I have two goldfish ponds, above ground pond liners surrounded by stacking, retaining wall concrete bricks. The chickens get up there to drink out of the ponds. They also go up a ramp to drink out of a 300 gallon tank I got for my ducks. I put a "rescue ramp" in after one hen got blown in by high winds and couldn't get out; she almost drowned (thought she was dead when I found her but I saved her).
I keep a kiddie pool for the ducks, too, which the chickens use for drinking water. Ick. They have waterers, but NOOOO, they want to drink out of the icky duck pool water.
During the summer, a few of the chickens will get INTO the kiddie pool and stand in the water to cool down.
I wouldn't worry about the stream.