Kingfisher and Heron

Almost every day for a week, I have been down to Endcliff Park where the beautiful little kingfisher is located. I've tried to get my dream picture off it, which is when it splashed down into the water.
But unfortunately the sun does not reach down to the water yet because it is in a valley and the winter sun is not really bothered to get up as high.
I think that maybe in February the sun is reaching down there, then i will try again or i will try every time i get the opportunity but it will not be easy.
So why is the sun so important then, because the shutter speed is far too low now and I do not want to raise ISO sensitivity that will increase noise to the photo.
And that the sun can give fine effects of splashing water after the bird.
As it is now, so the shutter speed is 1/60 at noon with iso 200 and to get to the picture that I'm talking about, I must have a shutter speed of at least 1/500s or more.
But I can not complain when I have the opportunity to photograph the beautiful kingfisher :))

Camera equipment: Nikon D90 and Nikon 200-400mm F4 lens thar combo gives 300-600mm F4 with D90 (1,5) crop sensor and a tripod.