The variegated plants are Yucca x 'Bright Edge'
The rushes in the background are Juncus patens 'Elk Blue' .

Thank you so much!

Water flows down chain & into a buried cistern.

Rain chains are actually very functional. The rain will drain down the chain, and into a receptacle. So yes, it does guide the rain water from the gutter to the ground. Then you can recycle the water in the receptacle for watering your lawn or plants. It is an eco friendly way to irrigate your lawn, and also looks really cool.

Concrete pavers were cast in place.

I was shocked but just found today at home depot ....in 12 and 16" squares