That's an ENB modification mixed with Realistic Water Two - here http://www.nexusmods.com/skyrim/mods/48938/? edit: You need to download and install ENB. I've not done it, but there are a ton of instructions if you just google it up, then download that preset plus the realistic water two mod and you should be golden. Also, the 'green' effect you see there in the water is called sun scattering, which youll be able to tweak according to the instructions on that mod page Also looks like a 2k texture pack (mebbe the free bethesda one?) and a mod that gives greener, denser foliage (skyrim flora overhaul, perhaps)