Yes, STREETS is a Scrabble word!

Letter values in Scrabble US: S 1, T 1, R 1, E 1, E 1, T 1, S 1.

Is it a valid word?

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

a thoroughfare (usually including sidewalks) that is lined with buildings
the part of a thoroughfare between the sidewalks; the part of the thoroughfare on which vehicles travel
the streets of a city viewed as a depressed environment in which there is poverty and crime and prostitution and dereliction
a situation offering opportunities
people living or working on the same street