How to make gravel spawn on the outline of rivers?

[random shadow]

Hi, I'd like to make something like this for Minecraft and I have never seen anyone else do it before on bedrock so I was wondering if there is a way to make it so that for rivers, there is a gravel outline, or perhaps something similar to this.

[vocal plaza]

Will ur rivers always be at the same y level?

If that's the case use a single blocks feature that replace the river block to gravel with a high ireations under certain y level:)

[random shadow]

Ah, I see

Well do you have an example of using the single block feature?

[random shadow]

also it does seem like that but, is there a way to detect if there is water and there is a block near it that it replaces that block with gravel?

[vocal plaza]

Not to my knowledge

[vocal plaza]

Yeah gimme a sec

{
"format_version": "1.13.0",

"minecraft:single_block_feature": {
    "description": {
        "identifier": "bg:moon_sand_feature"
    },

    "places_block": "bg:moon_sand",

    "enforce_placement_rules": false,
    "enforce_survivability_rules": false,
    "may_replace": ["bg:aurorian_grass"]
}

}

The feature to replace the grass in the water

{
"format_version": "1.18.0",
"minecraft:feature_rules": {
"description": {
"identifier": "bg:moon_sand_feature_rule",
"places_feature": "bg:moon_sand_feature"
},
"conditions": {
"placement_pass": "surface_pass",
"minecraft:biome_filter": [
{
"any_of": [
{
"test": "has_biome_tag",
"operator": "==",
"value": "the_end"
}
]
}
]
},
"distribution": {

        "scatter_chance": 100,
        "iterations": 226224, 
        "coordinate_eval_order": "xzy",
        "x": {
            "distribution": "fixed_grid",
            "extent": [0, 16]
        },
        "y":{
            "distribution": "uniform",
            "extent":[15, 65]
        },
        "z": {
            "distribution": "fixed_grid",
            "extent": [0, 16]
        }
    }
}

}

The feature rule look how I put the y level in between the range:)

@random shadow u understand it?

[random shadow]

Yes, but when you say the grass in the water, can it do the grass on the surface?

[random shadow]

Ah, I see

[vocal plaza]

Yeah just make sure the high y level is above land

[random shadow]

Oh, Alrighty, ty