I just read an article on the 15 Insurance Policies You Don't Need', this was on the list. Here's what they said:
7. Water Line Coverage
Water companies have made an aggressive push to sell policies that cover the repair of the water line that runs from the street to your house. The odds are in your favor that you will never use this coverage, particularly if you live in a newer home. If you live an average suburban neighborhood and you do need to repair the water line, the distance to the street is short, the likelihood of a problem is low and repair costs are a few thousand dollars or less. The same goes for policies offered by other utility companies.