It takes 624 gallons of water to cover 1000 sq ft to a depth of 1 inch. Nobody can tell you how much that will cost you - there are parts of the country where water costs 7X what it costs in other areas.

Thanks for the reply. I have my current water bill and figured up my cost per 1,000 gallons. Now I can use your info to get an estimate of how much my bill will increase based on my yards size. Thank you for your help! Also, think it would be too much to ask my family to take weekly showers so I can have a well watered lawn? HAHA!