Decided to try a dry stream

First we got ride of our grass by flipping the sod over. Husband decided he wanted a dry stream just before we were going to put the mulch down. Not really sure what we're doing but we have lots of big river rocks and sand to hold down the landscape plastic. We plan to order a tote of smaller river rocks to fill the river bed. Our eavestrough will drain into it under the pine tree. We will also have to get the shrub stump ground seen in the foreground. ZONE 4