Here in the Las Vegas area the local water company is the Las Vegas Valley Water District.
Their office is located at:
1001 South Valley View Blvd.
Las Vegas, Nevada 89153
Customer Service Phone Number:
702-870-2011 or 800-252-2011
8:00am to 5:00pm Monday - Friday
Information on turning on service can be found online at the following link:
Start or Transfer Water Service
The following link will take you to the Las Vegas Valley Water District's Web Site.
Las Vegas Valley Water District