Masculine gender of water "el agua" in Spanish
Why is water given a masculine gender in Spanish even if it ends in -a, if its a exception it needs to be added in the exception section of words with Feminine endings but actually are masculine in the Masculine and Feminine nouns topic of Grammar section of Spanishdict.com ?
Technically, agua is a feminine noun. Any words that need to agree with it grammatically need to be feminine. For example, in the sentence "The contaminated water", the translation would be el agua contaminada, NOT el agua contaminado. So, technically, agua is feminine.
The el used with the singular agua is a special rule for some words beginning with a stressed "a". Sometimes, when a word begins with a stressed "a", the singular article will be "el"/"un", no "la"/"una", even though the noun remains feminine. When the noun is plural, however, the article regains its "femininity" and becomes "las": "Las aguas".
You can also look at this article here about it. One important part I noticed in that article was that the article only changed if it comes directly before the noun. If there is an adjective between the noun and the article, you should use the "normal" article.
All it is really, is that Spanish doesn't like to run two ' a's together, la agua therefore becomes el agua, just as English doesn't like 'a' aspirin, it becomes ' an' aspirin or an idea, when followed by a vowel.