Watering the Grass

We rent, don't pay for water, and don't water our grass.
Our back yard patch of grass is green and full of life! Yet, we never have to water it.
Which is nice for saving water and all. We did have a leak in the back when we first moved in, but that was fixed long ago.
Our front yard, we don't really water either and the grass stays green, but not as green as the back yard. I personally think I use less water if I water it with the hose, than with the sprinkler system, cause then I won't forget to turn the water off. Our neighbors though, they use the system and water is always running down the street to the sewer system. Wasted water!
And the bad thing about that, is when they put the system on, our water pressure goes way down. Which is a bit frustrating when taking a shower!