Yes, WATERBUCKS is a Scrabble word!

Letter values in Scrabble US: W 4, A 1, T 1, E 1, R 1, B 3, U 1, C 3, K 5, S 1.

Is it a valid word?

WATERBUCKS is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

any of several large African antelopes of the genus Kobus having curved ridged horns and frequenting e.g. swamps and rivers