But What am I that Dare

That stream I noticed was flowing with water again just a few days ago, must have gone dry soon after, some worker further upstream having turned off the tap. Revisiting the same spot this morning and finding it dry, I figured it to be a good opportunity to walk up the course and see what there was to see. I had not gone a hundred feet or so when the sound of water came to me - a last trickle, or so I thought. But no, instead it was the head of the stream flow coming back down - someone further up the line had turned the tap back on.  So much for that little bit of exploring. Slowly I retreated back downstream keeping just ahead of the water, watching it surround then submerge bleached stones, gathering up dry leaves and carrying them swirling along, watching it back up behind obstructions then overwhelm what had tried to contain it. 
Finn (the dog) and I watched with, perhaps, too great curiosity a week ago as a stream patiently made its way down the gutter flow line when someone up the street left their sprinklers on a little too long.

leading edge[?] of the flow

Now that I think about it, I have watched that sort of thing my whole life. Water charting its course - down a windshield, along the gutter, in a dry stream bed. 

Okay, enough of nerding out, time to make tracks.

"Through intricate motions ran

Stream and gliding sun...

But what am I that dare...

What motion of the sun or stream

Or eyelid shot the gleam

That pierced my body through..."

(Yeats)