I live along a busy stretch of road. We have an 8' tall fence but want added privacy as well as noise reduction. Plants would be on the N as well as the E side of fence. Looking for something fast growing that would grow taller than 12 foot. Need drought tolerance but would get some watering by irrigation system. Do not mind loss of leaves in fall as long as fairly dense material. Thanks for recommendations!! FYI I have a few Chaste trees and love them, but due to expense want another option. Also like the idea of Pampas grass in corners but they can get quite large and do not want them to grow under fence into neighbors yard.