There are about two dozen different water agencies that serve the greater Sacramento region. And the agency that manages water in a particular place could be different from the city or county responsible for general government services there.
Assuming the water waste you observed occurred in the city of Sacramento, the number to call is the city’s general information number, which is simply 311, if calling from a phone inside the city, or (916) 264-5011, if calling from outside the city. Or you can email the information to firstname.lastname@example.org.
The best bet is to consult The Bee’s map of area water agencies, which allows you to zero in on the place where the water waste was observed. You can click on the location to find contact information for the agency serving that area. We also try to keep the map updated with current water conservation rules in each area. The map can be found at this link: Sacramento Bee water agency map.
When reporting water waste, it’s important to note the street address, date and time of day and a precise description of the waste you observed. It also can be helpful, if relevant, to report how often you see the waste occurring (such as sprinklers flooding a gutter every day at noon).
By the way, if the incident you observed was in the city of Sacramento, you are correct that it is a violation of conservation rules. Washing streets and sidewalks is currently banned in the city.