Question
I Just moved into a new house and am trying to figure out how much to water the lawn, which has been left unattended for some time and has many dead blades of grass. How much should I water in order to get the lawn to be green again?

Answer
I would have to know a little more about where you live and what kind of lawn you have.  It is usually recommended to add about an inch of water per week to the lawn, spread out over 2-3 waterings.  To find out how much water your sprinkler system applies, put out 3-4 cans (like soup cans) and run the sprinklers for 15 minutes.  Measure the water in the can, and then mutiply by 4 to get the inches per hour.  Say if your system applies 1 inch per hour, you would need to run the sprinklers for 1 hour each week to get 1 inch of water.  Divide that by 3 days and you will have 20 minutes per cycle.

Check out this link for some good info:

http://www.irrigationtutorials.com/irrsch.htm