Rivers are thin, lengthy biomes that frequently generate across the world. They typically serve as a division between two different biomes, but can also split a single biome in two. They are filled with water up to sea level, though rivers may run dry in certain areas due to higher than usual elevation. Exposed grass in river biomes takes on a bluish-green hue. Riverbeds consist of dirt, sand, gravel, and clay, and are one of the few places where clay generates, alongside lakes, swamp marshes and ocean hilltops. Seagrass generates atop the riverbed, and sugar cane occasionally generates on the riverbank. Passive mobs cannot spawn within river biomes themselves, but frequently wander into them from the surrounding biomes if they can spawn there. Hostile mobs cannot spawn within river biomes themselves, but frequently wander into them from the surrounding biomes if they can spawn there, however drowned can spawn underwater, as can salmon and squid[JE only].
When generated between two high-elevation biomes, such as mountains and hills, river biomes may pose a fall damage hazard, but are otherwise mostly harmless.
If this biome is used to generate a buffet world, it will look like a shallow ocean, of no more than 10 blocks deep, with mostly sand, dirt, clay and gravel floor and infrequent grassy islands that rarely contain oak trees and, more rarely, pumpkins.
There are two different river biomes.
dec: 7 hex: 7 bin: 111
dec: 11 hex: B bin: 1011
Frozen Rivers replace regular rivers, and only generate within snowy tundra biomes. As the name implies, the top layer of water is entirely frozen, though below the ice is the usual sand, gravel, and clay. While sugar cane can generate alongside a frozen riverbank, it quickly uproots itself after generation due to the water being frozen. Along with salmon and drowned, strays, rabbits, and polar bears can spawn in frozen rivers.
Note that frozen rivers can only cut through snowy tundra, not its variants; if a river generates separating the snowy tundra from one of its variants or any other biome, it will only be partially frozen.
|Java Edition Beta|
|August 18, 2011||Notch tweeted a screenshot of a revamped river biome.|
|1.8||Pre-release||Added rivers. Previously, were generated as part of the terrain generation algorithm.|
|1.13||18w16a||Renamed FrozenRiver to Frozen River.|
|Pocket Edition Alpha|
|0.1.0||Added biomes, including rivers.|
|0.13.0||build 1||Added rabbits, which can spawn in frozen river.|
|0.15.0||build 1||Added strays, which spawn in frozen river biomes.|
|1.0.0||alpha 0.17.0.1||Added polar bears which can spawn in frozen river.|
|1.4.0||beta 22.214.171.124||Added drowned, which spawn in river biomes.|
|beta 126.96.36.199||Added salmon, which spawn in rivers.|
|Rivers now generate with seagrass.|
- Lakes can technically still generate in the waters of rivers and frozen rivers, when either are used as buffet worlds. This can be more clearly seen in frozen river worlds, as holes in the ice.
- Regular rivers can still generate cutting through frozen rivers.
- Both types of rivers override ravines at or close to the surface level, causing the ravine to be abruptly cut off by a wall of stone. However, if the ravine is long enough, it may continue on the other side of the river.
- Oddly ravines can generate underground in river biomes without being cut off.