The picture looks like a lot of silt in the water, a dam slows the water flow down which helps a lot of it drop to the bottom.
Although the clear difference in each side does seem surprising to me, perhaps the dam is fine enough that sand/silt builds up on it and it acts as a filter as well.
The picture looks like a lot of silt in the water, a dam slows the water flow down which helps a lot of it drop to the bottom.
Although the clear difference in each side does seem surprising to me, perhaps the dam is fine enough that sand/silt builds up on it and it acts as a filter as well.