Cedars are actually native to the Texas Hill Country and are the subject of many myths. They are not the water hogs that some people believe them to be. They are evergreen, provide privacy, prevent erosion, and provide habitat and food for many critters including the endangered golden-cheeked warbler.
They do present some problems. Over time they have moved from the original water courses and ravines and have expanded their range. They outcompete other native plants, they encroach on native grasslands used for forage, and their pollen causes allergies in many people.
Good land management involves judicious removal of some cedars, however the old growth junipers should be protected.
There is a lot of information available on this topic, but we think these are good sources.
Dispelling Common Cedar Myths (Scroll down a little)