For the first layer I took some black acrylic paint and combined it with glue and water to help cement the sand in place.
Then with a paint roller I painted the entire surface twice.
Once that dried I dry brushed on a coffee colored brown on almost the entire surface except for the deepest parts of the water channels.
Once that dried I added in some lighter shades of brown and eventually a buttermilk cream color over successive layers until I achieved this look. I mainly focused on the edges of the water banks and various areas on the flat surface tor represent dry ground.
Next I applied an avocado green in a random pattern to give the impression of plant growth/moss on the surface. In each successive layer I lightened the green with a buttermilk color so that it gives the illusion of depth on a flat surface.
Next I took some dried tree branches that were laying in my back yard and I snapped them into various lengths and glued them to the deeper areas of the water channels.
Next I glued in small clumps of dried Spanish moss in and around the logs. This will hopefully give the impression of long wavy vegetation is growing amongst the downed trees.
Next I glued in clumps of foliage around the moss and other areas of the channels to represent other plant growth along the bottom of the channel.
Finally I started to paint the individual flag stones on the surface of the board. I gave it an initial dark grey stone color as a base but I eventually will be giving it a terra-cotta/sandstone color so that it will stand out from the darker colors.
More updates coming soon!