FFWaterFalls
Overview
Makes liquid source blocks fall under gravity.
Features
- Supports water, lava, and modded fluids.
- Configure falling speed and interaction with waterloggable blocks.
FFUtilities is included in this mod JAR; no separate library download is needed.
How falling works
- Liquid source blocks fall when nothing supports them, with a configurable speed (ticks per block) for each liquid.
- No startup delay: unsupported sources begin falling on the next tick.
- Other liquid source blocks count as solid, so a falling source stops on top of them.
- Optional per-liquid removal of a source that lands on another source of the same type (after one fall-speed interval). Settled waterlogged blocks count as sources here.
- Optional per-liquid fall-through of waterloggable blocks, so water can waterlog a fence on the way down and keep falling if there is room.
- When the bottom of a stack falls, the whole column above is scheduled in one go.
- Limits for big collapses keep a dramatic drop from turning into lag.
- Unsupported sources are picked up again across chunk load and unload, and steps into unloaded chunks are retried.
- While a source falls, vanilla fluid spreading is paused so it doesn't fan out mid-air.
- Optional always fall at least one block (on by default): hanging films may drop one extra block, and grounded puddles are left alone.
- Optional vertical fall limit: downward spread stops once the distance already traveled plus the depth below the column top passes a per-fluid limit. Sideways spread is unchanged.
Water and lava react while falling, for example lava landing on water. On NeoForge, reactions added by other mods are picked up too. On Fabric and Forge the vanilla reactions work, but modded fluids that add their own reactions may not react mid-fall.
World-generated fluids
Oceans, lakes and other worldgen liquids stay still by default. They only start falling once activated, for example when a supporting block is broken, a neighbor updates, or a player or dispenser places fluid. The optional rescanChunkOnLoad setting forces a scan whenever a chunk loads (not recommended for normal worlds).
Configuration
Edit ffwaterfalls-common.toml in your config folder, or use the in-game config screen: the Mods list on NeoForge 1.21.1 and newer, or Mod Menu on Fabric 1.21.1 and newer (1.20.1 and 1.20.6 have no generated screen). Options are grouped into Performance, Liquid Properties, Vertical Fall Limit and Compatibility.
| Option | Meaning | Default |
|---|---|---|
maxFallStepsPerTick |
Cap on fall steps processed per dimension per tick | 512 |
maxStackScan |
Max height to scan upward when scheduling a falling stack | 256 |
rescanChunkOnLoad |
Scan each chunk on load and start unsupported fluids falling. Leave off so worldgen fluid stays still until activated | false |
defaultFallSpeed |
Ticks per block for a fluid not in the list below | 6 |
customFluidSpeeds |
"modid:fluid=ticks" entries |
minecraft:water=6, minecraft:lava=12 |
defaultRemoveOnSameSource |
Remove-on-same for a fluid not in the list below | false |
customFluidRemoveOnSameSource |
"modid:fluid=true/false" entries |
minecraft:water=false, minecraft:lava=false |
defaultFallThroughWaterloggable |
Waterlog and pass through waterloggable blocks for a fluid not in the list below | false |
customFluidFallThroughWaterloggable |
"modid:fluid=true/false" entries |
minecraft:water=true, minecraft:lava=false |
enableLimitVerticalFall |
Cap downward spread to the vanilla drop-off reach and reduce sideways level after a fall | true |
alwaysFallAtLeastOneBlock |
One extra downward block per column so hanging films collapse; the vertical limit still applies | true |
disableFluidSpreadMixin |
Turn off the mid-fall spread pause, for compatibility with other fluid mods | false |
Example: to make lava fall as fast as water and a modded acid slowly, set customFluidSpeeds to ["minecraft:water=6", "minecraft:lava=6", "examplemod:acid=20"].
If another mod's fluids misbehave, try disableFluidSpreadMixin = true first. It takes effect after a config reload or restart.
There is no datapack support; modded fluids are added by ID in the per-fluid lists.
Requirements and source version
| Minecraft | Loader | Requires |
|---|---|---|
| 1.20.1 | Fabric | Fabric Loader 0.14.21 or newer and Fabric API |
| 1.20.1 | Forge | Forge 47.1 or newer |
| 1.20.6 | Fabric | Fabric Loader 0.15.11 or newer and Fabric API |
| 1.20.6 | NeoForge | NeoForge 20.6.141 or newer |
| 1.21.1 | Fabric | Fabric Loader 0.16.1 or newer and Fabric API |
| 1.21.1 | NeoForge | NeoForge 21.1.211 or newer |
| 1.21.11 | Fabric | Fabric Loader 0.18.0 or newer and Fabric API |
| 1.21.11 | NeoForge | NeoForge 21.11.45 or newer |
| 26.1 | Fabric | Fabric Loader 0.18.4 or newer, Fabric API and Java 25 |
| 26.1.1 | Fabric | Fabric Loader 0.18.5 or newer, Fabric API and Java 25 |
| 26.1.2 | Fabric | Fabric Loader 0.19.2 or newer, Fabric API and Java 25 |
| 26.1.2 | NeoForge | NeoForge 26.1.2.114 or newer and Java 25 |
| 26.2 | Fabric | Fabric Loader 0.19.3 or newer, Fabric API and Java 25 |
| 26.2 | NeoForge | NeoForge 26.2.0.88 or newer and Java 25 |
| 26.3 | Fabric | Fabric Loader 0.19.5 or newer, Fabric API and Java 25 |
Source version: 0.4.0. FFUtilities 0.2.15 is included in the 26.x jars and 0.2.8 in the others. Water and lava react while falling on every loader; reactions added by other mods only apply on NeoForge.
The Modrinth button is enabled only when a published project link is configured. The source version above may be newer than the latest published file.