Outflow
by k8bus
Outflow reshapes hydrology and surface terrain in world generation, letting lakes form at altitudes beyond the hardcoded sea level of Y=63.
What it does
Outflow is a Fabric world generation mod that overhauls how water bodies and terrain surfaces are generated. Instead of placing water at a fixed sea level, it floods depressions according to their height, which produces organic alpine lakes and glaciated valleys. Lake generation is no longer confined to the vanilla Y=63 limit, and the lakes carry smooth bathymetry.
The mod also replaces vanilla steep-terrain handling. Where vanilla places dirt stairs on slopes, Outflow generates stone cliffs instead, and it includes a built-in fix for the surface rules issue tracked as MC-258859. The hydrology changes can run alongside major terrain generators, so large valleys can fill with water bodies. Outflow is server-side only, so the server needs it and players join without installing anything. It is published for Fabric and 26.2 only, under All rights reserved, and is not open source. Its first file was published on 2026-07-10.
Key features
Altitude-free lakes
Lakes form at heights chosen by terrain depressions rather than a hardcoded sea level.
Smooth bathymetry
Lake floors are shaped with smooth depth profiles instead of flat or abrupt basins.
Stone cliffs on steep slopes
Steep terrain generates sheer stone cliffs in place of vanilla dirt stairs.
Built-in surface rule fix
A fix for MC-258859 is included, so the steep surface rules work without a separate patch.
Compatible with terrain generators
The hydrology changes work alongside major terrain generation mods.
Gallery
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
Use cases
Who it’s for: Server owners running Fabric 26.2 who want more realistic water and cliffs in newly generated terrain, and modpack authors combining terrain generators.
How it compares
Better Lava Lakes is a Fabric mod for 26.2 that is client and server, released under the MIT License and not open source; it changes lava lake generation rather than general hydrology. Cliff Face is a Fabric server-side only mod for 1.21 – 1.21.11 under All rights reserved, also not open source, and it concentrates on cliff generation, so its version range does not reach 26.2. Streams Reflowing covers Fabric, Forge and NeoForge for 1.20.1 – 26.3 with a client and server environment, under All rights reserved and not open source.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Outflow | Fabric | 26.2 | Server-side only | 2026-07-11 |
| Better Lava Lakes | Fabric | 26.2 | Client and server | 2026-07-17 |
| Cliff Face | Fabric | 1.21 – 1.21.11 | Server-side only | 2024-10-19 |
| Streams Reflowing | Fabric, Forge and NeoForge | 1.20.1 – 26.3 | Client and server | 2026-10-11 |
Questions
Does Outflow need to be installed on the client?
Which loader and game version does Outflow support?
Can Outflow work with other terrain mods?
In the catalog
Outflow is one of 8,515 World generation mods on ModsFinder, and one of 4,027 World generation mods for Fabric. 13,894 mods support Minecraft 26.2.
Similar mods
What the author says
Outflow is a complete overhaul of Minecraft hydrology and terrain surfaces. Outflow unlocks lake generation at any altitude (breaking the hardcoded Y=63 limit) with smooth bathymetry, and includes a built-in fix for steep surface rules (MC-258859) to generate realistic stone cliffs instead of dirt stairs. This is a…
Official listing
- Modrinth page
- modrinth.com/mod/outflow
- Owner
- k8bus
- Published
- 2026-07-10
- Updated on Modrinth
- 2026-07-11
- Facts verified
- 2026-10-15