Start with an underpainting of burnt sienna and a little white and stain the entire canvas.  Mark your horizon line where water meets land and  mark where the water begins after the triangular sliver of snow on the waters surface.  Now lay in the mid tone of indigo blue (adding white and raw umber to create the color.  The just add raw umber to the blue for the dark parts of the water.  At the top begin adding in some white in the areas of snow in the background trees.

Integrate the lights or tints of the burnt sienna and white mix with the white snow upper right.  To the top left integrate more dark values of the burnt sienna and raw uber mix, and integrate with white for snow.  See below for the brush to use.  It is called flat bristle.

Stroke upwards with the brush laying flat against the canvas to get the effect of textured trees.  This area is a very loose and impressionistic approach since it is in the background.  As we come forward trees will be more in focus.

Now we build in darks adding in trees and some rocks.  Also add in some snow areas as you go.  They can be enhanced later with thicker paint in some areas once this layer dries. Use your values of the burnt sienna and raw umber mix.

Continue with the variety of values as you add in the foreground land, rocks and a few trees. Snow can be completed once the layer of darks drys.

Here some of the rocks in the front were enhanced with more darks.  And then the snow was added with thicker paint with a technique using the tip of the angled brush to give it a feel of “hanging” over the rocks and ground areas.  

Then the water fall was added. Using titanium white ( it can have a drop of blue to tint the white since this part of the water is in partial shadow.  But it is not necessary.)  and using a large flat bristle brush, shown above,  tap top and bottom lines of waterfall with the edge if the brush, and then drag the brush UP on a slight angle and sight curve.  Stroke top to bottom in the same way to join the first stroke.  

Lightly spread with one stroke the top of the white up into the dark part of the waterfall.

Now for this part it is the lighter blue we are looking at the curve of the waterfall.  This is spread with an angled brush in slight a convex arc from top to bottom.  This creates the curve of the waterfall as it moves over the top of the dam. So the top is a convex curve and the bottom white portion is a concave curve.  Very subtle though.  This shot also will show a close up of the white stokes in the waterfall.  

Here I added more of the blue to give a more curved effect of the waterfall over the dam.  And I added shadows in the snow laying on the river to create distance.

This shows the quick sketch for composition of rocks and a few waves of movement.  But make sure you add another layer of the dark blue under tone before proceeding with your rock sketch.

Here is an example of how to handle one of the rocks with water flowing over it.  Start with addding the darkest part of the rock. Add its shape in so the bottom is level with the water.  The skim over the rock and around it with the blue mixture.  This color should pop enough if your base color is correctly done.

Then add your white splashes around the rock and little waves.  Use the point of the brush to “sketch” it in.

Begin spreading the paint of the blue lines layed in to create the tiny waves.  We also added a rock in with a  3 step process.  Start with the dark base aligned with the water.  Then, skim over the top of the rock a lighter version of the rock adding in burnt sienna.  Add the snow and a dark shadow under a few spots of the snow to create a small shadow.  

Here is a close up of a section showing how to get the movement of the water.  Using the light blue mixture, cobalt, white and small amount raw umber, “sketch” in some movement with squiggle lines and strokes.  Then add the white in the same way to represent splashing. 

Here is a close up of an area of rocks with some more of the blue and white water technique. 

More on the water movement is worked on here.  Use same colors of the blue mix and white mix.

Here is a full view of the finished piece. Hope you enjoyed working on this one!!  I sure did!!