Explanation:

There isn't any water in the overhead tank.
Some is used in affirmative sentences, and also when asking for or offering something.
Any is used in negative and interrogative sentences.
A little is used with uncountable nouns: a little cheese
We use a lot of and lots of in informal styles. Lots of is more informal than a lot of. A lot of and lots of can both be used with plural countable nouns and with singular uncountable nouns for affirmatives, negatives, and questions: We've got lots of things to do.