Making a river is always a challenge. Mine has about 1,5cm dept and needed four layers of clear resin to accomplished. Some turquoise blue added in the first two layers and the other two were clear to increase the feeling of depth.
I made a frame with two strips of varnished wood and some tape. I then poored the resin layer every three hours
The two first layers have that color
No1
No2
No3
No4 with some more dead leaves in the riverbanks