Final answer:
Near the headwaters, a stream tends to have a steep gradient and fast water velocity due to the narrower channel and higher elevation origins, which contribute to higher flow rates.
Step-by-step explanation:
Near the headwaters source of a stream, the gradient is steep and the water velocity is fast.
Streams begin at a source water which is often in regions with a steep grade, resulting in higher flow rates than the lower elevation stretches of the river. The channel at the headwaters is narrower, which also contributes to the faster current as compared to wider, downstream parts of the river or stream.
As the stream flows away from the source, the channel widens, the gradient decreases, and the water velocity slows down. This is due to the increasing volume of water from tributaries and the decrease in gradient, leading to slower flow and more sedimentation.