Hydrological (Overworld Terrain & Biomes)
by Apothicon
Hydrological is a Forge and NeoForge worldgen mod that replaces the overworld's terrain and biomes with new implementations.
What it does
The mod rebuilds the overworld from scratch, including its continents, and recreates the vanilla biomes in a fantasy style. Alongside them it adds new world presets such as Floating Islands and Floating Caves. Some vanilla biomes are not yet implemented in the beta, and the non-default presets are not fully functional yet, so worlds made with them may show issues.
The mod is server required and client optional: the server needs it to generate the terrain, while players may add it to see the client-side extras. It is released under the MIT License and is open source, with its source code public. Builds cover 1.20.1 – 1.21.11 on Forge, while NeoForge builds start at version 1.21, so NeoForge players on older releases have no file. It has also been used in modpacks.
Key features
Overworld terrain overhaul
New terrain and biome generation replace the default overworld, with continents built for this mod rather than from another terrain mod.
Temperature-based fog
Overworld fog is tinted by temperature, with warm and cold biomes giving different colors, and the setting is enabled by default.
Fireflies at night
Fireflies appear at night around tall grass, adding a small ambient detail to grassland biomes.
Vanilla-style decorative blocks
Decorative blocks in the vanilla style extend the palette with piles of leaves, slabs, walls and dry grass, and several can be toggled off.
Light-emitting blocks
A few blocks, such as blue ice, emit light, changing how caves and snowy areas look after dark.
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 and modpack builders who want a different overworld, with the beta limits in mind. Players on NeoForge should note that the mod starts at 1.21.
How it compares
Old biomes is a client and server mod under the Apache License 2.0, not open source, with files for 1.19.4 – 1.21.8. Rob's Floating Islands is licensed under All rights reserved, not open source, and runs on the client or the server, optional, for 1.16 – 1.21.1. Hydrological is open source under the MIT License and needs only the server, with files for 1.20.1 – 1.21.11.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Hydrological (Overworld Terrain & Biomes) | Forge and NeoForge | 1.20.1 – 1.21.11 | Server required, client optional | 2026-07-05 |
| Old biomes | Forge and NeoForge | 1.19.4 – 1.21.8 | Client and server | 2026-06-22 |
| Rob's Floating Islands | Forge and NeoForge | 1.16 – 1.21.1 | Client or server, optional | 2024-11-17 |
Questions
Which loaders does Hydrological support?
Are all vanilla biomes available yet?
In the catalog
Hydrological (Overworld Terrain & Biomes) is one of 8,515 World generation mods on ModsFinder, and one of 5,058 World generation mods for Forge. 19,862 mods support Minecraft 1.21.11.
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What the author says
Hydrological is a worldgen mod that entirely overhauls the overworld with new implementations of vanilla biomes and unique terrain. This mod is currently in Beta, expect issues such as some vanilla biomes not yet being implemented & non-default world presets not being functional yet.
Official listing
- Modrinth page
- modrinth.com/mod/hydrological
- Owner
- Apothicon
- Published
- 2024-04-09
- Updated on Modrinth
- 2026-07-05
- Facts verified
- 2026-10-15