bases)
- Removed the one-level restriction so you could pipe water laterally or across floors
- Building actual pipeline objects for a more immersive plumbing setup
For now, stick to the simple one-barrel-per-sink approach in unmodded play.
Indoor vs Outdoor Sinks
A quick debug: if you don't see a "Plumb" option despite correct barrel placement, ensure the sink is surrounded by walls and a roof (you can use a wooden frame and door if needed to simulate a room). Also ensure you placed the sink object after the water shutoff; some pre-existing sinks bug out and require picking up and re-placing them to be plumbable after the water goes off.
Testing Your Plumbing
A handy tip from the community: after plumbing, test the setup by pouring some water into the collector and seeing if it appears at the sink. For instance, if it's not currently raining, take a full bucket or bottle of water and add it to your rain barrel. Then turn on the faucet โ if everything is correct, water should flow (draining from the barrel).
In B42's fluid info panel, you can even see the volume transferring. This confirms the placement is good. If nothing comes out or the sink still says empty, re-check alignment (the red/blue placement diagram in guides can help visualize the acceptable tiles above the sink).
Washer Machines, Showers, Toilets
These fixtures can also be plumbed similarly. Washing machines are great to have working for cleaning clothes when water is off. Plumb them the same way (barrel above, pipe wrench "plumb" menu).
They too will use tainted water if that's what's in the barrel, but for washing clothes or flushing a toilet it doesn't matter. For showers, note that even tainted water can be used to bathe (hygiene isn't tracked except via moodlets for bloodiness).
Advanced Water Storage and Survival Strategies
Additional Water Sources
Water Dispensers
Found in offices and stores. Each dispenser has an internal bottle with ~250 units of clean water. You can take the bottle out and later even refill it with tainted water (but then it becomes tainted).
Wells and Pumps
Farms and some rural areas have water wells or pump stations. If you have a well on your base property, that's a goldmine โ you can bucket water out freely. Just protect it, as wells can't 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 (even large cooking pots) to bring back for boiling.
Bath Tubs, Sinks
Right when the water shuts off, whatever water was left in pipes actually remains in the world. It's worth siphoning all nearby houses' tubs and toilets dry to fill your bottles the moment the outage hits.
Storing Water
Aside from rain barrels, you should stockpile water in portable containers for daily use and travel. Water Bottles are the standard (each holds 1 unit in B41, or 0.25L; in B42 one bottle might be ~500 mL depending on type). Pots, kettles, jugs can hold larger amounts for storage at your base.
Rainfall Variability and Weather
Build 41 already simulated seasons (summers are hotter with thunderstorms, winters cold with occasional precipitation that could be snow). Build 42 is expected to refine weather further. You may find long stretches with no rain, especially in summer or a drought event.
Weather System
Rain collecting in barrels during a storm
Pay attention to the weather broadcast on the radio/TV if available; it can clue you in on upcoming rain. The key is to build enough barrels to get through dry spells. If one barrel is 160 units and each person might consume ~5-10 units a day (between drinking and cooking), 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. If you've boiled water and want to keep it clean, do not mix it with tainted water.
CAUTION: In B42's mixing system, if you pour clean water into a barrel that still has tainted water, the result becomes a mix and thus tainted overall (until boiled again).
There was a bug where rain would slowly replace existing water in a container with tainted water over time โ meaning if you left some clean water in an open barrel, rainfall might contaminate it. It's safest to assume any water in an exposed collector will end up tainted after rain.
Cooking and Water
Both B41 and B42 allow using tainted water in cooking recipes like soups or stews โ but beware, cooking with tainted water does not remove the taint unless the recipe specifically boils it. Generally, boiling soup will purify the water in it, but if you don't cook it long enough or just mix a salad with tainted water (for some reason), you'd still have an issue.
Most cooking recipes that heat the water (soups, pasta, etc.) effectively boil it as part of the process. The B42 crafting notes mention that you can now even cook pasta or rice by adding water from an interior source without needing an external water item โ likely referring to being able to draw from plumbed supply directly.
Fire Safety While Boiling
WARNING: When boiling water on a campfire, do it outside or in a well-ventilated area. In B41/B42, many a safehouse has burned down because a survivor lit a campfire indoors or an oven and forgot about it.
Boiling a large pot can take a while โ don't walk away for too long. Use ovens if you still have power or a controlled campfire. And always have a fire extinguisher or water bucket handy in case of accidental fire (ironic if the quest for water ends up burning your base!).
Notable Mods and Community Add-ons for Water Collection
The Project Zomboid community has created several mods to enhance or tweak water collection and plumbing, especially useful in Build 42's transitional state. Here are a few worth noting:
Plumbing Expanded (B42)
This mod by kspdrgn greatly improves what you can do with plumbing. It allows multiple rain barrels to connect, removes height restrictions, and lets you build actual pipeline objects for a more immersive plumbing setup.
RollBack Rain Collector Barrel
A temporary fix mod (now obsolete for current versions) that added the old B41 rain barrel as a craftable item in B42. It essentially sidestepped the new system to let sinks work like they used to.
Water Filter / Purification Mods
Mods like "True Filter" add chlorine tablets, iodine, etc. and "Water Filter Straw" provides alternative ways to purify water beyond boiling. These can make water management easier or more interesting.
Hydrocraft
A famous mega-mod that adds tons of crafting including more advanced water collection (like constructing wells, makeshift water towers, etc.). It adds items like rain barrels of different sizes, dew collectors, or powered water purifiers.
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 (e.g., they should use the new getFluidAmount() calls, otherwise they may not work right).
Patch History: Water & Rain Collector Changes Over Time
To appreciate how water collection has evolved, let's summarize the key changes in the game's recent history:
Build 41 Stable (2021โ2023)
Rain collector barrels functioned simply. Plumbing existed, with the quirk that plumbed sinks gave clean water. No complex fluid mixing โ water, gasoline, etc. were all separate systems. Last patches of B41 (like 41.73, 41.78) mainly added content or fixes, not drastically altering water mechanics.
Mid 2022 โ Development of Build 42
Indie Stone's dev blogs ("Thursdoids") previewed big changes. The "Liquid Overhaul" was announced. Goals: all liquids in a unified system, allow mixing (for fuel dilution, poisoning drinks, etc.), and tie into the new crafting (distilling, dyeing, etc.). This laid the groundwork for changes to how rain collectors would behave.
Late 2024 โ Build 42 Unstable Release
In December 2024, B42 unstable became available with:
- The new crafting UI โ which confused some about finding the rain barrel recipe
- No sink plumbing โ that feature was absent on launch
- Rain collection bugs โ e.g., barrels not filling when you weren't around
- Basic fluid mixing in place but with issues (like not being able to boil water properly)
- Some items like wells/pumps initially giving tainted water
Early 2025 โ B42 Patches (42.1 to 42.5)
Rapid updates addressed many issues:
- 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.
- 42.5 and 42.6: Ongoing polish โ fixing saucepans being able to boil water again properly, and adding more visual feedback for liquid presence.
Build 42 is still in unstable as of mid-2025. We anticipate a full stable release with all these fixes integrated.
The above 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 โ one where players must consider contamination, volume, and placement much more carefully.