My style of water varies but on this layout the follwing methods were utilized;
First: seal the underlying styrofoam with Polycrylic water proofing.
Second: Coat the entire waterway with acrylic caulk and paint with glossy blue acrylic craft paints
Third: Recoat the entire river scene with glossy Polycrylic water proofing and create waves and falls with glossy white acrylic caulk.
Note the trees on the rightside riverbank and on the hill close to the watertank, they are JTT (reference only, not promoting the product)
The landscaping scenery to the right of the river is my caulk and paint mix asdescribed in a recent forum post.
Thanks for viewing