I guess the correct translations could be the following: Su çok güzel. The water (of a fountain) is very beautiful (is sparkling bright in the sun). or The water (of a lake or a pool) is sparkling splendid in the sun. Maybe normal people will reduce this sentence to not too correct translation provided here as...
"The water is very beautiful".
If people hear this interpretation of the Turkish sentence, they might think into a direction of water qualities: water could be clean, pure and not at all contaminated such as melting and floating ice mountains that was growing there for thousands of years in the Polar Sea. You may explore in Scandinavia. In German you might translate it into "das Wasser ist kristallklar" water is crystal clear". Please advice.