Flowing River & Render to Texture v.s. Rendering Points

After much manipulation, the velocity grid is now rendering very well to a 1024x1024 texture attached to a plane intersecting the terrain.  Rendering a moving velocity grid as points v.s. rendering off-screen to a texture and applying the texture to a plane resulted in the following findings:

512x512 grid points to screen: 60+ fps
512x512 grid to 512x512 texture map: 60+ fps

1024x1024 grid points to screen: 20+fps
1024x1024 grid to 1024x1024 texture map: 30+ fps

As the rendering to texture method is performed off-screen it seems to be the more resolution scalable solution.  It also results in a convincing water effect when combined with terrain: