I followed your instructions. This is what I experienced.
I began to relax with each breath.
I pictured the waterfall. I heard the birds and waterfall. I wasn't sure of the smell.
An image of a South American Indian in native garb, carrying an arrow and bow pointed at me, kept coming up. He wouldn't stop following me and threatening me.
I gravitate towards the waterfall.
My Jack Russell interrupts me. Animals have this weird sense of seeking me out when I am meditating. I don't know why.
I try again. I am in waist deep water, walking my way towards the waterfall. I am forcing the image of the Indian with the arrow out of my mind.
I am under the waterfall. I feel cleansed. A lot of sad emotions being washed away. Images of South American Indians, women and children, looking at me with curiosity keeping coming up. I couldn't fully concentrate with these uncontrolled images popping up. My mind is not as disciplined as I thought. I will try again another time.