muddy from the ...

[navi tasan]

Which are correct:

1-The water is muddy from the bridge.
2-The water is muddy from the bridge down.
3-The water is muddy from the bridge on.
4-The water is muddy downstream from the bridge.

Gratefully,
Navi.

[SoothingDave]

4 is the only one which conveys your message clearly. 1 makes it sound like the bridge is made of dirt perhaps and is making the water dirty.