{
    "feature": "minecraft:river_disk",
    "placement": [
        {
            "type": "minecraft:count",
            "count": 15
        },
        {
            "type": "minecraft:in_square"
        },
        {
            "type": "minecraft:heightmap",
            "heightmap": "WORLD_SURFACE_WG"
        },
        {
            "type": "minecraft:random_offset",
            "xz_spread": 0,
            "y_spread": 1
        },
        {
            "type": "minecraft:biome"
        }
    ]
}