FloodWorld
by FishMC
FloodWorld converts air into water while new terrain generates, so caves and low areas fill with water in worlds created after it is installed.
What it does
During chunk generation the mod swaps regular air blocks for water, and cave air as well when that option is enabled. A configurable height sets the depth at which the flooding stops, so water fills only down to a chosen level. Air that was created after a chunk generated stays dry even when the chunk is reloaded, because the change is applied only once at generation time.
Changes apply to newly generated chunks only. Existing terrain is not retroactively flooded, and changing the native flooding setting needs a world restart before it takes effect on new chunks. Cloth Config API is a required dependency, and the options can be edited in-game through ModMenu. It runs on the server alone, so players need nothing extra to join. Files exist for Fabric and NeoForge across 12 release versions, 1.21 – 1.21.11, with the latest Fabric build at 1.0.0 for 1.21.11 and the latest NeoForge build at 2.0.0 for 1.21.1.
Key features
Air replacement
Regular air blocks are replaced with water during chunk generation, filling low ground with a single pass.
Cave flooding
Cave air can also be replaced with water, so underground cavities fill as the world generates.
Configurable water height
A Y level threshold sets how deep water reaches, with options editable through ModMenu and Cloth Config.
Native flooding mode
The native mode places water during generation, which avoids a post-processing tick queue.
Gallery
Compatibility
Latest build for each game version and loader.
1.21.x12 of 12 versions with builds
Only full game releases are shown. This mod publishes no snapshot builds.
Requirements
Dependencies declared by the latest file for each loader.
Required 1
Use cases
Who it’s for: Server owners and survival or adventure players who want new worlds with water in caves and low areas. Existing worlds keep their current terrain.
How it compares
Skychunk is a client and server mod for Fabric and Forge across 1.16.2 – 1.21.1, open source under the MIT License. Chunk Effects is a NeoForge mod for 1.21.5 – 1.21.11, released under the MIT License, but it is not open source and needs only the server. OreFix is server-required with client optional and covers Fabric, Forge, NeoForge and Quilt across 1.18 – 1.21.11, released under the MIT License without an open source claim.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| FloodWorld | Fabric and NeoForge | 1.21 – 1.21.11 | Server-side only | 2026-07-06 |
| Skychunk | Fabric and Forge | 1.16.2 – 1.21.1 | Client and server | 2026-08-15 |
| Chunk Effects | NeoForge | 1.21.5 – 1.21.11 | Server required, client optional | 2025-12-10 |
| OreFix | Fabric, Forge, NeoForge and Quilt | 1.18 – 1.21.11 | Server required, client optional | 2025-08-05 |
Questions
Does FloodWorld need Cloth Config API?
Do players need FloodWorld installed?
Will existing chunks be flooded after installing FloodWorld?
Why does the native flooding setting need a world restart?
In the catalog
FloodWorld is one of 8,515 World generation mods on ModsFinder, and one of 4,027 World generation mods for Fabric. 19,862 mods support Minecraft 1.21.11.
Similar mods
What the author says
## Features FloodWorld is a Fabric mod that replaces all air with water during chunk generation. ## Configuration Requires ModMenu and Cloth Config for in-game configuration
Official listing
- Modrinth page
- modrinth.com/mod/floodworld
- Owner
- FishMC
- Published
- 2026-03-17
- Updated on Modrinth
- 2026-07-06
- Facts verified
- 2026-10-15