Sandbag cofferdam should be enough. It is set as a triangular sandbag cofferdam with a width of 2m * a height of 2m, about 250 yuan per meter.

Not to mention earthwork excavation, it mainly depends on the distance you transport, and the person said 26 yuan/Fang is similar.

Backfilling depends on the material you backfill. If it is by the river, it is recommended that you backfill stones and graded sand, and the general outline is above 100 per square meter.

The dam depends on how wide you want to make it, whether it is a masonry dam or a concrete dam.