The current version of the field guide states that the player must place the water wheel on "a source of flowing water, i.e a river." which is misleading because the actual code for the water wheel entity only checks "TFCBlocks.RIVER_WATER" to add to the speed of the rotation. This means that water wheels are entirely useless for players who do not have River biomes nearby and therefore that line should be amended to "the flowing water of a river" to better specific the REQUIREMENT for RIVER WATER that is not clearly stated.

Permalink to the file where I quoted code from: https://github.com/TerraFirmaCraft/TerraFirmaCraft/blob/c25384ccc58e166e5a05de7674ae219222acf961/src/main/java/net/dries007/tfc/common/blockentities/rotation/WaterWheelBlockEntity.java

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