I forgot: instead of using hue and saturation, you can use the channel mixer.
To enhance the colours in an image, you can up the slider for the channel and bring the others half of that value down. Then you can tweak with composite.

example: choose the Red channel (top dropdown list). Set the Red slider to, say, 116. Then you have to bring the other two down with 16 in total, if not you change the brightness, or -8 for Green and -8 for Blue. (you can of course play here as you fancy as long as the global plus and minus balance each other. ie: Green -6 and Blue -10)
Do the same for Green: up the Green slider with a value and see that you down the others so that the sum equals that amount. This does not have to be the same as Red!.
Then the same for Blue.

When you give all three the same value up, and the other two for that channel down, for example:

R +16 -8 -8
G -8 +16 -8
B -8 -8 +16

you have a pure saturation result.

When the differ and you start playing with composite (at the bottom) you can change the hue.

Some will say that the advantage is that you have more control, others that you have more space to play in.

This method is meant for subtle changes. Theoretically you can desaturate or oversaturate a lot, but that's not the intention.

I downloaded your original, opened it in PS and looked at the channels. The blue one was the most contrasty, so I copied it and loaded it as a selection. Then back to Layers, I duplicated the layer with your pic and added a layer mask The selection is automatically loaded. This gives a superb mask to enhance depending on the lightness of the work. I set the mode to Multiply. Thedarker parts would not be touched too much by this (black in the mask conceals). The lighter in the pic, the more it would be influenced.
The I added another copy, upped the saturation and changed the hue to greenish. With a mask I took care that only the front water was influenced. (all black with a large soft brush except the water at the front.)

Finally I cropped a bit as the light at the top distracted my attention.

It's a quick indication of a possible road. The lights on the rocks are a bit burned out and should be taken care of. Etc etc.

But this is a great capture, and very inspiring. It's always better to expect something and not getting what you envision than not to expect anything and whash away into total lethargy. Wer'e here to practice, not to be perfect! Cheer up, man: you're one of life's sublime miracles!

I was born in Antwerp about half a century ago and still live there because of my job and the fact that I watch over my mum who is 86 and still lives alone in her house. But I have more friends in France (Provence, Charente, Limousin, Ile-et-Villaine, Côtes d'Armor, Finistère,...) than in Belgium. The most beautiful part of Belgium are the Ardennes. I love the valley of the Semois where my sister has an appartment in Membre. I have lived in London, for a job, long ago, where I learned English, in Lloret-de-Mar, Spain, where I learned nothing, for another job, also long ago, and in Paris ,for yet another job, more recent but still long ago, where I learned French. My ideal home would be central France, somewhere between Creuze, Corrèze and Limousin. If I didn't have to work for a living that is.
More soon on my home-page. I just discovered where it is hidden here on the site.

I went to her website and saw some of her photographs. She is very talented. 
I understand that if you want to, or have to, live from your sellings, you try to protect your work. But on the other hand, I also think that many more people will visit renderosity that a personal website. And there may always be some buyers, collectioners even, or at least friends amongst those. Same goes for Google. Via Google, people will get to her site.
If you don't add a specific line to your page googlebot will always show your images. That's the Internet. There are other sites that are far worse, sites that simply take over the rights of your work the moment you upload something on them.

Because you can rotate the polariser from none to maximum effect ( 90degrees) you can use it at none (no polarising) as a ND4.

As for the Sigma 10-20: I have one and it's a pretty difficult lens to use. On the Canon 350 that is. If you like automatic exposure, you're in trouble as it often cannot focus on anything. Luckily such a wide-angle has an incredible depth so manual focusing is made easy, because, in fact, it's difficult for the same reason the ae doesn't always work. Secondly there's flare. The petal-shaped hood doesn't always help. Third it's nearly impossible to fix a filter on it. I have a pola for it, but that's so thin that it's nearly impossible to screw it off. 
But like you, I'm really more a wide-angle man.
Pity most digital slr have a smaller sensor. The advantage is of course that the problems from the edges are less visible, but to get wide-angle, you need such extreme lenses that they normally fall into the fish-eye range. "Normally" an 18mm would be an incredible wide-angle.

This is a great idea. It brings the members closer together and it is a showcase of the quality of the community. Congrats to all!

Indeed, my point of view seems to be rather controversial. It was not intended as such. I thought it was the general point of view...for digital camera's. I forgot that perhaps you prefer film...

For digitals yes:
Because sensors can do more than the five stops of jpg capture: RAW gives you seven stops or more of sensitivity. 
And also because I prefer (and I thought most photographers would work like that) to take three shots with different stops, put them on layers and composite home with the gradient or mask I create myself. I thought filters would be limiting because they reduce the space to play. Except for the pola filter which cannot be imitated and the infrared I never tried.

Perhaps I have to review my opinion and give them a try. Please don't think I'm mister Knowall who wants to play the professor here. BTW: still looking for what Cokin I have hanging around.

O, I just replied to your filters question, and now I see you have been voted Artist of the Month. 
Congratulations!

Whoops I have to go back to work...

An indiscreet question: why would you need filters? Aren't your pictures good enough? I think they are! And you seem to know enough Photoshop to get any result you fancy.

Everything you do to your initial capture changes it, but seldom, if ever, for the better.
Filters were great in the old days, when a yellow, orange or red filter could make or break those clouds on your black and white work, or when you needed a neutral grey because your film was too sensitive. Or when you wanted the soft-focus effect only a Dutto filter could give (Dutto's have concentric rings that give a softening effect).
Nowadays, and this is my personal opinion of course, is that only a polariser is worth having.
I may have a cokin one hanging around. If I find it, I'll pm you for your adress. 

This makes me think of that short dialogue between Whistler, a great 19th century painter and an amateur. When the amateur said : "I want to paint what I see." , Whistler replied: "then wait 'till you see what you painted."

One of the big problems is that your eyes are always fixing something different. Even the widest wide-angle cannot capture what you see. Add to this sound, smell, the feel of being there  and compare that with a flat pic on a monitor or on a sheet of paper, and your own longing to be back there and relive that , the excitement and concentration.

I guess it's normal and also very positive to be disappointed about your captures. It's never perfect. Luckily the digital darkroom can do a lot to soften the pain. Keep in mind that a number of years ago you risked even more: you came home from a forthnight abroad with loads of slides films (or other) and then you could invest a small fortune to have them developed, knowing that at least two-thirds would not make it to the basic level. Ah! The wish to go back! If I had... I should have...

Now with digital you photograph as you fancy, but then you had to calculate how many shots you could invest in that subject.

It's positive to be critical because it means you want to do better. But don't let it fret your self-confidence too much. Don't compare with others to see how bad and hopeless you are with all your expensive equipment. You are practicing perfection and little by little you learn.

Perhaps the main goal of photography is not to take pictures but to learn to observe how you interpret what you see?