Append the "Water Flow Shader BW" Node-tree into any other Blender 2.8 file.
Connect a Vector from a Texture Coordinate Node into "Vector"
Connect any black and white texture to "Input BW"
Adjust the Settings:
Scale, Detail, Distortion etc...
lastly use the Output of the Node-group as the Input of a bump-node ("height") and plug the bump-node into your shaders normal input
if your Shader does not show anything, or the water refuses to flow, try putting a camera in the scene and render a frame. That will cause Blender to update the Nodetree (specificaly the dependency-graph) and your water should flow after compiling the Shader.
or go into the shader editor and at the beginning of the tree enter "#frame" into the value-node