Alireza Heidari released another great material (you can also check out his landscape material) for Unreal featuring a number of tweakable parameters. 

The material allows setting up refraction by changing intensity, opacity, and other parameters, add raindrop ripples effect, adjust waves, and more.

Features

• Refraction with adjustable intensity, opacity, etc. (on/off switch)
• Raindrop ripples effect on the surface
• 2 vertex-paint channels enabling you to paint Moss, Leaves, lily pads, or anything you want on the surface of the water
• Adjustable tile size for each vertex paint material. Adjustable speed and intensity for the movement
• Replaceable normal map for waves pattern enabling you to choose your tileable normal map
• Adjustable size, intensity, and speed for waves normal map
• Dynamic foam and ripples around the intersecting objects and shoreline. Adjustable spread radius, speed, opacity, and color for the foam
• More

You can learn more and get the pack for $20+ here.