Slow shutter effect on water.
If you want to get this soft effect of running water like in a creek or a Waterfalls in your photography, just use a slower shutter speed. I used a shutter speed of 1/10 sec to get this effect. Experiment and try a few combinations. The lower shutter speed will give the flowing water more blur, but you must use a tripod or brace yourself to hold the camera steady when using a slower shutter speed. I was using a bridge railing to brace myself but make sure it can support you.